From 554c5c95b699608e759890e344a4befb43020275 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 11:21:00 +0100
Subject: [PATCH 01/22] update stack resolver to lts 9.0

---
 stack.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stack.yaml b/stack.yaml
index fc491c7..4c7e5e1 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-8.15
+resolver: lts-9.0
 packages:
 - '.'
 extra-deps: []

From de8db14301f8117368509a544b7706ee9f5c2efb Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 12:14:59 +0100
Subject: [PATCH 02/22] move Types to separate library

---
 app/Main.hs                                       |  3 ++-
 psc-package.cabal                                 | 12 ++++++++++--
 {app => src/Language/PureScript/Package}/Types.hs |  2 +-
 3 files changed, 13 insertions(+), 4 deletions(-)
 rename {app => src/Language/PureScript/Package}/Types.hs (98%)

diff --git a/app/Main.hs b/app/Main.hs
index 968e369..5f25d00 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -36,7 +36,8 @@ import qualified System.Process as Process
 import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
-import           Types (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+
+import           Language.PureScript.Package.Types (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
diff --git a/psc-package.cabal b/psc-package.cabal
index e3533bb..48fd2ce 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -13,8 +13,17 @@ build-type:          Simple
 extra-source-files:  README.md
 cabal-version:       >=1.10
 
+library
+    hs-source-dirs:      src
+    exposed-modules:     Language.PureScript.Package.Types
+    build-depends:       base >= 4.7 && < 5,
+                         aeson -any,
+                         text
+    default-language:    Haskell2010
+
 executable psc-package
-    build-depends: base >=4 && <5,
+    build-depends: psc-package,
+                   base >=4 && <5,
                    aeson -any,
                    aeson-pretty -any,
                    async -any,
@@ -28,7 +37,6 @@ executable psc-package
                    turtle ==1.3.*
     main-is: Main.hs
     other-modules: Paths_psc_package
-                   Types
     buildable: True
     hs-source-dirs: app
     ghc-options: -Wall -O2 -threaded -rtsopts -with-rtsopts=-N
diff --git a/app/Types.hs b/src/Language/PureScript/Package/Types.hs
similarity index 98%
rename from app/Types.hs
rename to src/Language/PureScript/Package/Types.hs
index 2d5e4e5..02ef738 100644
--- a/app/Types.hs
+++ b/src/Language/PureScript/Package/Types.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 
-module Types
+module Language.PureScript.Package.Types
   ( PackageName
   , mkPackageName
   , runPackageName

From db67ddcf506b45a1cb4658f62e326878228dad18 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 12:24:25 +0100
Subject: [PATCH 03/22] move PackageConfig into Types

---
 app/Main.hs                              |  9 +--------
 src/Language/PureScript/Package/Types.hs | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index 5f25d00..43016f5 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -37,7 +37,7 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import           Language.PureScript.Package.Types (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -49,13 +49,6 @@ exitWithErr errText = errT errText >> exit (ExitFailure 1)
 packageFile :: Path.FilePath
 packageFile = "psc-package.json"
 
-data PackageConfig = PackageConfig
-  { name    :: PackageName
-  , depends :: [PackageName]
-  , set     :: Text
-  , source  :: Text
-  } deriving (Show, Generic, Aeson.FromJSON, Aeson.ToJSON)
-
 pathToTextUnsafe :: Turtle.FilePath -> Text
 pathToTextUnsafe = either (error "Path.toText failed") id . Path.toText
 
diff --git a/src/Language/PureScript/Package/Types.hs b/src/Language/PureScript/Package/Types.hs
index 02ef738..7838c36 100644
--- a/src/Language/PureScript/Package/Types.hs
+++ b/src/Language/PureScript/Package/Types.hs
@@ -1,7 +1,10 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
 
 module Language.PureScript.Package.Types
-  ( PackageName
+  ( PackageConfig(..)
+  , PackageName
   , mkPackageName
   , runPackageName
   , preludePackageName
@@ -15,6 +18,14 @@ import           Data.Char (isAscii, isLower, isDigit)
 import           Data.Monoid ((<>))
 import           Data.Text (Text)
 import qualified Data.Text as T
+import           GHC.Generics (Generic)
+
+data PackageConfig = PackageConfig
+  { name    :: PackageName
+  , depends :: [PackageName]
+  , set     :: Text
+  , source  :: Text
+  } deriving (Show, Generic, FromJSON, ToJSON)
 
 newtype PackageName
   = PackageName Text

From a164521c5ded39955ea4eac4c8934b1c38be18c9 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 12:30:05 +0100
Subject: [PATCH 04/22] move PackageInfo to Types

---
 app/Main.hs                              | 11 +----------
 src/Language/PureScript/Package/Types.hs |  7 +++++++
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index 43016f5..2317296 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
@@ -27,7 +25,6 @@ import qualified Data.Text.Read as TR
 import           Data.Traversable (for)
 import           Data.Version (Version(..), parseVersion, showVersion)
 import qualified Filesystem.Path.CurrentOS as Path
-import           GHC.Generics (Generic)
 import qualified Options.Applicative as Opts
 import qualified Paths_psc_package as Paths
 import           System.Environment (getArgs)
@@ -37,7 +34,7 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageInfo(..), repo, version, dependencies, PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -89,12 +86,6 @@ writePackageFile =
   writeTextFile packageFile
   . packageConfigToJSON
 
-data PackageInfo = PackageInfo
-  { repo         :: Text
-  , version      :: Text
-  , dependencies :: [PackageName]
-  } deriving (Show, Eq, Generic, Aeson.FromJSON, Aeson.ToJSON)
-
 type PackageSet = Map.Map PackageName PackageInfo
 
 cloneShallow
diff --git a/src/Language/PureScript/Package/Types.hs b/src/Language/PureScript/Package/Types.hs
index 7838c36..1bd44fb 100644
--- a/src/Language/PureScript/Package/Types.hs
+++ b/src/Language/PureScript/Package/Types.hs
@@ -4,6 +4,7 @@
 
 module Language.PureScript.Package.Types
   ( PackageConfig(..)
+  , PackageInfo(..)
   , PackageName
   , mkPackageName
   , runPackageName
@@ -27,6 +28,12 @@ data PackageConfig = PackageConfig
   , source  :: Text
   } deriving (Show, Generic, FromJSON, ToJSON)
 
+data PackageInfo = PackageInfo
+  { repo         :: Text
+  , version      :: Text
+  , dependencies :: [PackageName]
+  } deriving (Show, Eq, Generic, FromJSON, ToJSON)
+
 newtype PackageName
   = PackageName Text
   deriving (Show, Eq, Ord)

From a04b9361af96cab20c74a527b3e1498dc83dd243 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 12:39:45 +0100
Subject: [PATCH 05/22] turn on ghc warnings

---
 psc-package.cabal | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/psc-package.cabal b/psc-package.cabal
index 48fd2ce..b451dfe 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -15,6 +15,7 @@ cabal-version:       >=1.10
 
 library
     hs-source-dirs:      src
+    ghc-options:         -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -fwarn-identities
     exposed-modules:     Language.PureScript.Package.Types
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
@@ -39,5 +40,5 @@ executable psc-package
     other-modules: Paths_psc_package
     buildable: True
     hs-source-dirs: app
-    ghc-options: -Wall -O2 -threaded -rtsopts -with-rtsopts=-N
+    ghc-options: -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -O2 -threaded -rtsopts -with-rtsopts=-N
     default-language:    Haskell2010

From 176d90e1814a9c8b40d2b7b4e580d4e649ed9108 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 13:55:54 +0100
Subject: [PATCH 06/22] move PackageName to separate module

---
 app/Main.hs                                   |  3 +-
 psc-package.cabal                             |  3 +-
 src/Language/PureScript/Package/Types.hs      | 82 +-----------------
 .../PureScript/Package/Types/PackageName.hs   | 85 +++++++++++++++++++
 4 files changed, 92 insertions(+), 81 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Types/PackageName.hs

diff --git a/app/Main.hs b/app/Main.hs
index 2317296..a19953e 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,7 +34,8 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageInfo(..), repo, version, dependencies, PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageInfo(..), repo, version, dependencies)
+import           Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
diff --git a/psc-package.cabal b/psc-package.cabal
index b451dfe..52a71dc 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -16,7 +16,8 @@ cabal-version:       >=1.10
 library
     hs-source-dirs:      src
     ghc-options:         -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -fwarn-identities
-    exposed-modules:     Language.PureScript.Package.Types
+    exposed-modules:     Language.PureScript.Package.Types,
+                         Language.PureScript.Package.Types.PackageName
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
                          text
diff --git a/src/Language/PureScript/Package/Types.hs b/src/Language/PureScript/Package/Types.hs
index 1bd44fb..fcf3e2f 100644
--- a/src/Language/PureScript/Package/Types.hs
+++ b/src/Language/PureScript/Package/Types.hs
@@ -5,22 +5,14 @@
 module Language.PureScript.Package.Types
   ( PackageConfig(..)
   , PackageInfo(..)
-  , PackageName
-  , mkPackageName
-  , runPackageName
-  , preludePackageName
-  , untitledPackageName
   ) where
 
-import           Control.Category ((>>>))
-import           Data.Aeson (FromJSON, ToJSON, FromJSONKey(..), ToJSONKey(..), ToJSONKeyFunction(..), FromJSONKeyFunction(..), parseJSON, toJSON, withText)
-import qualified Data.Aeson.Encoding as AesonEncoding
-import           Data.Char (isAscii, isLower, isDigit)
-import           Data.Monoid ((<>))
+import           Data.Aeson (FromJSON, ToJSON)
 import           Data.Text (Text)
-import qualified Data.Text as T
 import           GHC.Generics (Generic)
 
+import           Language.PureScript.Package.Types.PackageName (PackageName)
+
 data PackageConfig = PackageConfig
   { name    :: PackageName
   , depends :: [PackageName]
@@ -33,71 +25,3 @@ data PackageInfo = PackageInfo
   , version      :: Text
   , dependencies :: [PackageName]
   } deriving (Show, Eq, Generic, FromJSON, ToJSON)
-
-newtype PackageName
-  = PackageName Text
-  deriving (Show, Eq, Ord)
-
-instance ToJSON PackageName where
-  toJSON (PackageName t) = toJSON t
-
-instance FromJSON PackageName where
-  parseJSON =
-    withText "package name" fromText
-
-fromText :: Monad m => Text -> m PackageName
-fromText t =
-  case mkPackageName t of
-    Right pkgName -> pure pkgName
-    Left errs -> fail $ "Invalid package name: " <> show errs
-
-instance ToJSONKey PackageName where
-  toJSONKey =
-    ToJSONKeyText
-      runPackageName
-      (AesonEncoding.text . runPackageName)
-
-instance FromJSONKey PackageName where
-  fromJSONKey =
-    FromJSONKeyTextParser fromText
-
-data PackageNameError
-  = NotEmpty
-  | TooLong Int
-  | InvalidChars String
-  | RepeatedSeparators
-  | MustNotBeginSeparator
-  | MustNotEndSeparator
-  deriving (Show, Eq, Ord)
-
--- | Smart constructor for package names. Based on Bower's requirements for
--- | package names.
-mkPackageName :: Text -> Either PackageNameError PackageName
-mkPackageName = fmap PackageName . validateAll validators
-  where
-  dashOrDot = ['-', '.']
-  validateAll vs x = mapM_ (validateWith x) vs >> return x
-  validateWith x (p, err)
-    | p x       = Right x
-    | otherwise = Left (err x)
-  validChar c = isAscii c && (isLower c || isDigit c || c `elem` dashOrDot)
-  validators =
-      [ (not . T.null, const NotEmpty)
-      , (T.all validChar, InvalidChars . T.unpack . T.filter (not . validChar))
-      , (firstChar (`notElem` dashOrDot), const MustNotBeginSeparator)
-      , (lastChar (`notElem` dashOrDot), const MustNotEndSeparator)
-      , (not . T.isInfixOf "--", const RepeatedSeparators)
-      , (not . T.isInfixOf "..", const RepeatedSeparators)
-      , (T.length >>> (<= 50), TooLong . T.length)
-      ]
-  firstChar p str = not (T.null str) && p (T.index str 0)
-  lastChar p = firstChar p . T.reverse
-
-runPackageName :: PackageName -> Text
-runPackageName (PackageName t) = t
-
-preludePackageName :: PackageName
-preludePackageName = PackageName "prelude"
-
-untitledPackageName :: PackageName
-untitledPackageName = PackageName "untitled"
diff --git a/src/Language/PureScript/Package/Types/PackageName.hs b/src/Language/PureScript/Package/Types/PackageName.hs
new file mode 100644
index 0000000..0075a2e
--- /dev/null
+++ b/src/Language/PureScript/Package/Types/PackageName.hs
@@ -0,0 +1,85 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Language.PureScript.Package.Types.PackageName
+  ( PackageName
+  , mkPackageName
+  , runPackageName
+  , preludePackageName
+  , untitledPackageName
+  ) where
+
+import           Control.Category ((>>>))
+import           Data.Aeson (FromJSON, ToJSON, FromJSONKey(..), ToJSONKey(..), ToJSONKeyFunction(..), FromJSONKeyFunction(..), parseJSON, toJSON, withText)
+import qualified Data.Aeson.Encoding as AesonEncoding
+import           Data.Char (isAscii, isLower, isDigit)
+import           Data.Monoid ((<>))
+import           Data.Text (Text)
+import qualified Data.Text as T
+
+newtype PackageName
+  = PackageName Text
+  deriving (Show, Eq, Ord)
+
+instance ToJSON PackageName where
+  toJSON (PackageName t) = toJSON t
+
+instance FromJSON PackageName where
+  parseJSON =
+    withText "package name" fromText
+
+fromText :: Monad m => Text -> m PackageName
+fromText t =
+  case mkPackageName t of
+    Right pkgName -> pure pkgName
+    Left errs -> fail $ "Invalid package name: " <> show errs
+
+instance ToJSONKey PackageName where
+  toJSONKey =
+    ToJSONKeyText
+      runPackageName
+      (AesonEncoding.text . runPackageName)
+
+instance FromJSONKey PackageName where
+  fromJSONKey =
+    FromJSONKeyTextParser fromText
+
+data PackageNameError
+  = NotEmpty
+  | TooLong Int
+  | InvalidChars String
+  | RepeatedSeparators
+  | MustNotBeginSeparator
+  | MustNotEndSeparator
+  deriving (Show, Eq, Ord)
+
+-- | Smart constructor for package names. Based on Bower's requirements for
+-- | package names.
+mkPackageName :: Text -> Either PackageNameError PackageName
+mkPackageName = fmap PackageName . validateAll validators
+  where
+  dashOrDot = ['-', '.']
+  validateAll vs x = mapM_ (validateWith x) vs >> return x
+  validateWith x (p, err)
+    | p x       = Right x
+    | otherwise = Left (err x)
+  validChar c = isAscii c && (isLower c || isDigit c || c `elem` dashOrDot)
+  validators =
+      [ (not . T.null, const NotEmpty)
+      , (T.all validChar, InvalidChars . T.unpack . T.filter (not . validChar))
+      , (firstChar (`notElem` dashOrDot), const MustNotBeginSeparator)
+      , (lastChar (`notElem` dashOrDot), const MustNotEndSeparator)
+      , (not . T.isInfixOf "--", const RepeatedSeparators)
+      , (not . T.isInfixOf "..", const RepeatedSeparators)
+      , (T.length >>> (<= 50), TooLong . T.length)
+      ]
+  firstChar p str = not (T.null str) && p (T.index str 0)
+  lastChar p = firstChar p . T.reverse
+
+runPackageName :: PackageName -> Text
+runPackageName (PackageName t) = t
+
+preludePackageName :: PackageName
+preludePackageName = PackageName "prelude"
+
+untitledPackageName :: PackageName
+untitledPackageName = PackageName "untitled"

From 9eece6e93f1d6bf03b2952796ffc27ef318edfcb Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 14:01:22 +0100
Subject: [PATCH 07/22] move PackageConfig type to separate module

---
 app/Main.hs                                    |  3 ++-
 psc-package.cabal                              |  1 +
 src/Language/PureScript/Package/Types.hs       | 10 +---------
 .../PureScript/Package/Types/PackageConfig.hs  | 18 ++++++++++++++++++
 4 files changed, 22 insertions(+), 10 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Types/PackageConfig.hs

diff --git a/app/Main.hs b/app/Main.hs
index a19953e..6c9f522 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,7 +34,8 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import           Language.PureScript.Package.Types (PackageConfig(..), name, depends, set, source, PackageInfo(..), repo, version, dependencies)
+import           Language.PureScript.Package.Types (PackageInfo(..), repo, version, dependencies)
+import           Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source)
 import           Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
diff --git a/psc-package.cabal b/psc-package.cabal
index 52a71dc..56147f6 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -17,6 +17,7 @@ library
     hs-source-dirs:      src
     ghc-options:         -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -fwarn-identities
     exposed-modules:     Language.PureScript.Package.Types,
+                         Language.PureScript.Package.Types.PackageConfig,
                          Language.PureScript.Package.Types.PackageName
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
diff --git a/src/Language/PureScript/Package/Types.hs b/src/Language/PureScript/Package/Types.hs
index fcf3e2f..9a4d498 100644
--- a/src/Language/PureScript/Package/Types.hs
+++ b/src/Language/PureScript/Package/Types.hs
@@ -3,8 +3,7 @@
 {-# LANGUAGE DeriveGeneric #-}
 
 module Language.PureScript.Package.Types
-  ( PackageConfig(..)
-  , PackageInfo(..)
+  ( PackageInfo(..)
   ) where
 
 import           Data.Aeson (FromJSON, ToJSON)
@@ -13,13 +12,6 @@ import           GHC.Generics (Generic)
 
 import           Language.PureScript.Package.Types.PackageName (PackageName)
 
-data PackageConfig = PackageConfig
-  { name    :: PackageName
-  , depends :: [PackageName]
-  , set     :: Text
-  , source  :: Text
-  } deriving (Show, Generic, FromJSON, ToJSON)
-
 data PackageInfo = PackageInfo
   { repo         :: Text
   , version      :: Text
diff --git a/src/Language/PureScript/Package/Types/PackageConfig.hs b/src/Language/PureScript/Package/Types/PackageConfig.hs
new file mode 100644
index 0000000..88ee8ca
--- /dev/null
+++ b/src/Language/PureScript/Package/Types/PackageConfig.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+
+module Language.PureScript.Package.Types.PackageConfig (PackageConfig(..)) where
+
+import           Data.Aeson (FromJSON, ToJSON)
+import           Data.Text (Text)
+import           GHC.Generics (Generic)
+
+import           Language.PureScript.Package.Types.PackageName (PackageName)
+
+data PackageConfig = PackageConfig
+  { name    :: PackageName
+  , depends :: [PackageName]
+  , set     :: Text
+  , source  :: Text
+  } deriving (Show, Generic, FromJSON, ToJSON)

From a1ab389d6ac453acbaa388242d35176dc1d1c126 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 14:05:41 +0100
Subject: [PATCH 08/22] move PackageInfo to separate module

---
 app/Main.hs                                                 | 6 +++---
 psc-package.cabal                                           | 4 ++--
 .../PureScript/Package/{Types.hs => Types/PackageInfo.hs}   | 4 +---
 3 files changed, 6 insertions(+), 8 deletions(-)
 rename src/Language/PureScript/Package/{Types.hs => Types/PackageInfo.hs} (85%)

diff --git a/app/Main.hs b/app/Main.hs
index 6c9f522..6758c7c 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,9 +34,9 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import           Language.PureScript.Package.Types (PackageInfo(..), repo, version, dependencies)
-import           Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source)
-import           Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source)
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
+import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
diff --git a/psc-package.cabal b/psc-package.cabal
index 56147f6..a62ef84 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -16,8 +16,8 @@ cabal-version:       >=1.10
 library
     hs-source-dirs:      src
     ghc-options:         -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -fwarn-identities
-    exposed-modules:     Language.PureScript.Package.Types,
-                         Language.PureScript.Package.Types.PackageConfig,
+    exposed-modules:     Language.PureScript.Package.Types.PackageConfig,
+                         Language.PureScript.Package.Types.PackageInfo,
                          Language.PureScript.Package.Types.PackageName
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
diff --git a/src/Language/PureScript/Package/Types.hs b/src/Language/PureScript/Package/Types/PackageInfo.hs
similarity index 85%
rename from src/Language/PureScript/Package/Types.hs
rename to src/Language/PureScript/Package/Types/PackageInfo.hs
index 9a4d498..bb5486c 100644
--- a/src/Language/PureScript/Package/Types.hs
+++ b/src/Language/PureScript/Package/Types/PackageInfo.hs
@@ -2,9 +2,7 @@
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DeriveGeneric #-}
 
-module Language.PureScript.Package.Types
-  ( PackageInfo(..)
-  ) where
+module Language.PureScript.Package.Types.PackageInfo (PackageInfo(..)) where
 
 import           Data.Aeson (FromJSON, ToJSON)
 import           Data.Text (Text)

From f9586d4e83e9e57f57230c2cc8f28876797719df Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 14:44:39 +0100
Subject: [PATCH 09/22] move PackageConfig functions to module

---
 app/Main.hs                                   | 34 +-------------
 psc-package.cabal                             |  2 +
 .../PureScript/Package/Types/PackageConfig.hs | 47 ++++++++++++++++++-
 3 files changed, 48 insertions(+), 35 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index 6758c7c..eb19f9c 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -34,7 +34,7 @@ import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source)
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
 import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
 
@@ -45,36 +45,9 @@ exitWithErr :: Text -> IO a
 exitWithErr errText = errT errText >> exit (ExitFailure 1)
   where errT = traverse Turtle.err . textToLines
 
-packageFile :: Path.FilePath
-packageFile = "psc-package.json"
-
 pathToTextUnsafe :: Turtle.FilePath -> Text
 pathToTextUnsafe = either (error "Path.toText failed") id . Path.toText
 
-readPackageFile :: IO PackageConfig
-readPackageFile = do
-  exists <- testfile packageFile
-  unless exists $ exitWithErr "psc-package.json does not exist. Maybe you need to run psc-package init?"
-  mpkg <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile packageFile
-  case mpkg of
-    Nothing -> exitWithErr "Unable to parse psc-package.json"
-    Just pkg -> return pkg
-
-packageConfigToJSON :: PackageConfig -> Text
-packageConfigToJSON =
-    TL.toStrict
-    . TB.toLazyText
-    . encodePrettyToTextBuilder' config
-  where
-    config = defConfig
-               { confCompare =
-                   keyOrder [ "name"
-                            , "set"
-                            , "source"
-                            , "depends"
-                            ]
-               }
-
 packageSetToJSON :: PackageSet -> Text
 packageSetToJSON =
     TL.toStrict
@@ -83,11 +56,6 @@ packageSetToJSON =
   where
     config = defConfig { confCompare = compare }
 
-writePackageFile :: PackageConfig -> IO ()
-writePackageFile =
-  writeTextFile packageFile
-  . packageConfigToJSON
-
 type PackageSet = Map.Map PackageName PackageInfo
 
 cloneShallow
diff --git a/psc-package.cabal b/psc-package.cabal
index a62ef84..06357df 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -21,6 +21,8 @@ library
                          Language.PureScript.Package.Types.PackageName
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
+                         aeson-pretty -any,
+                         turtle ==1.3.*,
                          text
     default-language:    Haskell2010
 
diff --git a/src/Language/PureScript/Package/Types/PackageConfig.hs b/src/Language/PureScript/Package/Types/PackageConfig.hs
index 88ee8ca..4c6914a 100644
--- a/src/Language/PureScript/Package/Types/PackageConfig.hs
+++ b/src/Language/PureScript/Package/Types/PackageConfig.hs
@@ -2,17 +2,60 @@
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DeriveGeneric #-}
 
-module Language.PureScript.Package.Types.PackageConfig (PackageConfig(..)) where
+module Language.PureScript.Package.Types.PackageConfig (
+  PackageConfig(..)
+, readPackageFile
+, writePackageFile
+) where
 
 import           Data.Aeson (FromJSON, ToJSON)
+import qualified Data.Aeson as Aeson
+import qualified Data.Aeson.Encode.Pretty as AesonEncode
 import           Data.Text (Text)
+import           Data.Text.Encoding (encodeUtf8)
+import qualified Data.Text.Lazy as TL
+import qualified Data.Text.Lazy.Builder as TB
 import           GHC.Generics (Generic)
+import           Turtle
+import           Prelude hiding (FilePath)
 
 import           Language.PureScript.Package.Types.PackageName (PackageName)
 
 data PackageConfig = PackageConfig
   { name    :: PackageName
-  , depends :: [PackageName]
   , set     :: Text
   , source  :: Text
+  , depends :: [PackageName]
   } deriving (Show, Generic, FromJSON, ToJSON)
+
+packageConfigToJSON :: PackageConfig -> Text
+packageConfigToJSON =
+    TL.toStrict
+    . TB.toLazyText
+    . AesonEncode.encodePrettyToTextBuilder' config
+  where
+    config = AesonEncode.defConfig
+               { AesonEncode.confCompare =
+                   AesonEncode.keyOrder [ "name"
+                                        , "set"
+                                        , "source"
+                                        , "depends"
+                                        ]
+               }
+
+packageFile :: FilePath
+packageFile = "psc-package.json"
+
+readPackageFile :: IO PackageConfig
+readPackageFile = do
+  exists <- testfile packageFile
+  unless exists $ die "psc-package.json does not exist. Maybe you need to run psc-package init?"
+  mpkg <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile packageFile
+  case mpkg of
+    Nothing -> die "Unable to parse psc-package.json"
+    Just pkg -> return pkg
+
+writePackageFile :: PackageConfig -> IO ()
+writePackageFile =
+  writeTextFile packageFile
+  . packageConfigToJSON

From 53428cdb9eab2fbb0aa9143fc3c0492921f0833b Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 15:59:12 +0100
Subject: [PATCH 10/22] module for installOrUpdate

Moved several support functions to their own modules as well.
---
 app/Main.hs                                | 46 ++--------------------
 psc-package.cabal                          |  7 +++-
 src/Language/PureScript/Package/Git.hs     | 42 ++++++++++++++++++++
 src/Language/PureScript/Package/Install.hs | 20 ++++++++++
 src/Language/PureScript/Package/Path.hs    |  7 ++++
 5 files changed, 77 insertions(+), 45 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Git.hs
 create mode 100644 src/Language/PureScript/Package/Install.hs
 create mode 100644 src/Language/PureScript/Package/Path.hs

diff --git a/app/Main.hs b/app/Main.hs
index eb19f9c..de7479f 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -37,6 +37,9 @@ import qualified Turtle
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
 import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import Language.PureScript.Package.Install (installOrUpdate)
+import Language.PureScript.Package.Path (pathToTextUnsafe)
+import Language.PureScript.Package.Git (cloneShallow, listRemoteTags)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -45,9 +48,6 @@ exitWithErr :: Text -> IO a
 exitWithErr errText = errT errText >> exit (ExitFailure 1)
   where errT = traverse Turtle.err . textToLines
 
-pathToTextUnsafe :: Turtle.FilePath -> Text
-pathToTextUnsafe = either (error "Path.toText failed") id . Path.toText
-
 packageSetToJSON :: PackageSet -> Text
 packageSetToJSON =
     TL.toStrict
@@ -58,37 +58,6 @@ packageSetToJSON =
 
 type PackageSet = Map.Map PackageName PackageInfo
 
-cloneShallow
-  :: Text
-  -- ^ repo
-  -> Text
-  -- ^ branch/tag
-  -> Turtle.FilePath
-  -- ^ target directory
-  -> IO ExitCode
-cloneShallow from ref into =
-  proc "git"
-       [ "clone"
-       , "-q"
-       , "-c", "advice.detachedHead=false"
-       , "--depth", "1"
-       , "-b", ref
-       , from
-       , pathToTextUnsafe into
-       ] empty .||. exit (ExitFailure 1)
-
-listRemoteTags
-  :: Text
-  -- ^ repo
-  -> Turtle.Shell Text
-listRemoteTags from = let gitProc = inproc "git"
-                                    [ "ls-remote"
-                                    , "-q"
-                                    , "-t"
-                                    , from
-                                    ] empty
-                      in lineToText <$> gitProc
-
 getPackageSet :: PackageConfig -> IO ()
 getPackageSet PackageConfig{ source, set } = do
   let pkgDir = ".psc-package" </> fromText set </> ".set"
@@ -110,15 +79,6 @@ writePackageSet PackageConfig{ set } =
   let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
   in writeTextFile dbFile . packageSetToJSON
 
-installOrUpdate :: Text -> PackageName -> PackageInfo -> IO Turtle.FilePath
-installOrUpdate set pkgName PackageInfo{ repo, version } = do
-  let pkgDir = ".psc-package" </> fromText set </> fromText (runPackageName pkgName) </> fromText version
-  exists <- testdir pkgDir
-  unless exists . void $ do
-    echoT ("Updating " <> runPackageName pkgName)
-    cloneShallow repo version pkgDir
-  pure pkgDir
-
 getTransitiveDeps :: PackageSet -> [PackageName] -> IO [(PackageName, PackageInfo)]
 getTransitiveDeps db deps =
     Map.toList . fold <$> traverse (go Set.empty) deps
diff --git a/psc-package.cabal b/psc-package.cabal
index 06357df..3d8d2c7 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -18,11 +18,14 @@ library
     ghc-options:         -Wall -fwarn-tabs -fwarn-incomplete-uni-patterns -fwarn-incomplete-record-updates -fwarn-identities
     exposed-modules:     Language.PureScript.Package.Types.PackageConfig,
                          Language.PureScript.Package.Types.PackageInfo,
-                         Language.PureScript.Package.Types.PackageName
+                         Language.PureScript.Package.Types.PackageName,
+                         Language.PureScript.Package.Git,
+                         Language.PureScript.Package.Install,
+                         Language.PureScript.Package.Path
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
                          aeson-pretty -any,
-                         turtle ==1.3.*,
+                         turtle == 1.3.*,
                          text
     default-language:    Haskell2010
 
diff --git a/src/Language/PureScript/Package/Git.hs b/src/Language/PureScript/Package/Git.hs
new file mode 100644
index 0000000..5657430
--- /dev/null
+++ b/src/Language/PureScript/Package/Git.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Language.PureScript.Package.Git (
+  cloneShallow
+, listRemoteTags
+) where
+
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Path (pathToTextUnsafe)
+
+cloneShallow
+  :: Text
+  -- ^ repo
+  -> Text
+  -- ^ branch/tag
+  -> Turtle.FilePath
+  -- ^ target directory
+  -> IO ExitCode
+cloneShallow from ref into =
+  proc "git"
+       [ "clone"
+       , "-q"
+       , "-c", "advice.detachedHead=false"
+       , "--depth", "1"
+       , "-b", ref
+       , from
+       , pathToTextUnsafe into
+       ] empty .||. exit (ExitFailure 1)
+
+listRemoteTags
+  :: Text
+  -- ^ repo
+  -> Turtle.Shell Text
+listRemoteTags from = let gitProc = inproc "git"
+                                    [ "ls-remote"
+                                    , "-q"
+                                    , "-t"
+                                    , from
+                                    ] empty
+                      in lineToText <$> gitProc
diff --git a/src/Language/PureScript/Package/Install.hs b/src/Language/PureScript/Package/Install.hs
new file mode 100644
index 0000000..a2576bd
--- /dev/null
+++ b/src/Language/PureScript/Package/Install.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NamedFieldPuns #-}
+
+module Language.PureScript.Package.Install (installOrUpdate) where
+
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
+import Language.PureScript.Package.Git (cloneShallow)
+
+installOrUpdate :: Text -> PackageName -> PackageInfo -> IO FilePath
+installOrUpdate set pkgName PackageInfo{ repo, version } = do
+  let pkgDir = ".psc-package" </> fromText set </> fromText (runPackageName pkgName) </> fromText version
+  exists <- testdir pkgDir
+  unless exists . void $ do
+    echo $ "Updating " <> unsafeTextToLine (runPackageName pkgName)
+    cloneShallow repo version pkgDir
+  pure pkgDir
diff --git a/src/Language/PureScript/Package/Path.hs b/src/Language/PureScript/Package/Path.hs
new file mode 100644
index 0000000..8f7e4d3
--- /dev/null
+++ b/src/Language/PureScript/Package/Path.hs
@@ -0,0 +1,7 @@
+module Language.PureScript.Package.Path (pathToTextUnsafe) where
+
+import Turtle (FilePath, Text, toText)
+import Prelude (either, error, id, (.))
+
+pathToTextUnsafe :: FilePath -> Text
+pathToTextUnsafe = either (error "FilePath.toText failed") id . toText

From 8103ed85624362ce3dd879aa44eea89f28b7d87e Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 18:01:14 +0100
Subject: [PATCH 11/22] PackageSet module

---
 app/Main.hs                                   | 39 +------------
 psc-package.cabal                             |  4 +-
 .../PureScript/Package/Types/PackageSet.hs    | 55 +++++++++++++++++++
 3 files changed, 59 insertions(+), 39 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Types/PackageSet.hs

diff --git a/app/Main.hs b/app/Main.hs
index de7479f..045db53 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -7,8 +7,6 @@ module Main where
 
 import qualified Control.Foldl as Foldl
 import           Control.Concurrent.Async (forConcurrently_)
-import qualified Data.Aeson as Aeson
-import           Data.Aeson.Encode.Pretty
 import           Data.Foldable (fold, for_, traverse_)
 import qualified Data.Graph as G
 import           Data.List (maximumBy, nub)
@@ -18,9 +16,6 @@ import           Data.Ord (comparing)
 import qualified Data.Set as Set
 import           Data.Text (pack)
 import qualified Data.Text as T
-import           Data.Text.Encoding (encodeUtf8)
-import qualified Data.Text.Lazy as TL
-import qualified Data.Text.Lazy.Builder as TB
 import qualified Data.Text.Read as TR
 import           Data.Traversable (for)
 import           Data.Version (Version(..), parseVersion, showVersion)
@@ -37,9 +32,10 @@ import qualified Turtle
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
 import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
+import Language.PureScript.Package.Types.PackageSet (PackageSet, getPackageSet, readPackageSet, writePackageSet)
 import Language.PureScript.Package.Install (installOrUpdate)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
-import Language.PureScript.Package.Git (cloneShallow, listRemoteTags)
+import Language.PureScript.Package.Git (listRemoteTags)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -48,37 +44,6 @@ exitWithErr :: Text -> IO a
 exitWithErr errText = errT errText >> exit (ExitFailure 1)
   where errT = traverse Turtle.err . textToLines
 
-packageSetToJSON :: PackageSet -> Text
-packageSetToJSON =
-    TL.toStrict
-    . TB.toLazyText
-    . encodePrettyToTextBuilder' config
-  where
-    config = defConfig { confCompare = compare }
-
-type PackageSet = Map.Map PackageName PackageInfo
-
-getPackageSet :: PackageConfig -> IO ()
-getPackageSet PackageConfig{ source, set } = do
-  let pkgDir = ".psc-package" </> fromText set </> ".set"
-  exists <- testdir pkgDir
-  unless exists . void $ cloneShallow source set pkgDir
-
-readPackageSet :: PackageConfig -> IO PackageSet
-readPackageSet PackageConfig{ set } = do
-  let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
-  exists <- testfile dbFile
-  unless exists $ exitWithErr $ format (fp%" does not exist") dbFile
-  mdb <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile dbFile
-  case mdb of
-    Nothing -> exitWithErr "Unable to parse packages.json"
-    Just db -> return db
-
-writePackageSet :: PackageConfig -> PackageSet -> IO ()
-writePackageSet PackageConfig{ set } =
-  let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
-  in writeTextFile dbFile . packageSetToJSON
-
 getTransitiveDeps :: PackageSet -> [PackageName] -> IO [(PackageName, PackageInfo)]
 getTransitiveDeps db deps =
     Map.toList . fold <$> traverse (go Set.empty) deps
diff --git a/psc-package.cabal b/psc-package.cabal
index 3d8d2c7..cf47741 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -19,12 +19,14 @@ library
     exposed-modules:     Language.PureScript.Package.Types.PackageConfig,
                          Language.PureScript.Package.Types.PackageInfo,
                          Language.PureScript.Package.Types.PackageName,
+                         Language.PureScript.Package.Types.PackageSet,
                          Language.PureScript.Package.Git,
                          Language.PureScript.Package.Install,
                          Language.PureScript.Package.Path
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
                          aeson-pretty -any,
+                         containers,
                          turtle == 1.3.*,
                          text
     default-language:    Haskell2010
@@ -32,8 +34,6 @@ library
 executable psc-package
     build-depends: psc-package,
                    base >=4 && <5,
-                   aeson -any,
-                   aeson-pretty -any,
                    async -any,
                    bytestring -any,
                    containers -any,
diff --git a/src/Language/PureScript/Package/Types/PackageSet.hs b/src/Language/PureScript/Package/Types/PackageSet.hs
new file mode 100644
index 0000000..ec19ddf
--- /dev/null
+++ b/src/Language/PureScript/Package/Types/PackageSet.hs
@@ -0,0 +1,55 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NamedFieldPuns #-}
+
+module Language.PureScript.Package.Types.PackageSet (
+  PackageSet
+, packageSetToJSON
+, getPackageSet
+, readPackageSet
+, writePackageSet
+) where
+
+import qualified Data.Aeson as Aeson
+import qualified Data.Aeson.Encode.Pretty as AesonEncode
+import           Data.Map (Map)
+import           Data.Text.Encoding (encodeUtf8)
+import qualified Data.Text.Lazy as TL
+import qualified Data.Text.Lazy.Builder as TB
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..))
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo)
+import Language.PureScript.Package.Types.PackageName (PackageName)
+import Language.PureScript.Package.Git (cloneShallow)
+
+type PackageSet = Map PackageName PackageInfo
+
+packageSetToJSON :: PackageSet -> Text
+packageSetToJSON =
+    TL.toStrict
+    . TB.toLazyText
+    . AesonEncode.encodePrettyToTextBuilder' config
+  where
+    config = AesonEncode.defConfig { AesonEncode.confCompare = compare }
+
+getPackageSet :: PackageConfig -> IO ()
+getPackageSet PackageConfig{ source, set } = do
+  let pkgDir = ".psc-package" </> fromText set </> ".set"
+  exists <- testdir pkgDir
+  unless exists . void $ cloneShallow source set pkgDir
+
+readPackageSet :: PackageConfig -> IO PackageSet
+readPackageSet PackageConfig{ set } = do
+  let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
+  exists <- testfile dbFile
+  unless exists $ die $ format (fp%" does not exist") dbFile
+  mdb <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile dbFile
+  case mdb of
+    Nothing -> die "Unable to parse packages.json"
+    Just db -> return db
+
+writePackageSet :: PackageConfig -> PackageSet -> IO ()
+writePackageSet PackageConfig{ set } =
+  let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
+  in writeTextFile dbFile . packageSetToJSON

From 95891f404163e1ca26adf5fd3d826ecdcd7d2a4c Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 18:22:30 +0100
Subject: [PATCH 12/22] Update module

---
 app/Main.hs                                   | 27 ++---------------
 psc-package.cabal                             |  5 ++--
 .../PureScript/Package/Types/PackageSet.hs    | 26 +++++++++++++++--
 src/Language/PureScript/Package/Update.hs     | 29 +++++++++++++++++++
 4 files changed, 57 insertions(+), 30 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Update.hs

diff --git a/app/Main.hs b/app/Main.hs
index 045db53..5bb434f 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -6,7 +6,6 @@
 module Main where
 
 import qualified Control.Foldl as Foldl
-import           Control.Concurrent.Async (forConcurrently_)
 import           Data.Foldable (fold, for_, traverse_)
 import qualified Data.Graph as G
 import           Data.List (maximumBy, nub)
@@ -32,10 +31,11 @@ import qualified Turtle
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
 import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
-import Language.PureScript.Package.Types.PackageSet (PackageSet, getPackageSet, readPackageSet, writePackageSet)
+import Language.PureScript.Package.Types.PackageSet (PackageSet, getPackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
 import Language.PureScript.Package.Install (installOrUpdate)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Git (listRemoteTags)
+import Language.PureScript.Package.Update (updateImpl)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -44,29 +44,6 @@ exitWithErr :: Text -> IO a
 exitWithErr errText = errT errText >> exit (ExitFailure 1)
   where errT = traverse Turtle.err . textToLines
 
-getTransitiveDeps :: PackageSet -> [PackageName] -> IO [(PackageName, PackageInfo)]
-getTransitiveDeps db deps =
-    Map.toList . fold <$> traverse (go Set.empty) deps
-  where
-    go seen pkg
-      | pkg `Set.member` seen =
-          exitWithErr ("Cycle in package dependencies at package " <> runPackageName pkg)
-      | otherwise =
-        case Map.lookup pkg db of
-          Nothing ->
-            exitWithErr ("Package " <> runPackageName pkg <> " does not exist in package set")
-          Just info@PackageInfo{ dependencies } -> do
-            m <- fold <$> traverse (go (Set.insert pkg seen)) dependencies
-            return (Map.insert pkg info m)
-
-updateImpl :: PackageConfig -> IO ()
-updateImpl config@PackageConfig{ depends } = do
-  getPackageSet config
-  db <- readPackageSet config
-  trans <- getTransitiveDeps db depends
-  echoT ("Updating " <> pack (show (length trans)) <> " packages...")
-  forConcurrently_ trans . uncurry $ installOrUpdate (set config)
-
 getPureScriptVersion :: IO Version
 getPureScriptVersion = do
   let pursProc = inproc "purs" [ "--version" ] empty
diff --git a/psc-package.cabal b/psc-package.cabal
index cf47741..d539fa8 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -22,10 +22,12 @@ library
                          Language.PureScript.Package.Types.PackageSet,
                          Language.PureScript.Package.Git,
                          Language.PureScript.Package.Install,
-                         Language.PureScript.Package.Path
+                         Language.PureScript.Package.Path,
+                         Language.PureScript.Package.Update
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
                          aeson-pretty -any,
+                         async -any,
                          containers,
                          turtle == 1.3.*,
                          text
@@ -34,7 +36,6 @@ library
 executable psc-package
     build-depends: psc-package,
                    base >=4 && <5,
-                   async -any,
                    bytestring -any,
                    containers -any,
                    foldl -any,
diff --git a/src/Language/PureScript/Package/Types/PackageSet.hs b/src/Language/PureScript/Package/Types/PackageSet.hs
index ec19ddf..f4eeca9 100644
--- a/src/Language/PureScript/Package/Types/PackageSet.hs
+++ b/src/Language/PureScript/Package/Types/PackageSet.hs
@@ -7,20 +7,24 @@ module Language.PureScript.Package.Types.PackageSet (
 , getPackageSet
 , readPackageSet
 , writePackageSet
+, getTransitiveDeps
 ) where
 
 import qualified Data.Aeson as Aeson
 import qualified Data.Aeson.Encode.Pretty as AesonEncode
+import           Data.Foldable (fold)
 import           Data.Map (Map)
+import qualified Data.Map as Map
+import qualified Data.Set as Set
 import           Data.Text.Encoding (encodeUtf8)
 import qualified Data.Text.Lazy as TL
 import qualified Data.Text.Lazy.Builder as TB
-import           Turtle
+import           Turtle hiding (fold)
 import           Prelude hiding (FilePath)
 
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..))
-import Language.PureScript.Package.Types.PackageInfo (PackageInfo)
-import Language.PureScript.Package.Types.PackageName (PackageName)
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
 import Language.PureScript.Package.Git (cloneShallow)
 
 type PackageSet = Map PackageName PackageInfo
@@ -53,3 +57,19 @@ writePackageSet :: PackageConfig -> PackageSet -> IO ()
 writePackageSet PackageConfig{ set } =
   let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
   in writeTextFile dbFile . packageSetToJSON
+
+getTransitiveDeps :: PackageSet -> [PackageName] -> IO [(PackageName, PackageInfo)]
+getTransitiveDeps db deps =
+    Map.toList . fold <$> traverse (go Set.empty) deps
+  where
+    go seen pkg
+      | pkg `Set.member` seen =
+          die $ "Cycle in package dependencies at package " <> runPackageName pkg
+      | otherwise =
+        case Map.lookup pkg db of
+          Nothing ->
+            die $ "Package " <> runPackageName pkg <> " does not exist in package set"
+          Just info@PackageInfo{ dependencies } -> do
+            m <- fold <$> traverse (go (Set.insert pkg seen)) dependencies
+            return (Map.insert pkg info m)
+
diff --git a/src/Language/PureScript/Package/Update.hs b/src/Language/PureScript/Package/Update.hs
new file mode 100644
index 0000000..4d3eea9
--- /dev/null
+++ b/src/Language/PureScript/Package/Update.hs
@@ -0,0 +1,29 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NamedFieldPuns #-}
+
+module Language.PureScript.Package.Update (updateImpl) where
+
+import           Control.Concurrent.Async (forConcurrently_)
+import qualified Data.Text as T
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..))
+import Language.PureScript.Package.Types.PackageSet (readPackageSet, getTransitiveDeps)
+import Language.PureScript.Package.Install (installOrUpdate)
+import Language.PureScript.Package.Git (cloneShallow)
+
+updateImpl :: PackageConfig -> IO ()
+updateImpl config@PackageConfig{ depends } = do
+  getPackageSet config
+  db <- readPackageSet config
+  trans <- getTransitiveDeps db depends
+  echo ("Updating " <> unsafeTextToLine (T.pack (show (length trans))) <> " packages...")
+  forConcurrently_ trans . uncurry $ installOrUpdate (set config)
+
+  where
+  getPackageSet :: PackageConfig -> IO ()
+  getPackageSet PackageConfig{ source, set } = do
+    let pkgDir = ".psc-package" </> fromText set </> ".set"
+    exists <- testdir pkgDir
+    unless exists . void $ cloneShallow source set pkgDir

From 18f3c3284be2725e083c23ba77df10c3b67cb7bd Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 18:45:04 +0100
Subject: [PATCH 13/22] Initialize module

---
 app/Main.hs                                   | 53 ++---------------
 psc-package.cabal                             |  2 +
 src/Language/PureScript/Package/Initialize.hs | 58 +++++++++++++++++++
 3 files changed, 65 insertions(+), 48 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Initialize.hs

diff --git a/app/Main.hs b/app/Main.hs
index 5bb434f..6c3b7b0 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -8,30 +8,28 @@ module Main where
 import qualified Control.Foldl as Foldl
 import           Data.Foldable (fold, for_, traverse_)
 import qualified Data.Graph as G
-import           Data.List (maximumBy, nub)
+import           Data.List (nub)
 import qualified Data.Map as Map
 import           Data.Maybe (fromMaybe, mapMaybe)
-import           Data.Ord (comparing)
-import qualified Data.Set as Set
 import           Data.Text (pack)
 import qualified Data.Text as T
 import qualified Data.Text.Read as TR
 import           Data.Traversable (for)
-import           Data.Version (Version(..), parseVersion, showVersion)
+import           Data.Version (showVersion)
 import qualified Filesystem.Path.CurrentOS as Path
 import qualified Options.Applicative as Opts
 import qualified Paths_psc_package as Paths
 import           System.Environment (getArgs)
 import qualified System.IO as IO
 import qualified System.Process as Process
-import qualified Text.ParserCombinators.ReadP as Read
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
-import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName, untitledPackageName, preludePackageName)
-import Language.PureScript.Package.Types.PackageSet (PackageSet, getPackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
+import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName)
+import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
+import Language.PureScript.Package.Initialize (initialize)
 import Language.PureScript.Package.Install (installOrUpdate)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Git (listRemoteTags)
@@ -44,47 +42,6 @@ exitWithErr :: Text -> IO a
 exitWithErr errText = errT errText >> exit (ExitFailure 1)
   where errT = traverse Turtle.err . textToLines
 
-getPureScriptVersion :: IO Version
-getPureScriptVersion = do
-  let pursProc = inproc "purs" [ "--version" ] empty
-  outputLines <- Turtle.fold (fmap lineToText pursProc) Foldl.list
-  case outputLines of
-    [onlyLine]
-      | results@(_ : _) <- Read.readP_to_S parseVersion (T.unpack onlyLine) ->
-           pure (fst (maximumBy (comparing (length . versionBranch . fst)) results))
-      | otherwise -> exitWithErr "Unable to parse output of purs --version"
-    _ -> exitWithErr "Unexpected output from purs --version"
-
-initialize :: Maybe (Text, Maybe Text) -> IO ()
-initialize setAndSource = do
-    exists <- testfile "psc-package.json"
-    when exists $ exitWithErr "psc-package.json already exists"
-    echoT "Initializing new project in current directory"
-    pkgName <- packageNameFromPWD . pathToTextUnsafe . Path.filename <$> pwd
-    pkg <- case setAndSource of
-      Nothing -> do
-        pursVersion <- getPureScriptVersion
-        echoT ("Using the default package set for PureScript compiler version " <>
-          fromString (showVersion pursVersion))
-        echoT "(Use --source / --set to override this behavior)"
-        pure PackageConfig { name    = pkgName
-                           , depends = [ preludePackageName ]
-                           , source  = "https://github.com/purescript/package-sets.git"
-                           , set     = "psc-" <> pack (showVersion pursVersion)
-                           }
-      Just (set, source) ->
-        pure PackageConfig { name    = pkgName
-                           , depends = [ preludePackageName ]
-                           , source  = fromMaybe "https://github.com/purescript/package-sets.git" source
-                           , set
-                           }
-
-    writePackageFile pkg
-    updateImpl pkg
-  where
-    packageNameFromPWD =
-      either (const untitledPackageName) id . mkPackageName
-
 update :: IO ()
 update = do
   pkg <- readPackageFile
diff --git a/psc-package.cabal b/psc-package.cabal
index d539fa8..54902ca 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -21,6 +21,7 @@ library
                          Language.PureScript.Package.Types.PackageName,
                          Language.PureScript.Package.Types.PackageSet,
                          Language.PureScript.Package.Git,
+                         Language.PureScript.Package.Initialize,
                          Language.PureScript.Package.Install,
                          Language.PureScript.Package.Path,
                          Language.PureScript.Package.Update
@@ -29,6 +30,7 @@ library
                          aeson-pretty -any,
                          async -any,
                          containers,
+                         foldl -any,
                          turtle == 1.3.*,
                          text
     default-language:    Haskell2010
diff --git a/src/Language/PureScript/Package/Initialize.hs b/src/Language/PureScript/Package/Initialize.hs
new file mode 100644
index 0000000..3ea6d8a
--- /dev/null
+++ b/src/Language/PureScript/Package/Initialize.hs
@@ -0,0 +1,58 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Language.PureScript.Package.Initialize (initialize) where
+
+import qualified Control.Foldl as Foldl
+import           Data.List (maximumBy)
+import           Data.Maybe (fromMaybe)
+import           Data.Ord (comparing)
+import qualified Data.Text as T
+import           Data.Version (Version(..), parseVersion, showVersion)
+import           Text.ParserCombinators.ReadP (readP_to_S)
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, writePackageFile)
+import Language.PureScript.Package.Types.PackageName (untitledPackageName, mkPackageName, preludePackageName)
+import Language.PureScript.Package.Path (pathToTextUnsafe)
+import Language.PureScript.Package.Update (updateImpl)
+
+initialize :: Maybe (Text, Maybe Text) -> IO ()
+initialize setAndSource = do
+    exists <- testfile "psc-package.json"
+    when exists $ die "psc-package.json already exists"
+    echo "Initializing new project in current directory"
+    pkgName <- packageNameFromPWD . pathToTextUnsafe . filename <$> pwd
+    pkg <- case setAndSource of
+      Nothing -> do
+        pursVersion <- getPureScriptVersion
+        echo ("Using the default package set for PureScript compiler version " <>
+          unsafeTextToLine (fromString (showVersion pursVersion)))
+        echo "(Use --source / --set to override this behavior)"
+        pure PackageConfig { name    = pkgName
+                           , depends = [ preludePackageName ]
+                           , source  = defaultSource
+                           , set     = "psc-" <> T.pack (showVersion pursVersion)
+                           }
+      Just (set, source) ->
+        pure PackageConfig { name    = pkgName
+                           , depends = [ preludePackageName ]
+                           , source  = fromMaybe defaultSource source
+                           , set
+                           }
+
+    writePackageFile pkg
+    updateImpl pkg
+  where
+    defaultSource = "https://github.com/purescript/package-sets.git"
+    packageNameFromPWD = either (const untitledPackageName) id . mkPackageName
+    getPureScriptVersion = do
+      let pursProc = inproc "purs" [ "--version" ] empty
+      outputLines <- Turtle.fold (fmap lineToText pursProc) Foldl.list
+      case outputLines of
+        [onlyLine]
+          | results@(_ : _) <- readP_to_S parseVersion (T.unpack onlyLine) ->
+               pure (fst (maximumBy (comparing (length . versionBranch . fst)) results))
+          | otherwise -> die "Unable to parse output of purs --version"
+        _ -> die "Unexpected output from purs --version"

From f72a597e8e1de0ffab923d83953b3c0533c8a824 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 18:50:03 +0100
Subject: [PATCH 14/22] replace exitWithErr with die

---
 app/Main.hs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index 6c3b7b0..e6b5a83 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -38,10 +38,6 @@ import Language.PureScript.Package.Update (updateImpl)
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
 
-exitWithErr :: Text -> IO a
-exitWithErr errText = errT errText >> exit (ExitFailure 1)
-  where errT = traverse Turtle.err . textToLines
-
 update :: IO ()
 update = do
   pkg <- readPackageFile
@@ -73,7 +69,7 @@ packageNameFromString str =
   case mkPackageName (pack str) of
     Right pkgName ->
       pure pkgName
-    Left _ -> exitWithErr $ "Invalid package name: " <> pack (show str)
+    Left _ -> die $ "Invalid package name: " <> pack (show str)
 
 listDependencies :: IO ()
 listDependencies = do

From a7d0b32f909edbd2c01334fabc92dc36949b6c43 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 19:10:47 +0100
Subject: [PATCH 15/22] move appropriate functions into Update module

---
 app/Main.hs                                   | 35 +++----------------
 src/Language/PureScript/Package/Install.hs    | 24 ++++++-------
 .../PureScript/Package/Types/PackageName.hs   |  8 +++++
 src/Language/PureScript/Package/Update.hs     | 33 +++++++++++++++--
 4 files changed, 53 insertions(+), 47 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index e6b5a83..5385acd 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -8,7 +8,6 @@ module Main where
 import qualified Control.Foldl as Foldl
 import           Data.Foldable (fold, for_, traverse_)
 import qualified Data.Graph as G
-import           Data.List (nub)
 import qualified Data.Map as Map
 import           Data.Maybe (fromMaybe, mapMaybe)
 import           Data.Text (pack)
@@ -25,32 +24,19 @@ import qualified System.Process as Process
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile, writePackageFile)
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
-import Language.PureScript.Package.Types.PackageName (PackageName, mkPackageName, runPackageName)
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName, packageNameFromString)
 import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
 import Language.PureScript.Package.Initialize (initialize)
-import Language.PureScript.Package.Install (installOrUpdate)
+import Language.PureScript.Package.Install (install)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Git (listRemoteTags)
-import Language.PureScript.Package.Update (updateImpl)
+import Language.PureScript.Package.Update (update, updateImpl, installOrUpdate, updateAndWritePackageFile)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
 
-update :: IO ()
-update = do
-  pkg <- readPackageFile
-  updateImpl pkg
-  echoT "Update complete"
-
-install :: String -> IO ()
-install pkgName' = do
-  pkg <- readPackageFile
-  pkgName <- packageNameFromString pkgName'
-  let pkg' = pkg { depends = nub (pkgName : depends pkg) }
-  updateAndWritePackageFile pkg'
-
 uninstall :: String -> IO ()
 uninstall pkgName' = do
   pkg <- readPackageFile
@@ -58,19 +44,6 @@ uninstall pkgName' = do
   let pkg' = pkg { depends = filter (/= pkgName) $ depends pkg }
   updateAndWritePackageFile pkg'
 
-updateAndWritePackageFile :: PackageConfig -> IO ()
-updateAndWritePackageFile pkg = do
-  updateImpl pkg
-  writePackageFile pkg
-  echoT "psc-package.json file was updated"
-
-packageNameFromString :: String -> IO PackageName
-packageNameFromString str =
-  case mkPackageName (pack str) of
-    Right pkgName ->
-      pure pkgName
-    Left _ -> die $ "Invalid package name: " <> pack (show str)
-
 listDependencies :: IO ()
 listDependencies = do
   pkg@PackageConfig{ depends } <- readPackageFile
diff --git a/src/Language/PureScript/Package/Install.hs b/src/Language/PureScript/Package/Install.hs
index a2576bd..c123e2b 100644
--- a/src/Language/PureScript/Package/Install.hs
+++ b/src/Language/PureScript/Package/Install.hs
@@ -1,20 +1,18 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE NamedFieldPuns #-}
 
-module Language.PureScript.Package.Install (installOrUpdate) where
+module Language.PureScript.Package.Install (install) where
 
-import           Turtle
+import           Data.List (nub)
 import           Prelude hiding (FilePath)
 
-import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
-import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
-import Language.PureScript.Package.Git (cloneShallow)
+import Language.PureScript.Package.Types.PackageConfig (readPackageFile, depends)
+import Language.PureScript.Package.Types.PackageName (packageNameFromString)
+import Language.PureScript.Package.Update (updateAndWritePackageFile)
 
-installOrUpdate :: Text -> PackageName -> PackageInfo -> IO FilePath
-installOrUpdate set pkgName PackageInfo{ repo, version } = do
-  let pkgDir = ".psc-package" </> fromText set </> fromText (runPackageName pkgName) </> fromText version
-  exists <- testdir pkgDir
-  unless exists . void $ do
-    echo $ "Updating " <> unsafeTextToLine (runPackageName pkgName)
-    cloneShallow repo version pkgDir
-  pure pkgDir
+install :: String -> IO ()
+install pkgName' = do
+  pkg <- readPackageFile
+  pkgName <- packageNameFromString pkgName'
+  let pkg' = pkg { depends = nub (pkgName : depends pkg) } -- TODO: ordnub
+  updateAndWritePackageFile pkg'
diff --git a/src/Language/PureScript/Package/Types/PackageName.hs b/src/Language/PureScript/Package/Types/PackageName.hs
index 0075a2e..30de9c0 100644
--- a/src/Language/PureScript/Package/Types/PackageName.hs
+++ b/src/Language/PureScript/Package/Types/PackageName.hs
@@ -4,6 +4,7 @@ module Language.PureScript.Package.Types.PackageName
   ( PackageName
   , mkPackageName
   , runPackageName
+  , packageNameFromString
   , preludePackageName
   , untitledPackageName
   ) where
@@ -15,6 +16,7 @@ import           Data.Char (isAscii, isLower, isDigit)
 import           Data.Monoid ((<>))
 import           Data.Text (Text)
 import qualified Data.Text as T
+import           Turtle (die)
 
 newtype PackageName
   = PackageName Text
@@ -78,6 +80,12 @@ mkPackageName = fmap PackageName . validateAll validators
 runPackageName :: PackageName -> Text
 runPackageName (PackageName t) = t
 
+packageNameFromString :: String -> IO PackageName
+packageNameFromString str =
+  case mkPackageName (T.pack str) of
+    Right pkgName -> pure pkgName
+    Left _ -> die $ "Invalid package name: " <> T.pack (show str)
+
 preludePackageName :: PackageName
 preludePackageName = PackageName "prelude"
 
diff --git a/src/Language/PureScript/Package/Update.hs b/src/Language/PureScript/Package/Update.hs
index 4d3eea9..183057d 100644
--- a/src/Language/PureScript/Package/Update.hs
+++ b/src/Language/PureScript/Package/Update.hs
@@ -1,18 +1,30 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE NamedFieldPuns #-}
 
-module Language.PureScript.Package.Update (updateImpl) where
+module Language.PureScript.Package.Update (
+  update
+, updateImpl
+, updateAndWritePackageFile
+, installOrUpdate
+) where
 
 import           Control.Concurrent.Async (forConcurrently_)
 import qualified Data.Text as T
 import           Turtle
 import           Prelude hiding (FilePath)
 
-import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..))
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), readPackageFile, writePackageFile)
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
 import Language.PureScript.Package.Types.PackageSet (readPackageSet, getTransitiveDeps)
-import Language.PureScript.Package.Install (installOrUpdate)
 import Language.PureScript.Package.Git (cloneShallow)
 
+update :: IO ()
+update = do
+  pkg <- readPackageFile
+  updateImpl pkg
+  echo "Update complete"
+
 updateImpl :: PackageConfig -> IO ()
 updateImpl config@PackageConfig{ depends } = do
   getPackageSet config
@@ -27,3 +39,18 @@ updateImpl config@PackageConfig{ depends } = do
     let pkgDir = ".psc-package" </> fromText set </> ".set"
     exists <- testdir pkgDir
     unless exists . void $ cloneShallow source set pkgDir
+
+updateAndWritePackageFile :: PackageConfig -> IO ()
+updateAndWritePackageFile pkg = do
+  updateImpl pkg
+  writePackageFile pkg
+  echo "psc-package.json file was updated"
+
+installOrUpdate :: Text -> PackageName -> PackageInfo -> IO FilePath
+installOrUpdate set pkgName PackageInfo{ repo, version } = do
+  let pkgDir = ".psc-package" </> fromText set </> fromText (runPackageName pkgName) </> fromText version
+  exists <- testdir pkgDir
+  unless exists . void $ do
+    echo $ "Updating " <> unsafeTextToLine (runPackageName pkgName)
+    cloneShallow repo version pkgDir
+  pure pkgDir

From d0c931f6d750cb563d0d62239414d8f191b1bf5c Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 19:21:26 +0100
Subject: [PATCH 16/22] Uninstall module

---
 app/Main.hs                                  | 12 +++---------
 psc-package.cabal                            |  1 +
 src/Language/PureScript/Package/Uninstall.hs | 12 ++++++++++++
 3 files changed, 16 insertions(+), 9 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Uninstall.hs

diff --git a/app/Main.hs b/app/Main.hs
index 5385acd..94f49cb 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -26,24 +26,18 @@ import qualified Turtle
 
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
-import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName, packageNameFromString)
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
 import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
 import Language.PureScript.Package.Initialize (initialize)
 import Language.PureScript.Package.Install (install)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Git (listRemoteTags)
-import Language.PureScript.Package.Update (update, updateImpl, installOrUpdate, updateAndWritePackageFile)
+import Language.PureScript.Package.Uninstall (uninstall)
+import Language.PureScript.Package.Update (update, updateImpl, installOrUpdate)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
 
-uninstall :: String -> IO ()
-uninstall pkgName' = do
-  pkg <- readPackageFile
-  pkgName <- packageNameFromString pkgName'
-  let pkg' = pkg { depends = filter (/= pkgName) $ depends pkg }
-  updateAndWritePackageFile pkg'
-
 listDependencies :: IO ()
 listDependencies = do
   pkg@PackageConfig{ depends } <- readPackageFile
diff --git a/psc-package.cabal b/psc-package.cabal
index 54902ca..6bc2784 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -24,6 +24,7 @@ library
                          Language.PureScript.Package.Initialize,
                          Language.PureScript.Package.Install,
                          Language.PureScript.Package.Path,
+                         Language.PureScript.Package.Uninstall,
                          Language.PureScript.Package.Update
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
diff --git a/src/Language/PureScript/Package/Uninstall.hs b/src/Language/PureScript/Package/Uninstall.hs
new file mode 100644
index 0000000..9852c1f
--- /dev/null
+++ b/src/Language/PureScript/Package/Uninstall.hs
@@ -0,0 +1,12 @@
+module Language.PureScript.Package.Uninstall (uninstall) where
+
+import Language.PureScript.Package.Types.PackageConfig (readPackageFile, depends)
+import Language.PureScript.Package.Types.PackageName (packageNameFromString)
+import Language.PureScript.Package.Update (updateAndWritePackageFile)
+
+uninstall :: String -> IO ()
+uninstall pkgName' = do
+  pkg <- readPackageFile
+  pkgName <- packageNameFromString pkgName'
+  let pkg' = pkg { depends = filter (/= pkgName) $ depends pkg }
+  updateAndWritePackageFile pkg'

From 777ffba2dd5b8d391f283afbbefb3153bb57f3b9 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 19:32:35 +0100
Subject: [PATCH 17/22] Verify module

---
 app/Main.hs                               | 26 +++-------------
 psc-package.cabal                         |  3 +-
 src/Language/PureScript/Package/Verify.hs | 37 +++++++++++++++++++++++
 3 files changed, 43 insertions(+), 23 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Verify.hs

diff --git a/app/Main.hs b/app/Main.hs
index 94f49cb..570b242 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,15 +1,14 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE TupleSections #-}
 
 module Main where
 
 import qualified Control.Foldl as Foldl
-import           Data.Foldable (fold, for_, traverse_)
+import           Data.Foldable (fold, traverse_)
 import qualified Data.Graph as G
 import qualified Data.Map as Map
-import           Data.Maybe (fromMaybe, mapMaybe)
+import           Data.Maybe (mapMaybe)
 import           Data.Text (pack)
 import qualified Data.Text as T
 import qualified Data.Text.Read as TR
@@ -33,7 +32,8 @@ import Language.PureScript.Package.Install (install)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Git (listRemoteTags)
 import Language.PureScript.Package.Uninstall (uninstall)
-import Language.PureScript.Package.Update (update, updateImpl, installOrUpdate)
+import Language.PureScript.Package.Update (update, updateImpl)
+import Language.PureScript.Package.Verify (verifyPackageSet)
 
 echoT :: Text -> IO ()
 echoT = Turtle.printf (Turtle.s % "\n")
@@ -189,24 +189,6 @@ checkForUpdates applyMinorUpdates applyMajorUpdates = do
     isMinorReleaseFrom (x : xs) (y : ys) = y == x && ys > xs
     isMinorReleaseFrom _        _        = False
 
-verifyPackageSet :: IO ()
-verifyPackageSet = do
-  pkg <- readPackageFile
-  db <- readPackageSet pkg
-
-  echoT ("Verifying " <> pack (show (Map.size db)) <> " packages.")
-  echoT "Warning: this could take some time!"
-
-  let installOrUpdate' (name, pkgInfo) = (name, ) <$> installOrUpdate (set pkg) name pkgInfo
-  paths <- Map.fromList <$> traverse installOrUpdate' (Map.toList db)
-
-  for_ (Map.toList db) $ \(name, _) -> do
-    let dirFor pkgName = fromMaybe (error ("verifyPackageSet: no directory for " <> show pkgName)) (Map.lookup pkgName paths)
-    echoT ("Verifying package " <> runPackageName name)
-    dependencies <- map fst <$> getTransitiveDeps db [name]
-    let srcGlobs = map (pathToTextUnsafe . (</> ("src" </> "**" </> "*.purs")) . dirFor) dependencies
-    procs "purs" ("compile" : srcGlobs) empty
-
 main :: IO ()
 main = do
     IO.hSetEncoding IO.stdout IO.utf8
diff --git a/psc-package.cabal b/psc-package.cabal
index 6bc2784..42928ac 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -25,7 +25,8 @@ library
                          Language.PureScript.Package.Install,
                          Language.PureScript.Package.Path,
                          Language.PureScript.Package.Uninstall,
-                         Language.PureScript.Package.Update
+                         Language.PureScript.Package.Update,
+                         Language.PureScript.Package.Verify
     build-depends:       base >= 4.7 && < 5,
                          aeson -any,
                          aeson-pretty -any,
diff --git a/src/Language/PureScript/Package/Verify.hs b/src/Language/PureScript/Package/Verify.hs
new file mode 100644
index 0000000..6cf2014
--- /dev/null
+++ b/src/Language/PureScript/Package/Verify.hs
@@ -0,0 +1,37 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TupleSections #-}
+
+module Language.PureScript.Package.Verify (verifyPackageSet) where
+
+import           Data.Foldable (for_)
+import qualified Data.Map as Map
+import           Data.Maybe (fromMaybe)
+import qualified Data.Text as T
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageConfig (readPackageFile, set)
+import Language.PureScript.Package.Types.PackageName (runPackageName)
+import Language.PureScript.Package.Types.PackageSet (readPackageSet, getTransitiveDeps)
+import Language.PureScript.Package.Path (pathToTextUnsafe)
+import Language.PureScript.Package.Update (installOrUpdate)
+
+verifyPackageSet :: IO ()
+verifyPackageSet = do
+  pkg <- readPackageFile
+  db <- readPackageSet pkg
+
+  echo $
+    "Verifying " <> unsafeTextToLine (T.pack (show (Map.size db))) <> " packages."
+  echo "Warning: this could take some time!"
+
+  let installOrUpdate' (name, pkgInfo) = (name, ) <$> installOrUpdate (set pkg) name pkgInfo
+  paths <- Map.fromList <$> traverse installOrUpdate' (Map.toList db)
+
+  for_ (Map.toList db) $ \(name, _) -> do
+    let dirFor pkgName = fromMaybe (error ("verifyPackageSet: no directory for " <> show pkgName)) (Map.lookup pkgName paths)
+    echo $ "Verifying package " <> unsafeTextToLine (runPackageName name)
+    dependencies <- map fst <$> getTransitiveDeps db [name]
+    let srcGlobs = map (pathToTextUnsafe . (</> ("src" </> "**" </> "*.purs")) . dirFor) dependencies
+    procs "purs" ("compile" : srcGlobs) empty
+

From 840405e2ef5e0a8d44df98b62e618a0f85eb9e90 Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Thu, 10 Aug 2017 22:59:32 +0100
Subject: [PATCH 18/22] Paths module

---
 app/Main.hs                              | 24 +++---------------
 psc-package.cabal                        |  1 +
 src/Language/PureScript/Package/Paths.hs | 32 ++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 21 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Paths.hs

diff --git a/app/Main.hs b/app/Main.hs
index 570b242..e6ca05c 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 
 module Main where
 
@@ -23,13 +22,14 @@ import qualified System.Process as Process
 import           Turtle hiding (echo, fold, s, x)
 import qualified Turtle
 
-import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, readPackageFile)
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), depends, readPackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..), repo, version, dependencies)
 import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
-import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, writePackageSet, getTransitiveDeps)
+import Language.PureScript.Package.Types.PackageSet (readPackageSet, writePackageSet, getTransitiveDeps)
 import Language.PureScript.Package.Initialize (initialize)
 import Language.PureScript.Package.Install (install)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
+import Language.PureScript.Package.Paths (getPaths)
 import Language.PureScript.Package.Git (listRemoteTags)
 import Language.PureScript.Package.Uninstall (uninstall)
 import Language.PureScript.Package.Update (update, updateImpl)
@@ -65,24 +65,6 @@ listPackages sorted = do
     vs = G.topSort (G.transposeG gr)
     fromNode (pkg, name, _) = (name, pkg)
 
-getSourcePaths :: PackageConfig -> PackageSet -> [PackageName] -> IO [Turtle.FilePath]
-getSourcePaths PackageConfig{..} db pkgNames = do
-  trans <- getTransitiveDeps db pkgNames
-  let paths = [ ".psc-package"
-                </> fromText set
-                </> fromText (runPackageName pkgName)
-                </> fromText version
-                </> "src" </> "**" </> "*.purs"
-              | (pkgName, PackageInfo{ version }) <- trans
-              ]
-  return paths
-
-getPaths :: IO [Turtle.FilePath]
-getPaths = do
-  pkg@PackageConfig{..} <- readPackageFile
-  db <- readPackageSet pkg
-  getSourcePaths pkg db depends
-
 listSourcePaths :: IO ()
 listSourcePaths = do
   paths <- getPaths
diff --git a/psc-package.cabal b/psc-package.cabal
index 42928ac..3162cdf 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -24,6 +24,7 @@ library
                          Language.PureScript.Package.Initialize,
                          Language.PureScript.Package.Install,
                          Language.PureScript.Package.Path,
+                         Language.PureScript.Package.Paths,
                          Language.PureScript.Package.Uninstall,
                          Language.PureScript.Package.Update,
                          Language.PureScript.Package.Verify
diff --git a/src/Language/PureScript/Package/Paths.hs b/src/Language/PureScript/Package/Paths.hs
new file mode 100644
index 0000000..c847f7b
--- /dev/null
+++ b/src/Language/PureScript/Package/Paths.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module Language.PureScript.Package.Paths (getPaths) where
+
+import           Turtle
+import           Prelude hiding (FilePath)
+
+import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), readPackageFile)
+import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
+import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
+import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, getTransitiveDeps)
+
+getPaths :: IO [FilePath]
+getPaths = do
+  pkg@PackageConfig{..} <- readPackageFile
+  db <- readPackageSet pkg
+  getSourcePaths pkg db depends
+  where
+  getSourcePaths :: PackageConfig -> PackageSet -> [PackageName] -> IO [FilePath]
+  getSourcePaths PackageConfig{..} db pkgNames = do
+    trans <- getTransitiveDeps db pkgNames
+    let paths = [ ".psc-package"
+                  </> fromText set
+                  </> fromText (runPackageName pkgName)
+                  </> fromText version
+                  </> "src" </> "**" </> "*.purs"
+                | (pkgName, PackageInfo{ version }) <- trans
+                ]
+    return paths
+

From f24b5a0a6972bccf4eb097d0887ecd8ab1ca749c Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Fri, 11 Aug 2017 12:33:16 +0100
Subject: [PATCH 19/22] create a monad for logging with `echo`

This allows library users to silence output to stdout by using
`SilentT`, without requiring much change to the codebase.
---
 psc-package.cabal                             |  6 ++-
 src/Language/PureScript/Package/Echo.hs       | 40 +++++++++++++++++++
 src/Language/PureScript/Package/Git.hs        |  5 ++-
 src/Language/PureScript/Package/Initialize.hs |  9 +++--
 .../PureScript/Package/Types/PackageConfig.hs | 10 ++---
 .../PureScript/Package/Types/PackageSet.hs    | 12 ++++--
 src/Language/PureScript/Package/Update.hs     | 21 +++++-----
 src/Language/PureScript/Package/Verify.hs     | 11 ++---
 8 files changed, 81 insertions(+), 33 deletions(-)
 create mode 100644 src/Language/PureScript/Package/Echo.hs

diff --git a/psc-package.cabal b/psc-package.cabal
index 3162cdf..7b74030 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -20,6 +20,7 @@ library
                          Language.PureScript.Package.Types.PackageInfo,
                          Language.PureScript.Package.Types.PackageName,
                          Language.PureScript.Package.Types.PackageSet,
+                         Language.PureScript.Package.Echo,
                          Language.PureScript.Package.Git,
                          Language.PureScript.Package.Initialize,
                          Language.PureScript.Package.Install,
@@ -34,8 +35,9 @@ library
                          async -any,
                          containers,
                          foldl -any,
-                         turtle == 1.3.*,
-                         text
+                         text -any,
+                         transformers -any,
+                         turtle == 1.3.*
     default-language:    Haskell2010
 
 executable psc-package
diff --git a/src/Language/PureScript/Package/Echo.hs b/src/Language/PureScript/Package/Echo.hs
new file mode 100644
index 0000000..e3d31ae
--- /dev/null
+++ b/src/Language/PureScript/Package/Echo.hs
@@ -0,0 +1,40 @@
+module Language.PureScript.Package.Echo (
+  MonadEcho(..)
+, SilentT(..)
+) where
+
+import Control.Monad.IO.Class (MonadIO, liftIO)
+import Control.Monad.Trans.Class (MonadTrans, lift)
+import Data.Text (Text)
+import Data.Text.IO (putStrLn)
+import Prelude hiding (putStrLn)
+
+class Applicative m => MonadEcho m where
+  echo :: Text -> m ()
+instance MonadEcho IO where
+  echo = putStrLn
+
+newtype SilentT m a = SilentT { runSilentT :: m a }
+
+instance Functor m => Functor (SilentT m) where
+    fmap f = SilentT . fmap f . runSilentT
+    {-# INLINE fmap #-}
+
+instance Applicative m => Applicative (SilentT m) where
+    pure = SilentT . pure
+    {-# INLINE pure #-}
+    f <*> a = SilentT (runSilentT f <*> runSilentT a)
+    {-# INLINE (<*>) #-}
+
+instance Monad m => Monad (SilentT m) where
+  return = SilentT . return
+  SilentT ma >>= f = SilentT $ ma >>= runSilentT . f
+
+instance MonadIO m => MonadIO (SilentT m) where
+  liftIO = lift . liftIO
+
+instance Applicative m => MonadEcho (SilentT m) where
+  echo = const . SilentT $ pure ()
+
+instance MonadTrans SilentT where
+  lift = SilentT
diff --git a/src/Language/PureScript/Package/Git.hs b/src/Language/PureScript/Package/Git.hs
index 5657430..85fcb4c 100644
--- a/src/Language/PureScript/Package/Git.hs
+++ b/src/Language/PureScript/Package/Git.hs
@@ -11,13 +11,14 @@ import           Prelude hiding (FilePath)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 
 cloneShallow
-  :: Text
+  :: MonadIO m
+  => Text
   -- ^ repo
   -> Text
   -- ^ branch/tag
   -> Turtle.FilePath
   -- ^ target directory
-  -> IO ExitCode
+  -> m ExitCode
 cloneShallow from ref into =
   proc "git"
        [ "clone"
diff --git a/src/Language/PureScript/Package/Initialize.hs b/src/Language/PureScript/Package/Initialize.hs
index 3ea6d8a..eccdbb2 100644
--- a/src/Language/PureScript/Package/Initialize.hs
+++ b/src/Language/PureScript/Package/Initialize.hs
@@ -10,15 +10,16 @@ import           Data.Ord (comparing)
 import qualified Data.Text as T
 import           Data.Version (Version(..), parseVersion, showVersion)
 import           Text.ParserCombinators.ReadP (readP_to_S)
-import           Turtle
+import           Turtle hiding (echo)
 import           Prelude hiding (FilePath)
 
+import Language.PureScript.Package.Echo (MonadEcho(..), echo)
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), name, depends, set, source, writePackageFile)
 import Language.PureScript.Package.Types.PackageName (untitledPackageName, mkPackageName, preludePackageName)
 import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Update (updateImpl)
 
-initialize :: Maybe (Text, Maybe Text) -> IO ()
+initialize :: (MonadIO m, MonadEcho m) => Maybe (Text, Maybe Text) -> m ()
 initialize setAndSource = do
     exists <- testfile "psc-package.json"
     when exists $ die "psc-package.json already exists"
@@ -27,8 +28,8 @@ initialize setAndSource = do
     pkg <- case setAndSource of
       Nothing -> do
         pursVersion <- getPureScriptVersion
-        echo ("Using the default package set for PureScript compiler version " <>
-          unsafeTextToLine (fromString (showVersion pursVersion)))
+        echo $ "Using the default package set for PureScript compiler version " <>
+          fromString (showVersion pursVersion)
         echo "(Use --source / --set to override this behavior)"
         pure PackageConfig { name    = pkgName
                            , depends = [ preludePackageName ]
diff --git a/src/Language/PureScript/Package/Types/PackageConfig.hs b/src/Language/PureScript/Package/Types/PackageConfig.hs
index 4c6914a..f43d528 100644
--- a/src/Language/PureScript/Package/Types/PackageConfig.hs
+++ b/src/Language/PureScript/Package/Types/PackageConfig.hs
@@ -46,16 +46,14 @@ packageConfigToJSON =
 packageFile :: FilePath
 packageFile = "psc-package.json"
 
-readPackageFile :: IO PackageConfig
+readPackageFile :: MonadIO m => m PackageConfig
 readPackageFile = do
   exists <- testfile packageFile
   unless exists $ die "psc-package.json does not exist. Maybe you need to run psc-package init?"
-  mpkg <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile packageFile
+  mpkg <- liftIO $ Aeson.decodeStrict . encodeUtf8 <$> readTextFile packageFile
   case mpkg of
     Nothing -> die "Unable to parse psc-package.json"
     Just pkg -> return pkg
 
-writePackageFile :: PackageConfig -> IO ()
-writePackageFile =
-  writeTextFile packageFile
-  . packageConfigToJSON
+writePackageFile :: MonadIO m => PackageConfig -> m ()
+writePackageFile = liftIO . writeTextFile packageFile . packageConfigToJSON
diff --git a/src/Language/PureScript/Package/Types/PackageSet.hs b/src/Language/PureScript/Package/Types/PackageSet.hs
index f4eeca9..e7f6943 100644
--- a/src/Language/PureScript/Package/Types/PackageSet.hs
+++ b/src/Language/PureScript/Package/Types/PackageSet.hs
@@ -37,18 +37,18 @@ packageSetToJSON =
   where
     config = AesonEncode.defConfig { AesonEncode.confCompare = compare }
 
-getPackageSet :: PackageConfig -> IO ()
+getPackageSet :: MonadIO m => PackageConfig -> m ()
 getPackageSet PackageConfig{ source, set } = do
   let pkgDir = ".psc-package" </> fromText set </> ".set"
   exists <- testdir pkgDir
   unless exists . void $ cloneShallow source set pkgDir
 
-readPackageSet :: PackageConfig -> IO PackageSet
+readPackageSet :: MonadIO m => PackageConfig -> m PackageSet
 readPackageSet PackageConfig{ set } = do
   let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
   exists <- testfile dbFile
   unless exists $ die $ format (fp%" does not exist") dbFile
-  mdb <- Aeson.decodeStrict . encodeUtf8 <$> readTextFile dbFile
+  mdb <- liftIO $ Aeson.decodeStrict . encodeUtf8 <$> readTextFile dbFile
   case mdb of
     Nothing -> die "Unable to parse packages.json"
     Just db -> return db
@@ -58,7 +58,11 @@ writePackageSet PackageConfig{ set } =
   let dbFile = ".psc-package" </> fromText set </> ".set" </> "packages.json"
   in writeTextFile dbFile . packageSetToJSON
 
-getTransitiveDeps :: PackageSet -> [PackageName] -> IO [(PackageName, PackageInfo)]
+getTransitiveDeps
+  :: MonadIO m
+  => PackageSet
+  -> [PackageName]
+  -> m [(PackageName, PackageInfo)]
 getTransitiveDeps db deps =
     Map.toList . fold <$> traverse (go Set.empty) deps
   where
diff --git a/src/Language/PureScript/Package/Update.hs b/src/Language/PureScript/Package/Update.hs
index 183057d..07b7c1c 100644
--- a/src/Language/PureScript/Package/Update.hs
+++ b/src/Language/PureScript/Package/Update.hs
@@ -10,47 +10,48 @@ module Language.PureScript.Package.Update (
 
 import           Control.Concurrent.Async (forConcurrently_)
 import qualified Data.Text as T
-import           Turtle
+import           Turtle hiding (echo)
 import           Prelude hiding (FilePath)
 
+import Language.PureScript.Package.Echo (MonadEcho(..))
+import Language.PureScript.Package.Git (cloneShallow)
 import Language.PureScript.Package.Types.PackageConfig (PackageConfig(..), readPackageFile, writePackageFile)
 import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
 import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
 import Language.PureScript.Package.Types.PackageSet (readPackageSet, getTransitiveDeps)
-import Language.PureScript.Package.Git (cloneShallow)
 
-update :: IO ()
+update :: (MonadIO m, MonadEcho m) => m ()
 update = do
   pkg <- readPackageFile
   updateImpl pkg
   echo "Update complete"
 
-updateImpl :: PackageConfig -> IO ()
+updateImpl :: (MonadIO m, MonadEcho m) => PackageConfig -> m ()
 updateImpl config@PackageConfig{ depends } = do
   getPackageSet config
   db <- readPackageSet config
   trans <- getTransitiveDeps db depends
-  echo ("Updating " <> unsafeTextToLine (T.pack (show (length trans))) <> " packages...")
-  forConcurrently_ trans . uncurry $ installOrUpdate (set config)
+  echo $ "Updating " <> T.pack (show (length trans)) <> " packages..."
+  liftIO . forConcurrently_ trans . uncurry $ installOrUpdate (set config)
 
   where
-  getPackageSet :: PackageConfig -> IO ()
+  getPackageSet :: MonadIO m => PackageConfig -> m ()
   getPackageSet PackageConfig{ source, set } = do
     let pkgDir = ".psc-package" </> fromText set </> ".set"
     exists <- testdir pkgDir
     unless exists . void $ cloneShallow source set pkgDir
 
-updateAndWritePackageFile :: PackageConfig -> IO ()
+updateAndWritePackageFile :: (MonadIO m, MonadEcho m) => PackageConfig -> m ()
 updateAndWritePackageFile pkg = do
   updateImpl pkg
   writePackageFile pkg
   echo "psc-package.json file was updated"
 
-installOrUpdate :: Text -> PackageName -> PackageInfo -> IO FilePath
+installOrUpdate :: (MonadIO m, MonadEcho m) => Text -> PackageName -> PackageInfo -> m FilePath
 installOrUpdate set pkgName PackageInfo{ repo, version } = do
   let pkgDir = ".psc-package" </> fromText set </> fromText (runPackageName pkgName) </> fromText version
   exists <- testdir pkgDir
   unless exists . void $ do
-    echo $ "Updating " <> unsafeTextToLine (runPackageName pkgName)
+    echo $ "Updating " <> runPackageName pkgName
     cloneShallow repo version pkgDir
   pure pkgDir
diff --git a/src/Language/PureScript/Package/Verify.hs b/src/Language/PureScript/Package/Verify.hs
index 6cf2014..916926a 100644
--- a/src/Language/PureScript/Package/Verify.hs
+++ b/src/Language/PureScript/Package/Verify.hs
@@ -7,22 +7,23 @@ import           Data.Foldable (for_)
 import qualified Data.Map as Map
 import           Data.Maybe (fromMaybe)
 import qualified Data.Text as T
-import           Turtle
+import           Turtle hiding (echo)
 import           Prelude hiding (FilePath)
 
+import Language.PureScript.Package.Echo (MonadEcho(..))
+import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Types.PackageConfig (readPackageFile, set)
 import Language.PureScript.Package.Types.PackageName (runPackageName)
 import Language.PureScript.Package.Types.PackageSet (readPackageSet, getTransitiveDeps)
-import Language.PureScript.Package.Path (pathToTextUnsafe)
 import Language.PureScript.Package.Update (installOrUpdate)
 
-verifyPackageSet :: IO ()
+verifyPackageSet :: (MonadIO m, MonadEcho m) => m ()
 verifyPackageSet = do
   pkg <- readPackageFile
   db <- readPackageSet pkg
 
   echo $
-    "Verifying " <> unsafeTextToLine (T.pack (show (Map.size db))) <> " packages."
+    "Verifying " <> T.pack (show (Map.size db)) <> " packages."
   echo "Warning: this could take some time!"
 
   let installOrUpdate' (name, pkgInfo) = (name, ) <$> installOrUpdate (set pkg) name pkgInfo
@@ -30,7 +31,7 @@ verifyPackageSet = do
 
   for_ (Map.toList db) $ \(name, _) -> do
     let dirFor pkgName = fromMaybe (error ("verifyPackageSet: no directory for " <> show pkgName)) (Map.lookup pkgName paths)
-    echo $ "Verifying package " <> unsafeTextToLine (runPackageName name)
+    echo $ "Verifying package " <> runPackageName name
     dependencies <- map fst <$> getTransitiveDeps db [name]
     let srcGlobs = map (pathToTextUnsafe . (</> ("src" </> "**" </> "*.purs")) . dirFor) dependencies
     procs "purs" ("compile" : srcGlobs) empty

From 74d0267197084cf85271eb8dc17efc84cd6e19de Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Fri, 11 Aug 2017 16:06:17 +0100
Subject: [PATCH 20/22] further conversions to MonadIO/Echo

Also changes some functions parameters from String to Text.
---
 app/Main.hs                                         |  4 ++--
 src/Language/PureScript/Package/Install.hs          | 13 ++++++++-----
 src/Language/PureScript/Package/Paths.hs            |  4 ++--
 .../PureScript/Package/Types/PackageName.hs         |  1 +
 src/Language/PureScript/Package/Uninstall.hs        | 10 +++++++---
 5 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index e6ca05c..6f9df3c 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -203,10 +203,10 @@ main = do
             (Opts.info (pure update)
             (Opts.progDesc "Update dependencies"))
         , Opts.command "uninstall"
-            (Opts.info (uninstall <$> pkg Opts.<**> Opts.helper)
+            (Opts.info (uninstall . T.pack <$> pkg Opts.<**> Opts.helper)
             (Opts.progDesc "Uninstall the named package"))
         , Opts.command "install"
-            (Opts.info (install <$> pkg Opts.<**> Opts.helper)
+            (Opts.info (install . T.pack <$> pkg Opts.<**> Opts.helper)
             (Opts.progDesc "Install the named package"))
         , Opts.command "build"
             (Opts.info (exec ["purs", "compile"]
diff --git a/src/Language/PureScript/Package/Install.hs b/src/Language/PureScript/Package/Install.hs
index c123e2b..56cd4d0 100644
--- a/src/Language/PureScript/Package/Install.hs
+++ b/src/Language/PureScript/Package/Install.hs
@@ -3,16 +3,19 @@
 
 module Language.PureScript.Package.Install (install) where
 
-import           Data.List (nub)
-import           Prelude hiding (FilePath)
+import Control.Monad.IO.Class (MonadIO)
+import Data.List (nub)
+import Data.Text (Text)
+import Prelude hiding (FilePath)
 
+import Language.PureScript.Package.Echo (MonadEcho(..))
 import Language.PureScript.Package.Types.PackageConfig (readPackageFile, depends)
-import Language.PureScript.Package.Types.PackageName (packageNameFromString)
+import Language.PureScript.Package.Types.PackageName (fromText)
 import Language.PureScript.Package.Update (updateAndWritePackageFile)
 
-install :: String -> IO ()
+install :: (MonadIO m, MonadEcho m) => Text -> m ()
 install pkgName' = do
   pkg <- readPackageFile
-  pkgName <- packageNameFromString pkgName'
+  pkgName <- fromText pkgName'
   let pkg' = pkg { depends = nub (pkgName : depends pkg) } -- TODO: ordnub
   updateAndWritePackageFile pkg'
diff --git a/src/Language/PureScript/Package/Paths.hs b/src/Language/PureScript/Package/Paths.hs
index c847f7b..692f3a3 100644
--- a/src/Language/PureScript/Package/Paths.hs
+++ b/src/Language/PureScript/Package/Paths.hs
@@ -12,13 +12,13 @@ import Language.PureScript.Package.Types.PackageInfo (PackageInfo(..))
 import Language.PureScript.Package.Types.PackageName (PackageName, runPackageName)
 import Language.PureScript.Package.Types.PackageSet (PackageSet, readPackageSet, getTransitiveDeps)
 
-getPaths :: IO [FilePath]
+getPaths :: MonadIO m => m [FilePath]
 getPaths = do
   pkg@PackageConfig{..} <- readPackageFile
   db <- readPackageSet pkg
   getSourcePaths pkg db depends
   where
-  getSourcePaths :: PackageConfig -> PackageSet -> [PackageName] -> IO [FilePath]
+  getSourcePaths :: MonadIO m => PackageConfig -> PackageSet -> [PackageName] -> m [FilePath]
   getSourcePaths PackageConfig{..} db pkgNames = do
     trans <- getTransitiveDeps db pkgNames
     let paths = [ ".psc-package"
diff --git a/src/Language/PureScript/Package/Types/PackageName.hs b/src/Language/PureScript/Package/Types/PackageName.hs
index 30de9c0..14b450d 100644
--- a/src/Language/PureScript/Package/Types/PackageName.hs
+++ b/src/Language/PureScript/Package/Types/PackageName.hs
@@ -3,6 +3,7 @@
 module Language.PureScript.Package.Types.PackageName
   ( PackageName
   , mkPackageName
+  , fromText
   , runPackageName
   , packageNameFromString
   , preludePackageName
diff --git a/src/Language/PureScript/Package/Uninstall.hs b/src/Language/PureScript/Package/Uninstall.hs
index 9852c1f..f55af66 100644
--- a/src/Language/PureScript/Package/Uninstall.hs
+++ b/src/Language/PureScript/Package/Uninstall.hs
@@ -1,12 +1,16 @@
 module Language.PureScript.Package.Uninstall (uninstall) where
 
+import Control.Monad.IO.Class (MonadIO)
+import Data.Text (Text)
+
+import Language.PureScript.Package.Echo (MonadEcho(..))
 import Language.PureScript.Package.Types.PackageConfig (readPackageFile, depends)
-import Language.PureScript.Package.Types.PackageName (packageNameFromString)
+import Language.PureScript.Package.Types.PackageName (fromText)
 import Language.PureScript.Package.Update (updateAndWritePackageFile)
 
-uninstall :: String -> IO ()
+uninstall :: (MonadIO m, MonadEcho m) => Text -> m ()
 uninstall pkgName' = do
   pkg <- readPackageFile
-  pkgName <- packageNameFromString pkgName'
+  pkgName <- fromText pkgName'
   let pkg' = pkg { depends = filter (/= pkgName) $ depends pkg }
   updateAndWritePackageFile pkg'

From 188e2b8e5af875ecdf2f78fa5fec8ee8453f800e Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Fri, 11 Aug 2017 16:39:38 +0100
Subject: [PATCH 21/22] add documentation

---
 src/Language/PureScript/Package/Echo.hs       | 7 ++++++-
 src/Language/PureScript/Package/Git.hs        | 2 ++
 src/Language/PureScript/Package/Initialize.hs | 2 ++
 src/Language/PureScript/Package/Install.hs    | 2 ++
 src/Language/PureScript/Package/Path.hs       | 2 ++
 src/Language/PureScript/Package/Paths.hs      | 2 ++
 src/Language/PureScript/Package/Uninstall.hs  | 2 ++
 src/Language/PureScript/Package/Update.hs     | 2 ++
 src/Language/PureScript/Package/Verify.hs     | 4 +++-
 9 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/Language/PureScript/Package/Echo.hs b/src/Language/PureScript/Package/Echo.hs
index e3d31ae..d32718c 100644
--- a/src/Language/PureScript/Package/Echo.hs
+++ b/src/Language/PureScript/Package/Echo.hs
@@ -1,3 +1,7 @@
+-- | Tools for optionally `echo`ing 'Text' to stdout.
+--
+-- Use 'runSilentT' to silence 'echo'ed output in any 'MonadEcho'.
+
 module Language.PureScript.Package.Echo (
   MonadEcho(..)
 , SilentT(..)
@@ -14,7 +18,8 @@ class Applicative m => MonadEcho m where
 instance MonadEcho IO where
   echo = putStrLn
 
-newtype SilentT m a = SilentT { runSilentT :: m a }
+-- | A `MonadEcho` that silences `echo`.
+newtype SilentT m a = SilentT {runSilentT :: m a }
 
 instance Functor m => Functor (SilentT m) where
     fmap f = SilentT . fmap f . runSilentT
diff --git a/src/Language/PureScript/Package/Git.hs b/src/Language/PureScript/Package/Git.hs
index 85fcb4c..1e22acb 100644
--- a/src/Language/PureScript/Package/Git.hs
+++ b/src/Language/PureScript/Package/Git.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 
+-- | Functions for executing git.
+
 module Language.PureScript.Package.Git (
   cloneShallow
 , listRemoteTags
diff --git a/src/Language/PureScript/Package/Initialize.hs b/src/Language/PureScript/Package/Initialize.hs
index eccdbb2..046c6f0 100644
--- a/src/Language/PureScript/Package/Initialize.hs
+++ b/src/Language/PureScript/Package/Initialize.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 
+-- | Initialize a new package, generating its psc-package.json file.
+
 module Language.PureScript.Package.Initialize (initialize) where
 
 import qualified Control.Foldl as Foldl
diff --git a/src/Language/PureScript/Package/Install.hs b/src/Language/PureScript/Package/Install.hs
index 56cd4d0..676306c 100644
--- a/src/Language/PureScript/Package/Install.hs
+++ b/src/Language/PureScript/Package/Install.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE NamedFieldPuns #-}
 
+-- | Install a new package and update the package file.
+
 module Language.PureScript.Package.Install (install) where
 
 import Control.Monad.IO.Class (MonadIO)
diff --git a/src/Language/PureScript/Package/Path.hs b/src/Language/PureScript/Package/Path.hs
index 8f7e4d3..4027f84 100644
--- a/src/Language/PureScript/Package/Path.hs
+++ b/src/Language/PureScript/Package/Path.hs
@@ -1,3 +1,5 @@
+-- | Convert 'FilePath's to 'Text'
+
 module Language.PureScript.Package.Path (pathToTextUnsafe) where
 
 import Turtle (FilePath, Text, toText)
diff --git a/src/Language/PureScript/Package/Paths.hs b/src/Language/PureScript/Package/Paths.hs
index 692f3a3..47f82ce 100644
--- a/src/Language/PureScript/Package/Paths.hs
+++ b/src/Language/PureScript/Package/Paths.hs
@@ -2,6 +2,8 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE RecordWildCards #-}
 
+-- | Get the source paths for a package.
+
 module Language.PureScript.Package.Paths (getPaths) where
 
 import           Turtle
diff --git a/src/Language/PureScript/Package/Uninstall.hs b/src/Language/PureScript/Package/Uninstall.hs
index f55af66..ccfd36f 100644
--- a/src/Language/PureScript/Package/Uninstall.hs
+++ b/src/Language/PureScript/Package/Uninstall.hs
@@ -1,5 +1,7 @@
 module Language.PureScript.Package.Uninstall (uninstall) where
 
+-- | Remove a package from the package file.
+
 import Control.Monad.IO.Class (MonadIO)
 import Data.Text (Text)
 
diff --git a/src/Language/PureScript/Package/Update.hs b/src/Language/PureScript/Package/Update.hs
index 07b7c1c..f9463ce 100644
--- a/src/Language/PureScript/Package/Update.hs
+++ b/src/Language/PureScript/Package/Update.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE NamedFieldPuns #-}
 
+-- | Update (obtain) dependencies/packages.
+
 module Language.PureScript.Package.Update (
   update
 , updateImpl
diff --git a/src/Language/PureScript/Package/Verify.hs b/src/Language/PureScript/Package/Verify.hs
index 916926a..a9ac926 100644
--- a/src/Language/PureScript/Package/Verify.hs
+++ b/src/Language/PureScript/Package/Verify.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TupleSections #-}
 
+-- | Check that a package set can compile.
+
 module Language.PureScript.Package.Verify (verifyPackageSet) where
 
 import           Data.Foldable (for_)
@@ -30,7 +32,7 @@ verifyPackageSet = do
   paths <- Map.fromList <$> traverse installOrUpdate' (Map.toList db)
 
   for_ (Map.toList db) $ \(name, _) -> do
-    let dirFor pkgName = fromMaybe (error ("verifyPackageSet: no directory for " <> show pkgName)) (Map.lookup pkgName paths)
+    let dirFor pkgName = fromMaybe (error $ "verifyPackageSet: no directory for " <> show pkgName) (Map.lookup pkgName paths)
     echo $ "Verifying package " <> runPackageName name
     dependencies <- map fst <$> getTransitiveDeps db [name]
     let srcGlobs = map (pathToTextUnsafe . (</> ("src" </> "**" </> "*.purs")) . dirFor) dependencies

From f2460c67c77a6d236c2408470ed3047e48d6e3ed Mon Sep 17 00:00:00 2001
From: Matthew Leon <ml@matthewleon.com>
Date: Fri, 11 Aug 2017 16:46:28 +0100
Subject: [PATCH 22/22] update package version

---
 psc-package.cabal | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/psc-package.cabal b/psc-package.cabal
index 7b74030..ceac3a5 100644
--- a/psc-package.cabal
+++ b/psc-package.cabal
@@ -1,5 +1,5 @@
 name:                psc-package
-version:             0.2.0
+version:             0.3.0
 synopsis:            An experimental package manager for PureScript
 description:
 homepage:            https://github.com/purescript/psc-package