Generate the integrity hash from compiled asset content

Author: rafaelfranca

lib/propshaft/asset.rb

@@ -18,6 +18,10 @@ def initialize(path, logical_path:, load_path:)
     @path, @logical_path, @load_path = path, Pathname.new(logical_path), load_path
   end
 
+  def compiled_content
+    @compiled_content ||= load_path.compilers.compile(self)
+  end
+
   def content(encoding: "ASCII-8BIT")
     File.read(path, encoding: encoding, mode: "rb")
   end
@@ -49,7 +53,7 @@ def integrity(hash_algorithm:)
         raise(StandardError.new("Subresource Integrity hash algorithm must be one of SHA2 family (sha256, sha384, sha512)"))
       end
 
-    [hash_algorithm, Digest::SHA2.new(bitlen).base64digest(content)].join("-")
+    [hash_algorithm, Digest::SHA2.new(bitlen).base64digest(compiled_content)].join("-")
   end
 
   def digested_path

lib/propshaft/processor.rb

@@ -54,10 +54,10 @@ def output_asset(asset)
     def compile_asset(asset)
       File.open(output_path.join(asset.digested_path), "w+") do |file|
         begin
-          file.write compilers.compile(asset)
+          file.write asset.compiled_content
         rescue Encoding::UndefinedConversionError
           # FIXME: Not sure if there's a better way here?
-          file.write compilers.compile(asset).force_encoding("UTF-8")
+          file.write asset.compiled_content.force_encoding("UTF-8")
         end
       end if compilers.compilable?(asset)
     end

lib/propshaft/resolver/dynamic.rb

@@ -16,7 +16,7 @@ def integrity(logical_path)
       hash_algorithm = load_path.integrity_hash_algorithm
 
       if hash_algorithm && (asset = find_asset(logical_path))
-        asset.integrity(hash_algorithm:)
+        asset.integrity(hash_algorithm: hash_algorithm)
       end
     end
 

lib/propshaft/server.rb

@@ -11,7 +11,7 @@ def call(env)
     path, digest = extract_path_and_digest(env)
 
     if (asset = @assembly.load_path.find(path)) && asset.fresh?(digest)
-      compiled_content = @assembly.compilers.compile(asset)
+      compiled_content = asset.compiled_content
 
       [
         200,

test/propshaft/asset_test.rb

@@ -71,6 +71,21 @@ class Propshaft::AssetTest < ActiveSupport::TestCase
     assert_equal find_asset("one.txt"), find_asset("one.txt")
   end
 
+  test "compiled content for non-compilable asset" do
+    asset = find_asset("one.txt")
+    assert_equal "One from first path", asset.compiled_content
+    assert_equal asset.content, asset.compiled_content
+  end
+
+  test "compiled content for css asset with url transformation" do
+    asset = find_asset("another.css")
+    compiled = asset.compiled_content
+
+    assert_match(/url\("\/archive-[a-f0-9]+\.svg"\)/, compiled)
+    assert_not_equal asset.content, asset.compiled_content
+  end
+
+
   test "costly methods are memoized" do
     asset = find_asset("one.txt")
     assert_equal asset.digest.object_id, asset.digest.object_id

test/propshaft/manifest_test.rb

@@ -12,7 +12,7 @@ class Propshaft::ManifestTest < ActiveSupport::TestCase
 
     manifest_entry = parsed_manifest["another.css"]
     assert_equal "another-c464b1ee.css", manifest_entry["digested_path"]
-    assert_equal "sha384-RZLbo+FZ8rnE9ct6dNqDcgIYo7DBk/GaB4nCMnNsj6HWp0ePV8q8qky9Qemdpuwl", manifest_entry["integrity"]
+    assert_equal "sha384-jUiHGq2aPNACr4g68crM1I28TitXJKYhEgokcX6W5VYGwufEKQxfLpe4GakM84ex", manifest_entry["integrity"]
   end
 
   test "serializes to the extensible manifest format without integrity hash algorithm" do

test/propshaft/resolver/dynamic_test.rb

@@ -30,6 +30,12 @@ class Propshaft::Resolver::DynamicTest < ActiveSupport::TestCase
     assert_equal "sha384-LdS8l2QTAF8bD8WPb8QSQv0skTWHhmcnS2XU5LBkVQneGzqIqnDRskQtJvi7ADMe", resolver.integrity("one.txt")
   end
 
+  test "integrity for asset return the value for the compiled content instead of the source" do
+    compilers = [["text/css", Propshaft::Compiler::CssAssetUrls ]]
+    resolver = create_resolver(integrity_hash_algorithm: "sha384", compilers: compilers)
+    assert_equal "sha384-jUiHGq2aPNACr4g68crM1I28TitXJKYhEgokcX6W5VYGwufEKQxfLpe4GakM84ex", resolver.integrity("another.css")
+  end
+
   test "integrity for asset returns nil for no configured hash format" do
     assert_nil @resolver.integrity("one.txt")
   end
@@ -40,12 +46,15 @@ class Propshaft::Resolver::DynamicTest < ActiveSupport::TestCase
   end
 
   private
-    def create_resolver(integrity_hash_algorithm: nil)
-      load_path = Propshaft::LoadPath.new(
-        Pathname.new("#{__dir__}/../../fixtures/assets/first_path"),
-        compilers: Propshaft::Compilers.new(nil),
-        integrity_hash_algorithm: integrity_hash_algorithm
-      )
-      Propshaft::Resolver::Dynamic.new(load_path: load_path, prefix: "/assets")
+    def create_resolver(integrity_hash_algorithm: nil, compilers: [])
+      assembly = Propshaft::Assembly.new(ActiveSupport::OrderedOptions.new.tap { |config|
+        config.paths = [
+          Pathname.new("#{__dir__}/../../fixtures/assets/first_path"),
+        ]
+        config.compilers = compilers
+        config.integrity_hash_algorithm = integrity_hash_algorithm
+      })
+
+      Propshaft::Resolver::Dynamic.new(load_path: assembly.load_path, prefix: "/assets")
     end
 end