updated docs, fixed tools.cli error printing

Author: reflechant

README.md

@@ -1,10 +1,16 @@
 # json-diff
 
-A console program to produce colorized **structural diff** of two JSON files
+A console program to produce **structural diff** of two JSON files
 
 ## Usage
 
-    $ java -jar json-diff.jar file1.json file2.json
+    $ java -jar json-diff.jar [-m {visual|patch}] file1.json file2.json
+
+`-m` or `--mode` lets you choose output format.
+
+`visual` prints **all** JSON, marking difference in-place. It's made with [deep-diff2](https://github.com/lambdaisland/deep-diff2).
+
+`patch` prints the minimal necessary changes needed to make file2 from file1. It's made with [editscript](https://github.com/juji-io/editscript).
 
 ## License
 

src/json_diff/core.clj

@@ -1,5 +1,6 @@
 (ns json-diff.core
-  (:require [clojure.java.io :as io]
+  (:require [clojure.string :as str]
+            [clojure.java.io :as io]
             [clojure.data.json :as json]
             [clojure.core.async :refer [>! <!! go chan]]
             [clojure.tools.cli :refer [parse-opts]]
@@ -51,7 +52,7 @@
          errors :errors
          {:keys [mode]} :options} (parse-opts args cli-options)]
     (cond
-      errors (print-error-exit (str errors) 1)
+      errors (print-error-exit (str/join "\n" errors) 1)
       (not= 2 (count files)) (print-error-exit "you need to pass two JSON files!" 1)
       (= :visual mode) (apply process diff files)
       (= :patch mode) (apply process patch files))))