Add json checks (useful for metadata.json)

This patch provides syntax checks for metadata.json, a file that helps
define characteristics of a puppet modue (usually pertaining to puppet
forge). The error provided by this check tends to be vague or misleading
(such is the nature when referencing improperly formatted structured
data).

Fixes: #11

Author: drwahl

commit_hooks/json_syntax_check.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+# This script expects $1 to be passed and for $1 to be the filesystem location
+# to a json file for which it will run syntax checks against.
+
+syntax_errors=0
+error_msg=$(mktemp /tmp/error_msg_json-syntax.XXXXX)
+
+if [ $2 ]; then
+    module_path=$(echo $1 | sed -e 's|'$2'||')
+else
+    module_path=$1
+fi
+
+# Get list of new/modified manifest and template files to check (in git index)
+# Check json file syntax
+echo -e "\x1B[0;36mChecking json syntax for $module_path...\x1B[0m"
+ruby -e "require 'json'; JSON.parse(File.read($1))" 2> $error_msg > /dev/null
+if [ $? -ne 0 ]; then
+    echo -en "\x1B[0;31m"
+    cat $error_msg
+    syntax_errors=`expr $syntax_errors + 1`
+    echo -e "Error: json syntax error in $module_path (see above)\x1B[0m"
+fi
+rm -f $error_msg
+
+if [ "$syntax_errors" -ne 0 ]; then
+    echo -e "\x1B[0;31mError: $syntax_errors syntax error(s) found in json file.  Commit will be aborted.\x1B[0m"
+    exit 1
+fi
+
+exit 0

pre-commit

@@ -67,8 +67,17 @@ for changedfile in `git diff --cached --name-only --diff-filter=ACM`; do
                 failures=`expr $failures + 1`
             fi
         fi
+
+        #check json (i.e. metadata.json) syntax
+        if [ $(echo $changedfile | grep -q '\.*.json$'; echo $?) -eq 0 ]; then 
+            ${subhook_root}/json_syntax_check.sh $changedfile
+            RC=$?
+            if [ "$RC" -ne 0 ]; then
+                failures=`expr $failures + 1`
+            fi
+        fi
     else
-        echo "ruby not installed. Skipping erb/yaml checks..."
+        echo "ruby not installed. Skipping erb/yaml/json checks..."
     fi
 
     #puppet manifest styleguide compliance