refactor(jsontools): move to functions, align `is_json` tool to return exit code

Also:

- Fix Python code in accordance with Python 3
- Use CGI module in Ruby to encode/decode strings

plugins/jsontools/jsontools.plugin.zsh

@@ -22,39 +22,83 @@ fi
 # Define json tools for each method
 case "$JSONTOOLS_METHOD" in
   node)
-    alias pp_json='xargs -0 node -e "console.log(JSON.stringify(JSON.parse(process.argv[1]), null, 4));"'
-    alias is_json='xargs -0 node -e "try {json = JSON.parse(process.argv[1]);} catch (e) { console.log(false); json = null; } if(json) { console.log(true); }"'
-    alias urlencode_json='xargs -0 node -e "console.log(encodeURIComponent(process.argv[1]))"'
-    alias urldecode_json='xargs -0 node -e "console.log(decodeURIComponent(process.argv[1]))"'
+    # node doesn't make it easy to deal with stdin, so we pass it as an argument with xargs -0
+    function pp_json() {
+      xargs -0 node -e 'console.log(JSON.stringify(JSON.parse(process.argv[1]), null, 4));'
+    }
+    function is_json() {
+      xargs -0 node -e '
+        try {
+          json = JSON.parse(process.argv[1]);
+          console.log("true");
+          process.exit(0);
+        } catch (e) {
+          console.log("false");
+          process.exit(1);
+        }
+      '
+    }
+    function urlencode_json() {
+      xargs -0 node -e "console.log(encodeURIComponent(process.argv[1]))"
+    }
+    function urldecode_json() {
+      xargs -0 node -e "console.log(decodeURIComponent(process.argv[1]))"
+    }
   ;;
   python)
-    alias pp_json='python -c "import sys; del sys.path[0]; import runpy; runpy._run_module_as_main(\"json.tool\")"'
-    alias is_json='python -c "
+    function pp_json() {
+      python -c 'import sys; del sys.path[0]; import runpy; runpy._run_module_as_main("json.tool")'
+    }
+    function is_json() {
+      python -c '
 import sys; del sys.path[0];
-import json;
-try: 
-    json.loads(sys.stdin.read())
-except ValueError, e: 
-    print False
-else:
-    print True
-sys.exit(0)"'
-    alias urlencode_json='python -c "
+import json
+try:
+  json.loads(sys.stdin.read())
+  print("true"); sys.exit(0)
+except ValueError:
+  print("false"); sys.exit(1)
+      '
+    }
+    function urlencode_json() {
+      python -c '
 import sys; del sys.path[0];
-import urllib, json;
-print urllib.quote_plus(sys.stdin.read())
-sys.exit(0)"'
-    alias urldecode_json='python -c "
+from urllib.parse import quote_plus
+print(quote_plus(sys.stdin.read()))
+      '
+    }
+    function urldecode_json() {
+      python -c '
 import sys; del sys.path[0];
-import urllib, json;
-print urllib.unquote_plus(sys.stdin.read())
-sys.exit(0)"'
+from urllib.parse import unquote_plus
+print(unquote_plus(sys.stdin.read()))
+      '
+    }
   ;;
   ruby)
-    alias pp_json='ruby -e "require \"json\"; require \"yaml\"; puts JSON.parse(STDIN.read).to_yaml"'
-    alias is_json='ruby -e "require \"json\"; begin; JSON.parse(STDIN.read); puts true; rescue Exception => e; puts false; end"'
-    alias urlencode_json='ruby -e "require \"uri\"; puts URI.escape(STDIN.read)"'
-    alias urldecode_json='ruby -e "require \"uri\"; puts URI.unescape(STDIN.read)"'
+    function pp_json() {
+      ruby -e '
+        require "json"
+        require "yaml"
+        puts JSON.parse(STDIN.read).to_yaml
+      '
+    }
+    function is_json() {
+      ruby -e '
+        require "json"
+        begin
+          puts !!JSON.parse(STDIN.read); exit(0)
+        rescue JSON::ParserError
+          puts false; exit(1)
+        end
+      '
+    }
+    function urlencode_json() {
+      ruby -e 'require "cgi"; puts CGI.escape(STDIN.read)'
+    }
+    function urldecode_json() {
+      ruby -e 'require "cgi"; puts CGI.unescape(STDIN.read)'
+    }
   ;;
 esac