Added json output functionality

README.md

@@ -160,3 +160,6 @@ b:
     - name: Howdy Partner
 ```
 
+## Convert to json
+To convert output to json, use the --tojson (or -j) flag. This can be used with any command.
+

json_converter.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"encoding/json"
+)
+
+func jsonToString(context interface{}) string {
+	out, err := json.Marshal(toJSON(context))
+	if err != nil {
+		die("error printing yaml as json: ", err)
+	}
+	return string(out)
+}
+
+func toJSON(context interface{}) interface{} {
+	switch context.(type) {
+	case []interface{}:
+		oldArray := context.([]interface{})
+		newArray := make([]interface{}, len(oldArray))
+		for index, value := range oldArray {
+			newArray[index] = toJSON(value)
+		}
+		return newArray
+	case map[interface{}]interface{}:
+		oldMap := context.(map[interface{}]interface{})
+		newMap := make(map[string]interface{})
+		for key, value := range oldMap {
+			newMap[key.(string)] = toJSON(value)
+		}
+		return newMap
+	default:
+		return context
+	}
+}

json_converter_test.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestJsonToString(t *testing.T) {
+	var data = parseData(`
+---
+b:
+  c: 2
+`)
+	assertResult(t, "{\"b\":{\"c\":2}}", jsonToString(data))
+}
+
+func TestJsonToString_withArray(t *testing.T) {
+	var data = parseData(`
+---
+b:
+  - item: one
+  - item: two
+`)
+	assertResult(t, "{\"b\":[{\"item\":\"one\"},{\"item\":\"two\"}]}", jsonToString(data))
+}

yaml.go

@@ -13,6 +13,7 @@ import (
 var trimOutput = true
 var writeInplace = false
 var writeScript = ""
+var outputToJSON = false
 
 func main() {
 	var cmdRead = &cobra.Command{
@@ -59,12 +60,13 @@ a.b.e:
 
 	var rootCmd = &cobra.Command{Use: "yaml"}
 	rootCmd.PersistentFlags().BoolVarP(&trimOutput, "trim", "t", true, "trim yaml output")
+	rootCmd.PersistentFlags().BoolVarP(&outputToJSON, "tojson", "j", false, "output as json")
 	rootCmd.AddCommand(cmdRead, cmdWrite)
 	rootCmd.Execute()
 }
 
 func readProperty(cmd *cobra.Command, args []string) {
-	printYaml(read(args))
+	print(read(args))
 }
 
 func read(args []string) interface{} {
@@ -86,7 +88,7 @@ func writeProperty(cmd *cobra.Command, args []string) {
 	if writeInplace {
 		ioutil.WriteFile(args[0], []byte(yamlToString(updatedData)), 0644)
 	} else {
-		printYaml(updatedData)
+		print(updatedData)
 	}
 }
 
@@ -128,8 +130,14 @@ func parseValue(argument string) interface{} {
 	return argument[1 : len(argument)-1]
 }
 
-func printYaml(context interface{}) {
-	fmt.Println(yamlToString(context))
+func print(context interface{}) {
+	var out string
+	if outputToJSON {
+		out = jsonToString(context)
+	} else {
+		out = yamlToString(context)
+	}
+	fmt.Println(out)
 }
 
 func yamlToString(context interface{}) string {