terraform/helper/structure/normalize_json.go

package structure

import "encoding/json"

// Takes a value containing JSON string and passes it through
// the JSON parser to normalize it, returns either a parsing
// error or normalized JSON string.
func NormalizeJsonString(jsonString interface{}) (string, error) {
	var j interface{}

	if jsonString == nil || jsonString.(string) == "" {
		return "", nil
	}

	s := jsonString.(string)

	err := json.Unmarshal([]byte(s), &j)
	if err != nil {
		return s, err
	}

	bytes, _ := json.Marshal(j)
	return string(bytes[:]), nil
}