func diffValues(expected, actual interface{}) string {
differ := gojsondiff.New()
var diff gojsondiff.Diff
if ve, ok := expected.(map[string]interface{}); ok {
if va, ok := actual.(map[string]interface{}); ok {
diff = differ.CompareObjects(ve, va)
} else {
return " (unavailable)"
}
} else if ve, ok := expected.([]interface{}); ok {
if va, ok := actual.([]interface{}); ok {
diff = differ.CompareArrays(ve, va)
} else {
return " (unavailable)"
}
} else {
return " (unavailable)"
}
formatter := formatter.NewAsciiFormatter(expected)
formatter.ShowArrayIndex = true
str, err := formatter.Format(diff)
if err != nil {
return " (unavailable)"
}
return "--- expected\n+++ actual\n" + str
}
func main() {
app := cli.NewApp()
app.Name = "jd"
app.Usage = "JSON Diff"
app.Version = "0.0.2"
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "format, f",
Value: "ascii",
Usage: "Diff Outpu Format (ascii, delta)",
EnvVar: "DIFF_FORMAT",
},
}
app.Action = func(c *cli.Context) {
if len(c.Args()) < 2 {
fmt.Println("Not enough arguments.\n")
fmt.Printf("Usage: %s json_file another_json_file\n", app.Name)
os.Exit(1)
}
aFilePath := c.Args()[0]
bFilePath := c.Args()[1]
// Prepare your JSON string as `[]byte`, not `string`
aString, err := ioutil.ReadFile(aFilePath)
if err != nil {
fmt.Printf("Failed to open file '%s': %s\n", aFilePath, err.Error())
os.Exit(2)
}
// Another JSON string
bString, err := ioutil.ReadFile(bFilePath)
if err != nil {
fmt.Printf("Failed to open file '%s': %s\n", bFilePath, err.Error())
os.Exit(2)
}
// Then, compare them
differ := diff.New()
d, err := differ.Compare(aString, bString)
if err != nil {
fmt.Printf("Failed to unmarshal file: %s\n", err.Error())
os.Exit(3)
}
// Output the result
format := c.String("format")
var diffString string
if format == "ascii" {
var aJson map[string]interface{}
json.Unmarshal(aString, &aJson)
formatter := formatter.NewAsciiFormatter(aJson)
formatter.ShowArrayIndex = true
diffString, err = formatter.Format(d)
if err != nil {
// No error can occur
}
fmt.Print(diffString)
} else if format == "delta" {
formatter := formatter.NewDeltaFormatter()
diffString, err = formatter.Format(d)
if err != nil {
// No error can occur
}
} else {
fmt.Printf("Unknown Foramt %s\n", format)
os.Exit(4)
}
fmt.Println(diffString)
}
app.Run(os.Args)
}