Add file diff into go test

Author: Wuvist

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/labstack/gommon v0.2.8 // indirect
 	github.com/mattn/go-colorable v0.0.9 // indirect
 	github.com/mattn/go-isatty v0.0.4 // indirect
+	github.com/sergi/go-diff v1.0.0
 	github.com/spf13/cobra v0.0.3
 	github.com/spf13/pflag v1.0.2
 	github.com/stretchr/testify v1.3.0 // indirect

go.sum

@@ -14,6 +14,8 @@ github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
+github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/cobra v0.0.3 h1:ZlrZ4XsMRm04Fr5pSFxBgfND2EBVa1nLpiy1stUsX/8=
 github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
 github.com/spf13/pflag v1.0.2 h1:Fy0orTDgHdbnzHcsOgfCN4LtHf0ec3wwtiwJqwvf3Gc=

main_test.go

@@ -2,12 +2,16 @@ package main
 
 import (
 	"bytes"
+	"fmt"
+	"io/ioutil"
 	"os"
 	"path"
+	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
 
+	"github.com/sergi/go-diff/diffmatchpatch"
 	"github.com/yoozoo/protoapi/cmd"
 )
 
@@ -89,4 +93,41 @@ func TestCmd(t *testing.T) {
 			test(t, cmd)
 		}
 	}
+
+	files, err := filePathWalkDir("test/expected")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, expectedFileName := range files {
+		resultFileName := strings.Replace(expectedFileName, "expected", "result", 1)
+
+		expectedFile, err := ioutil.ReadFile(expectedFileName)
+		if err != nil {
+			t.Error("expectedFile read err: ", expectedFileName, err)
+		}
+
+		resultFile, err := ioutil.ReadFile(resultFileName)
+		if err != nil {
+			t.Error("resultFile read err: ", resultFileName, err)
+		}
+
+		if string(expectedFile) != string(resultFile) {
+			dmp := diffmatchpatch.New()
+			diffs := dmp.DiffMain(string(expectedFile), string(resultFile), false)
+			t.Error("file different: ", expectedFileName, resultFileName)
+			fmt.Println(dmp.DiffPrettyText(diffs))
+		}
+	}
+}
+
+func filePathWalkDir(root string) ([]string, error) {
+	var files []string
+	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
+		if !info.IsDir() {
+			files = append(files, path)
+		}
+		return nil
+	})
+	return files, err
 }