Refactor to github.Editor to make it testable

commands/issue.go

@@ -92,5 +92,10 @@ func writeIssueTitleAndBody(project *github.Project) (string, string, error) {
 `
 	message = fmt.Sprintf(message, project.Name)
 
-	return github.GetTitleAndBodyFromEditor("ISSUE", message)
+	editor, err := github.NewEditor("ISSUE", message)
+	if err != nil {
+		return "", "", err
+	}
+
+	return editor.EditTitleAndBody()
 }

commands/pull_request.go

@@ -183,9 +183,16 @@ func pullRequest(cmd *Command, args *Args) {
 
 func writePullRequestTitleAndBody(base, head, fullBase, fullHead string, commits []string) (title, body string, err error) {
 	message, err := pullRequestChangesMessage(base, head, fullBase, fullHead, commits)
-	utils.Check(err)
+	if err != nil {
+		return
+	}
 
-	return github.GetTitleAndBodyFromEditor("PULLREQ", message)
+	editor, err := github.NewEditor("PULLREQ", message)
+	if err != nil {
+		return
+	}
+
+	return editor.EditTitleAndBody()
 }
 
 func pullRequestChangesMessage(base, head, fullBase, fullHead string, commits []string) (string, error) {

commands/release.go

@@ -121,7 +121,12 @@ func writeReleaseTitleAndBody(project *github.Project, tag, currentBranch string
 `
 	message = fmt.Sprintf(message, tag, project.Name, currentBranch)
 
-	return github.GetTitleAndBodyFromEditor("RELEASE", message)
+	editor, err := github.NewEditor("RELEASE", message)
+	if err != nil {
+		return "", "", err
+	}
+
+	return editor.EditTitleAndBody()
 }
 
 func getAssetsDirectory(assetsDir, tag string) (string, error) {

github/editor.go

@@ -2,6 +2,7 @@ package github
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"github.com/jingweno/gh/cmd"
 	"github.com/jingweno/gh/git"
@@ -35,47 +36,74 @@ func GetTitleAndBodyFromFlags(messageFlag, fileFlag string) (title, body string,
 	return
 }
 
-func GetTitleAndBodyFromEditor(about, message string) (title, body string, err error) {
-	messageFile, err := getMessageFile(about)
-	if err != nil {
-		return
-	}
-	defer os.Remove(messageFile)
-
-	if message != "" {
-		err = ioutil.WriteFile(messageFile, []byte(message), 0644)
-		if err != nil {
-			return
-		}
-	}
-
-	editor, err := git.Editor()
+func NewEditor(topic, message string) (editor *Editor, err error) {
+	messageFile, err := getMessageFile(topic)
 	if err != nil {
 		return
 	}
 
-	err = editTitleAndBody(editor, messageFile)
+	program, err := git.Editor()
 	if err != nil {
-		err = fmt.Errorf("error using text editor for title/body message")
 		return
 	}
 
-	title, body, err = readTitleAndBody(messageFile)
-	if err != nil {
-		return
+	editor = &Editor{
+		Program: program,
+		File:    messageFile,
+		Message: message,
+		doEdit:  doTextEditorEdit,
 	}
 
 	return
 }
 
-func editTitleAndBody(editor, messageFile string) error {
-	editCmd := cmd.New(editor)
+type Editor struct {
+	Program string
+	File    string
+	Message string
+	doEdit  func(program, file string) error
+}
+
+func (e *Editor) Edit() (content []byte, err error) {
+	if e.Message != "" {
+		err = ioutil.WriteFile(e.File, []byte(e.Message), 0644)
+		if err != nil {
+			return
+		}
+	}
+	defer os.Remove(e.File)
+
+	err = e.doEdit(e.Program, e.File)
+	if err != nil {
+		err = fmt.Errorf("error using text editor for editing message")
+		return
+	}
+
+	content, err = ioutil.ReadFile(e.File)
+
+	return
+}
+
+func (e *Editor) EditTitleAndBody() (title, body string, err error) {
+	content, err := e.Edit()
+	if err != nil {
+		return
+	}
+
+	reader := bufio.NewReader(bytes.NewReader(content))
+	title, body, err = readTitleAndBodyFrom(reader)
+
+	return
+}
+
+func doTextEditorEdit(program, file string) error {
+	editCmd := cmd.New(program)
 	r := regexp.MustCompile("[mg]?vi[m]$")
-	if r.MatchString(editor) {
+	if r.MatchString(program) {
 		editCmd.WithArg("-c")
 		editCmd.WithArg("set ft=gitcommit tw=0 wrap lbr")
 	}
-	editCmd.WithArg(messageFile)
+	editCmd.WithArg(file)
 
 	return editCmd.Exec()
 }

github/editor_test.go

@@ -3,10 +3,64 @@ package github
 import (
 	"bufio"
 	"github.com/bmizerany/assert"
+	"io/ioutil"
+	"os"
 	"strings"
 	"testing"
 )
 
+func TestEditor_Edit(t *testing.T) {
+	tempFile, _ := ioutil.TempFile("", "editor-test")
+	editor := Editor{
+		Program: "memory",
+		File:    tempFile.Name(),
+		doEdit: func(program string, file string) error {
+			assert.Equal(t, "memory", program)
+			assert.Equal(t, tempFile.Name(), file)
+
+			return ioutil.WriteFile(file, []byte("hello"), 0644)
+		},
+	}
+
+	content, err := editor.Edit()
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "hello", string(content))
+
+	// file is removed after edit
+	_, err = os.Stat(tempFile.Name())
+	assert.T(t, os.IsNotExist(err))
+}
+
+func TestEditor_EditTitleAndBody(t *testing.T) {
+	tempFile, _ := ioutil.TempFile("", "editor-test")
+	editor := Editor{
+		Program: "memory",
+		File:    tempFile.Name(),
+		doEdit: func(program string, file string) error {
+			assert.Equal(t, "memory", program)
+			assert.Equal(t, tempFile.Name(), file)
+
+			message := `A title
+A title continues
+
+A body
+A body continues
+# comment
+`
+			return ioutil.WriteFile(file, []byte(message), 0644)
+		},
+	}
+
+	title, body, err := editor.EditTitleAndBody()
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "A title A title continues", title)
+	assert.Equal(t, "A body\nA body continues", body)
+
+	// file is removed after edit
+	_, err = os.Stat(tempFile.Name())
+	assert.T(t, os.IsNotExist(err))
+}
+
 func TestReadTitleAndBody(t *testing.T) {
 	message := `A title
 A title continues