Update editor reading/writing mechanism

.travis.yml

@@ -8,7 +8,7 @@ before_install:
     - go get -t -v ./...
 
 script: 
-    - go test -race -coverprofile=coverage.txt -covermode=atomic `go list ./...`
+    - go test -race -coverprofile=coverage.txt -covermode=atomic `go list ./... | grep -v testhelper`
 
 after_success:
     - bash <(curl -s https://codecov.io/bash)

editor/content.go

@@ -7,7 +7,9 @@ import (
 	"strings"
 )
 
-// Content holds all I/O related logic of the editor
+// Content represents the lines read from a io.Reader
+// `c` holds the actual lines and
+// `reader` contains the io.Reader representation of the lines
 type Content struct {
 	c      []string
 	reader io.Reader
@@ -18,30 +20,40 @@ func (c Content) Read(b []byte) (int, error) {
 }
 
 func (c Content) String() string {
-	return strings.Join(c.c, "\n")
+	return strings.Join(c.c, "")
 }
 
 // contentFromReader creates a new `Content` object
-// by scanning an io.Reader using a bufio.SplitFunc
-func contentFromReader(content io.Reader, split bufio.SplitFunc) (Content, error) {
-	c := Content{}
-	scanner := bufio.NewScanner(content)
-	scanner.Split(split)
-
-	for scanner.Scan() {
-		c.c = append(c.c, scanner.Text())
+// filled with the lines from the provided Reader
+// It returns an error if anything other than io.EOF is raised
+func contentFromReader(content io.Reader) (c Content, err error) {
+	reader := bufio.NewReader(content)
+
+	for {
+		line, err := reader.ReadString('\n')
+		c.c = append(c.c, line)
+
+		if err != nil {
+			break
+		}
+	}
+
+	if err != nil && err != io.EOF {
+		return
 	}
-	c.reader = strings.NewReader(c.String())
 
-	return c, scanner.Err()
+	c.reader = strings.NewReader(c.String())
+	return
 }
 
-func contentFromFile(filename string, split bufio.SplitFunc) (Content, error) {
+// contentFromFile reads the content from the file
+// It returns an error if the file does not exist
+func contentFromFile(filename string) (Content, error) {
 	file, err := os.Open(filename)
 	if err != nil {
 		return Content{}, err
 	}
 	defer file.Close()
 
-	return contentFromReader(file, split)
+	return contentFromReader(file)
 }

editor/content_test.go

@@ -1,7 +1,6 @@
 package editor
 
 import (
-	"bufio"
 	"io/ioutil"
 	"strings"
 	"testing"
@@ -10,7 +9,7 @@ import (
 )
 
 func TestUseContentAsReader(t *testing.T) {
-	c, err := contentFromReader(strings.NewReader("foo\nbar"), bufio.ScanLines)
+	c, err := contentFromReader(strings.NewReader("foo\nbar"))
 	testhelper.Ok(t, err)
 
 	byteCnt, err := ioutil.ReadAll(c)
@@ -24,8 +23,8 @@ func TestCreateContentFromFile(t *testing.T) {
 	_, err = f.Write([]byte("foo\nbar"))
 	testhelper.Ok(t, err)
 
-	c, err := contentFromFile(f.Name(), bufio.ScanLines)
+	c, err := contentFromFile(f.Name())
 
-	testhelper.Equals(t, c.c[0], "foo")
-	testhelper.Equals(t, c.c[1], "bar")
+	testhelper.Equals(t, "foo\n", c.c[0])
+	testhelper.Equals(t, "bar", c.c[1])
 }

editor/editor.go

@@ -4,7 +4,6 @@ package editor
 // https://github.com/kioopi/extedit
 
 import (
-	"bufio"
 	"io"
 	"io/ioutil"
 	"os"
@@ -16,19 +15,16 @@ import (
 
 const defaultEditor = "vim"
 
-type Session struct {
-	input     Content
-	SplitFunc bufio.SplitFunc
-}
+var execCommand = exec.Command
 
-// Open starts a text-editor with the contents of content.
-// It returns edited content after user closes the editor
+// Open starts a text-editor with lines from `Content`
+// It returns the manually edited lines from the text-editor when the user closes the editor
 func Open(c *conflict.Conflict) (output []string, err error) {
-	s := &Session{SplitFunc: bufio.ScanLines}
 	lines := c.File.Lines[c.Start : c.End+1]
 
 	content := strings.NewReader(strings.Join(lines, ""))
-	input, err := contentFromReader(content, s.SplitFunc)
+	input, err := contentFromReader(content)
+
 	if err != nil {
 		return
 	}
@@ -44,20 +40,17 @@ func Open(c *conflict.Conflict) (output []string, err error) {
 		return
 	}
 
-	newContent, err := contentFromFile(fileName, s.SplitFunc)
+	newContent, err := contentFromFile(fileName)
 	if err != nil {
 		return
 	}
 
 	output = newContent.c
-	for i := range output {
-		output[i] = output[i] + "\n"
-	}
 	return
 }
 
-// writeTmpFile writes content to a temporary file and returns
-// the path to the file
+// writeTmpFile writes content to a temporary file and returns the path to the file
+// It returns an error if the temporary file cannot be created
 func writeTmpFile(content io.Reader) (string, error) {
 	f, err := ioutil.TempFile("", "")
 	if err != nil {
@@ -69,14 +62,14 @@ func writeTmpFile(content io.Reader) (string, error) {
 	return f.Name(), nil
 }
 
-// editorCmd creates a os/exec.Cmd to open
-// filename in an editor ready to be run()
+// editorCmd returns a os/exec.Cmd to open the provided file
 func editorCmd(filename string) *exec.Cmd {
 	editorPath := os.Getenv("EDITOR")
 	if editorPath == "" {
 		editorPath = defaultEditor
 	}
-	editor := exec.Command(editorPath, filename)
+
+	editor := execCommand(editorPath, filename)
 
 	editor.Stdin = os.Stdin
 	editor.Stdout = os.Stdout

editor/editor_test.go

@@ -1,9 +1,12 @@
 package editor
 
 import (
+	"os"
+	"os/exec"
 	"strings"
 	"testing"
 
+	"github.com/mkchoi212/fac/conflict"
 	"github.com/mkchoi212/fac/testhelper"
 )
 
@@ -19,3 +22,36 @@ func TestWriteTmpFile(t *testing.T) {
 	testhelper.Ok(t, err)
 	testhelper.Assert(t, name != "", "tmp file name should not be empty")
 }
+
+func TestOpen(t *testing.T) {
+	execCommand = mockExecCommand
+	defer func() { execCommand = exec.Command }()
+
+	f := conflict.File{AbsolutePath: "testdata/lorem_ipsum"}
+	err := f.Read()
+	testhelper.Ok(t, err)
+
+	c := conflict.Conflict{File: &f, Start: 0, End: 5}
+	output, err := Open(&c)
+
+	testhelper.Ok(t, err)
+	testhelper.Equals(t, f.Lines, output)
+}
+
+func TestHelperProcess(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+
+	os.Exit(0)
+}
+
+// Allows us to mock exec.Command, thanks to
+// https://npf.io/2015/06/testing-exec-command/
+func mockExecCommand(command string, args ...string) *exec.Cmd {
+	cs := []string{"-test.run=TestHelperProcess", "--", command}
+	cs = append(cs, args...)
+	cmd := exec.Command(os.Args[0], cs...)
+	cmd.Env = append(cmd.Env, "GO_WANT_HELPER_PROCESS=1")
+	return cmd
+}