no prior file exists ok

cmd/pttodo-cli/cli.go

@@ -125,11 +125,11 @@ func add(dry bool, filepaths []string, todo pttodo.Todo) error {
 	target := filepaths[0]
 	var original pttodo.Root
 
-	b, err := ioutil.ReadFile(target)
-	if err != nil && !os.IsNotExist(err) {
+	r, err := filePathReader(target)
+	if err != nil {
 		return err
 	}
-	if err := yaml.Unmarshal(b, &original); err != nil {
+	if err := yaml.NewDecoder(r).Decode(&original); err != nil {
 		return err
 	}
 
@@ -157,9 +157,9 @@ func edit(dry bool, filepaths []string) error {
 	originals := map[string]pttodo.Root{}
 	for _, target := range filepaths {
 		var original pttodo.Root
-		if b, err := ioutil.ReadFile(target); err != nil && !os.IsNotExist(err) {
+		if r, err := filePathReader(target); err != nil {
 			return err
-		} else if err := yaml.Unmarshal(b, &original); err != nil {
+		} else if err := yaml.NewDecoder(r).Decode(&original); err != nil {
 			return err
 		} else if c, err := yaml.Marshal(original.Todo); err != nil {
 			return err
@@ -175,9 +175,9 @@ func edit(dry bool, filepaths []string) error {
 		for {
 			err := func() error {
 				var todos []pttodo.Todo
-				if b, err := ioutil.ReadFile(path.Join(tempDir, path.Base(target))); err != nil {
+				if r, err := filePathReader(path.Join(tempDir, path.Base(target))); err != nil {
 					return err
-				} else if err := yaml.Unmarshal(b, &todos); err != nil {
+				} else if err := yaml.NewDecoder(r).Decode(&todos); err != nil {
 					return err
 				}
 				return nil
@@ -199,12 +199,12 @@ func edit(dry bool, filepaths []string) error {
 		return nil
 	}
 	for _, target := range filepaths {
-		b, err := ioutil.ReadFile(path.Join(tempDir, path.Base(target)))
+		r, err := filePathReader(path.Join(tempDir, path.Base(target)))
 		if err != nil {
 			return err
 		}
 		var newTodos []pttodo.Todo
-		if err := yaml.Unmarshal(b, &newTodos); err != nil {
+		if err := yaml.NewDecoder(r).Decode(&newTodos); err != nil {
 			return err
 		}
 		original := originals[target]
@@ -301,13 +301,13 @@ func _edit(dry bool, filepaths []string) error {
 	saveOne := func(filepath string) error {
 		tempFile := path.Join(tempDir, path.Base(filepath))
 		var rootTemp, rootOld pttodo.Root
-		if a, err := ioutil.ReadFile(tempFile); err != nil {
+		if a, err := filePathReader(tempFile); err != nil {
 			return err
-		} else if err := yaml.Unmarshal(a, &rootTemp); err != nil {
+		} else if err := yaml.NewDecoder(a).Decode(&rootTemp); err != nil {
 			return err
-		} else if b, err := ioutil.ReadFile(filepath); err != nil {
+		} else if b, err := filePathReader(filepath); err != nil {
 			return err
-		} else if err := yaml.Unmarshal(b, &rootOld); err != nil {
+		} else if err := yaml.NewDecoder(b).Decode(&rootOld); err != nil {
 			return err
 		} else if rootTemp.Equals(rootOld) {
 			//log.Printf("no changes to %s", filepath)
@@ -533,17 +533,17 @@ func dump(dry bool, writer io.Writer, filepaths []string, tags []string, search,
 }
 
 func filePathReader(path string) (io.Reader, error) {
-	var reader io.Reader
 	if path == "-" {
-		reader = os.Stdin
-	} else {
-		b, err := ioutil.ReadFile(path)
-		if err != nil {
-			return nil, err
-		}
-		reader = bytes.NewReader(b)
+		return os.Stdin, nil
 	}
-	return reader, nil
+	b, err := ioutil.ReadFile(path)
+	if os.IsNotExist(err) {
+		return bytes.NewReader([]byte("{}")), nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return bytes.NewReader(b), nil
 }
 
 func listDir(dname string) ([]string, error) {