edit_common: add func to get title and body from file

Move the code being used in mr_create for the -F flag, to get the MR title
and description from a file, to edit_common, letting other commands to use
the same functionality.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>

cmd/edit_common.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"bufio"
+	"os"
 	"strings"
 
 	"github.com/zaquestion/lab/internal/git"
@@ -40,8 +42,9 @@ func getUpdateAssignees(currentAssignees []string, assignees []string, unassigne
 	return assigneeIDs, assigneesChanged, nil
 }
 
-// editGetTitleDescription returns a title and description based on the current
-// issue title and description and various flags from the command line
+// editGetTitleDescription returns a title and description based on the
+// current issue title and description and various flags from the command
+// line
 func editGetTitleDescription(title string, body string, msgs []string, nFlag int) (string, string, error) {
 	if len(msgs) > 0 {
 		title = msgs[0]
@@ -66,3 +69,29 @@ func editGetTitleDescription(title string, body string, msgs []string, nFlag int
 	}
 	return git.Edit("EDIT", text)
 }
+
+// editGetTitleDescFromFile returns the new title and description based on
+// the content of a file. The first line is considered the title, the
+// remaining is the description.
+func editGetTitleDescFromFile(filename string) (string, string, error) {
+	var title, body string
+
+	file, err := os.Open(filename)
+	if err != nil {
+		return "", "", nil
+	}
+	defer file.Close()
+
+	fileScan := bufio.NewScanner(file)
+	fileScan.Split(bufio.ScanLines)
+
+	// The first line in the file is the title.
+	fileScan.Scan()
+	title = fileScan.Text()
+
+	for fileScan.Scan() {
+		body = body + fileScan.Text() + "\n"
+	}
+
+	return title, body, nil
+}

cmd/mr_create.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"bufio"
 	"bytes"
 	"fmt"
 	"log"
@@ -192,23 +191,10 @@ func runMRCreate(cmd *cobra.Command, args []string) {
 			log.Fatal("option -F cannot be combined with -m/-c")
 		}
 
-		file, err := os.Open(filename)
+		title, body, err = editGetTitleDescFromFile(filename)
 		if err != nil {
 			log.Fatal(err)
 		}
-
-		fileScan := bufio.NewScanner(file)
-		fileScan.Split(bufio.ScanLines)
-
-		// The first line in the file is the title.
-		fileScan.Scan()
-		title = fileScan.Text()
-
-		for fileScan.Scan() {
-			body = body + fileScan.Text() + "\n"
-		}
-
-		file.Close()
 	} else if len(msgs) > 0 {
 		if coverLetterFormat {
 			log.Fatal("option -m cannot be combined with -c/-F")