mr checkout: Add --force option

Users have reported a minor annoyance with 'lab mr checkout':

- reviewer checkouts out MR for review
lab mr checkout 3
- reviewer requests changes
- author makes changes
- reviewer checkouts out MR for re-review
lab mr checkout 3

and is returned a "ERROR: mr 3 branch branchname already
exists."

In most cases that I can think of the person checking out the MR
wants the latest version of the the code in the MR, not old code.  It
would be convenient to have a --force option that would delete and
overwrite the existing MR branch.

Add 'lab mr checkout --force' option that overwrites an existing MR branch
checkout.

Signed-off-by: Prarit Bhargava <[email protected]>

cmd/mr_checkout.go

@@ -17,6 +17,7 @@ import (
 // mrCheckoutConfig holds configuration values for calls to lab mr checkout
 type mrCheckoutConfig struct {
 	branch string
+	force  bool
 	track  bool
 }
 
@@ -80,8 +81,14 @@ var checkoutCmd = &cobra.Command{
 		}
 
 		if err := git.New("show-ref", "--verify", "--quiet", "refs/heads/"+fetchToRef).Run(); err == nil {
-			fmt.Println("ERROR: mr", mrID, "branch", fetchToRef, "already exists.")
-			os.Exit(1)
+			if mrCheckoutCfg.force {
+				if err := git.New("branch", "-D", mrCheckoutCfg.branch).Run(); err != nil {
+					log.Fatal(err)
+				}
+			} else {
+				fmt.Println("ERROR: mr", mrID, "branch", fetchToRef, "already exists.")
+				os.Exit(1)
+			}
 		}
 
 		// https://docs.gitlab.com/ce/user/project/merge_requests/#checkout-merge-requests-locally
@@ -111,6 +118,7 @@ func init() {
 	checkoutCmd.Flags().BoolVarP(&mrCheckoutCfg.track, "track", "t", false, "set checked out branch to track mr author remote branch, adds remote if needed")
 	// useHTTP is defined in "project_create.go"
 	checkoutCmd.Flags().BoolVar(&useHTTP, "http", false, "checkout using HTTP protocol instead of SSH")
+	checkoutCmd.Flags().BoolVarP(&mrCheckoutCfg.force, "force", "f", false, "force branch checkout and override existing branch")
 	mrCmd.AddCommand(checkoutCmd)
 	carapace.Gen(checkoutCmd).PositionalCompletion(
 		carapace.ActionCallback(func(c carapace.Context) carapace.Action {

cmd/mr_checkout_test.go

@@ -127,7 +127,7 @@ func Test_mrCheckoutCmdRunWithDifferentName(t *testing.T) {
 	require.Contains(t, eLog, "54fd49a2ac60aeeef5ddc75efecd49f85f7ba9b0")
 }
 
-func Test_mrDoubleCheckoutCmdRun(t *testing.T) {
+func Test_mrDoubleCheckoutFailCmdRun(t *testing.T) {
 	repo := copyTestRepo(t)
 
 	// make sure the branch does not exist
@@ -153,3 +153,38 @@ func Test_mrDoubleCheckoutCmdRun(t *testing.T) {
 	}
 	require.Contains(t, eLog, "ERROR: mr 1 branch mrtest already exists")
 }
+
+func Test_mrDoubleCheckoutForceRun(t *testing.T) {
+	repo := copyTestRepo(t)
+
+	// make sure the branch does not exist
+	cmd := exec.Command("git", "branch", "-D", "mrtest")
+	cmd.Dir = repo
+	cmd.CombinedOutput()
+
+	first := exec.Command(labBinaryPath, "mr", "checkout", "1")
+	first.Dir = repo
+	b, err := first.CombinedOutput()
+	if err != nil {
+		t.Log(string(b))
+		t.Fatal(err)
+	}
+
+	changeBranch := exec.Command("git", "checkout", "master")
+	changeBranch.Dir = repo
+	c, err := changeBranch.CombinedOutput()
+	if err != nil {
+		t.Log(string(c))
+		t.Fatal(err)
+	}
+
+	second := exec.Command(labBinaryPath, "mr", "checkout", "1", "--force")
+	second.Dir = repo
+	log, err := second.CombinedOutput()
+	eLog := string(log)
+	if err != nil {
+		t.Log(eLog)
+		t.Fatal(err)
+	}
+	require.Contains(t, eLog, "Deleted branch mrtest")
+}