Alert unpushed commits when merging a pull request

quiye · samcoe · commit e4b9f7cb8c39 · 2021-01-25T12:04:32.000-08:00
diff --git a/git/git.go b/git/git.go
@@ -180,6 +180,29 @@ func Commits(baseRef, headRef string) ([]*Commit, error) {
 	return commits, nil
 }
 
+func LastCommit() (*Commit, error) {
+	logCmd := GitCommand("-c", "log.ShowSignature=false", "log", "--pretty=format:%H,%s", "-1")
+	output, err := run.PrepareCmd(logCmd).Output()
+	if err != nil {
+		return nil, err
+	}
+
+	lines := outputLines(output)
+	if len(lines) != 1 {
+		return nil, ErrNotOnAnyBranch
+	}
+
+	split := strings.SplitN(lines[0], ",", 2)
+	if len(split) != 2 {
+		return nil, ErrNotOnAnyBranch
+	}
+
+	return &Commit{
+		Sha:   split[0],
+		Title: split[1],
+	}, nil
+}
+
 func CommitBody(sha string) (string, error) {
 	showCmd, err := GitCommand("-c", "log.ShowSignature=false", "show", "-s", "--pretty=format:%b", sha)
 	if err != nil {
diff --git a/pkg/cmd/pr/merge/merge.go b/pkg/cmd/pr/merge/merge.go
@@ -131,6 +131,17 @@ func mergeRun(opts *MergeOptions) error {
 		return err
 	}
 
+	localBranchName, err := git.CurrentBranch()
+	if err == nil {
+		localBranchLastCommit, err := git.LastCommit()
+		if err == nil {
+			if localBranchName == pr.HeadRefName && localBranchLastCommit.Sha != pr.Commits.Nodes[0].Commit.Oid {
+				fmt.Fprintf(opts.IO.ErrOut,
+					"%s Pull request #%d (%s) may have a last commit that is different from local one\n", utils.Yellow("!"), pr.Number, pr.Title)
+			}
+		}
+	}
+
 	if pr.Mergeable == "CONFLICTING" {
 		fmt.Fprintf(opts.IO.ErrOut, "%s Pull request #%d (%s) has conflicts and isn't mergeable\n", cs.Red("!"), pr.Number, pr.Title)
 		return cmdutil.SilentError
diff --git a/pkg/cmd/pr/merge/merge_test.go b/pkg/cmd/pr/merge/merge_test.go
