Add coauthor (#2)

Add co-author to commits

Add addCoAuthor command for commits

- Implement the `addCoAuthor` command to add co-authors to commits.
- Utilize suggestions helpers to populate author names from the suggestions list.
- Added command to gui at `LocalCommitsController`.

This commit introduces the `addCoAuthor` command, which allows users to easily add co-authors to their commits. The co-author names are populated from the suggestions list, minimizing the chances of user input errors. The co-authors are added using the Co-authored-by metadata format recognized by GitHub and GitLab.

pkg/commands/git_commands/commit.go

@@ -38,6 +38,22 @@ func (self *CommitCommands) SetAuthor(value string) error {
 	return self.cmd.New(cmdArgs).Run()
 }
 
+// Add a commit's coauthor using Github/Gitlab Co-authored-by metadata. Value is expected to be of the form 'Name <Email>'
+func (self *CommitCommands) AddCoAuthor(sha string, value string) error {
+	message, err := self.GetCommitMessage(sha)
+	if err != nil {
+		return err
+	}
+
+	message = message + fmt.Sprintf("\nCo-authored-by: %s", value)
+
+	cmdArgs := NewGitCmd("commit").
+		Arg("--allow-empty", "--amend", "--only", "-m", message).
+		ToArgv()
+
+	return self.cmd.New(cmdArgs).Run()
+}
+
 // ResetToCommit reset to commit
 func (self *CommitCommands) ResetToCommit(sha string, strength string, envVars []string) error {
 	cmdArgs := NewGitCmd("reset").Arg("--"+strength, sha).ToArgv()

pkg/commands/git_commands/rebase.go

@@ -79,6 +79,12 @@ func (self *RebaseCommands) SetCommitAuthor(commits []*models.Commit, index int,
 	})
 }
 
+func (self *RebaseCommands) AddCommitCoAuthor(commits []*models.Commit, index int, value string) error {
+	return self.GenericAmend(commits, index, func() error {
+		return self.commit.AddCoAuthor(commits[index].Sha, value)
+	})
+}
+
 func (self *RebaseCommands) GenericAmend(commits []*models.Commit, index int, f func() error) error {
 	if models.IsHeadCommit(commits, index) {
 		// we've selected the top commit so no rebase is required