lab: Add assign reviewer functionality

The 'mr create' and 'mr edit' commands have the ability to assign and
unassign GitLab users to Merge Requests.  Add similar functionality to
allow adding GitLab users as Reviewers of Merge Requests.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>

cmd/mr_create.go

@@ -34,6 +34,7 @@ var mrCreateCmd = &cobra.Command{
 func init() {
 	mrCreateCmd.Flags().StringArrayP("message", "m", []string{}, "use the given <msg>; multiple -m are concatenated as separate paragraphs")
 	mrCreateCmd.Flags().StringSliceP("assignee", "a", []string{}, "set assignee by username; can be specified multiple times for multiple assignees")
+	mrCreateCmd.Flags().StringSliceP("reviewer", "r", []string{}, "set reviewer by username; can be specified multiple times for multiple reviewers")
 	mrCreateCmd.Flags().StringSliceP("label", "l", []string{}, "add label <label>; can be specified multiple times for multiple labels")
 	mrCreateCmd.Flags().BoolP("remove-source-branch", "d", false, "remove source branch from remote after merge")
 	mrCreateCmd.Flags().BoolP("squash", "s", false, "squash commits when merging")
@@ -114,6 +115,11 @@ func runMRCreate(cmd *cobra.Command, args []string) {
 	if err != nil {
 		log.Fatal(err)
 	}
+	reviewers, err := cmd.Flags().GetStringSlice("reviewer")
+	if err != nil {
+		log.Fatal(err)
+	}
+
 	filename, err := cmd.Flags().GetString("file")
 	if err != nil {
 		log.Fatal(err)
@@ -282,6 +288,7 @@ func runMRCreate(cmd *cobra.Command, args []string) {
 		Title:              &title,
 		Description:        &body,
 		AssigneeIDs:        getUserIDs(assignees),
+		ReviewerIDs:        getUserIDs(reviewers),
 		RemoveSourceBranch: &removeSourceBranch,
 		Squash:             &squash,
 		AllowCollaboration: &allowCollaboration,

cmd/mr_edit.go

@@ -99,6 +99,18 @@ lab MR edit <id>:<comment_id>                   # update a comment on MR`,
 			log.Fatal(err)
 		}
 
+		// get the reviewers to add
+		reviewers, err := cmd.Flags().GetStringSlice("review")
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		// get the reviewers to remove
+		unreviewers, err := cmd.Flags().GetStringSlice("unreview")
+		if err != nil {
+			log.Fatal(err)
+		}
+
 		filename, err := cmd.Flags().GetString("file")
 		if err != nil {
 			log.Fatal(err)
@@ -124,6 +136,12 @@ lab MR edit <id>:<comment_id>                   # update a comment on MR`,
 			log.Fatal(err)
 		}
 
+		currentReviewers := mrGetCurrentReviewers(mr)
+		reviewerIDs, reviewersChanged, err := getUpdateUsers(currentReviewers, reviewers, unreviewers)
+		if err != nil {
+			log.Fatal(err)
+		}
+
 		milestoneName, err := cmd.Flags().GetString("milestone")
 		if err != nil {
 			log.Fatal(err)
@@ -233,6 +251,10 @@ lab MR edit <id>:<comment_id>                   # update a comment on MR`,
 			opts.AssigneeIDs = assigneeIDs
 		}
 
+		if reviewersChanged {
+			opts.ReviewerIDs = reviewerIDs
+		}
+
 		if updateMilestone {
 			opts.MilestoneID = &milestoneID
 		}
@@ -261,6 +283,18 @@ func mrGetCurrentAssignees(mr *gitlab.MergeRequest) []string {
 	return currentAssignees
 }
 
+// mrGetCurrentReviewers returns a string slice of the current reviewers'
+// usernames
+func mrGetCurrentReviewers(mr *gitlab.MergeRequest) []string {
+	currentReviewers := make([]string, len(mr.Reviewers))
+	if len(mr.Reviewers) > 0 && mr.Reviewers[0].Username != "" {
+		for i, a := range mr.Reviewers {
+			currentReviewers[i] = a.Username
+		}
+	}
+	return currentReviewers
+}
+
 // getBranchName considers the possible ambiguity of different branch names
 func getBranchName(project, branch string) (string, error) {
 	opts := &gitlab.ListBranchesOptions{
@@ -313,6 +347,8 @@ func init() {
 	mrEditCmd.Flags().Bool("force-linebreak", false, "append 2 spaces to the end of each line to force markdown linebreaks")
 	mrEditCmd.Flags().Bool("draft", false, "mark the merge request as draft")
 	mrEditCmd.Flags().Bool("ready", false, "mark the merge request as ready")
+	mrEditCmd.Flags().StringSliceP("review", "r", []string{}, "add an reviewer by username")
+	mrEditCmd.Flags().StringSliceP("unreview", "", []string{}, "remove an reviewer by username")
 	mrEditCmd.Flags().SortFlags = false
 
 	mrCmd.AddCommand(mrEditCmd)