From c7dd9edd57c6183fa89510cdafc738fd497acdca Mon Sep 17 00:00:00 2001
From: Azeem Sajid <azeem.sajid@gmail.com>
Date: Wed, 29 Jan 2025 16:39:56 +0500
Subject: [PATCH] [gh workflow run] Improve error handling for `--ref` flag

---
 pkg/cmd/workflow/run/run.go       | 14 +++++++++-----
 pkg/cmd/workflow/shared/shared.go |  5 ++++-
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/pkg/cmd/workflow/run/run.go b/pkg/cmd/workflow/run/run.go
index b7ab53098..3ba64ad4a 100644
--- a/pkg/cmd/workflow/run/run.go
+++ b/pkg/cmd/workflow/run/run.go
@@ -262,11 +262,15 @@ func runRun(opts *RunOptions) error {
 
 	ref := opts.Ref
 
-	if ref == "" {
-		ref, err = api.RepoDefaultBranch(client, repo)
-		if err != nil {
-			return fmt.Errorf("unable to determine default branch for %s: %w", ghrepo.FullName(repo), err)
-		}
+	defaultBranch, err := api.RepoDefaultBranch(client, repo)
+	if err != nil {
+		return fmt.Errorf("unable to determine default branch for %s: %w", ghrepo.FullName(repo), err)
+	}
+
+	if ref != "" && ref != defaultBranch {
+		return fmt.Errorf("ref %s is not the default branch, and workflows must be on the default branch to be triggered by workflow_dispatch", ref)
+	} else {
+		ref = defaultBranch
 	}
 
 	states := []shared.WorkflowState{shared.Active}
diff --git a/pkg/cmd/workflow/shared/shared.go b/pkg/cmd/workflow/shared/shared.go
index db6b3ab12..61511ed7d 100644
--- a/pkg/cmd/workflow/shared/shared.go
+++ b/pkg/cmd/workflow/shared/shared.go
@@ -131,7 +131,10 @@ func FindWorkflow(client *api.Client, repo ghrepo.Interface, workflowSelector st
 	if _, err := strconv.Atoi(workflowSelector); err == nil || isWorkflowFile(workflowSelector) {
 		workflow, err := getWorkflowByID(client, repo, workflowSelector)
 		if err != nil {
-			return nil, err
+			var httpErr api.HTTPError
+			if errors.As(err, &httpErr) && httpErr.StatusCode == 404 {
+				return nil, fmt.Errorf("workflow %s not found on the default branch", workflowSelector)
+			}
 		}
 		return []Workflow{*workflow}, nil
 	}