chore: GetLabels to paginate the GitHub responses (#1928)

Author: suztomo

internal/github/github.go

@@ -166,15 +166,24 @@ func (c *Client) CreatePullRequest(ctx context.Context, repo *Repository, remote
 // GetLabels fetches the labels for an issue.
 func (c *Client) GetLabels(ctx context.Context, number int) ([]string, error) {
 	slog.Info("Getting labels", "number", number)
-	labels, _, err := c.Issues.ListLabelsByIssue(ctx, c.repo.Owner, c.repo.Name, number, nil)
-	if err != nil {
-		return nil, err
+	var allLabels []string
+	opts := &github.ListOptions{
+		PerPage: 100,
 	}
-	var labelNames []string
-	for _, label := range labels {
-		labelNames = append(labelNames, *label.Name)
+	for {
+		labels, resp, err := c.Issues.ListLabelsByIssue(ctx, c.repo.Owner, c.repo.Name, number, opts)
+		if err != nil {
+			return nil, err
+		}
+		for _, label := range labels {
+			allLabels = append(allLabels, *label.Name)
+		}
+		if resp.NextPage == 0 {
+			break
+		}
+		opts.Page = resp.NextPage
 	}
-	return labelNames, nil
+	return allLabels, nil
 }
 
 // ReplaceLabels replaces all labels for an issue.

internal/github/github_test.go

@@ -560,6 +560,19 @@ func TestGetLabels(t *testing.T) {
 			issueNum:   7,
 			wantLabels: []string{"label1", "label2"},
 		},
+		{
+			name: "get labels with pagination",
+			handler: func(w http.ResponseWriter, r *http.Request) {
+				if r.URL.Query().Get("page") == "2" {
+					fmt.Fprint(w, `[{"name": "label3"}]`)
+					return
+				}
+				w.Header().Set("Link", `<http://`+r.Host+`/repos/owner/repo/issues/7/labels?page=2>; rel="next"`)
+				fmt.Fprint(w, `[{"name": "label1"}, {"name": "label2"}]`)
+			},
+			issueNum:   7,
+			wantLabels: []string{"label1", "label2", "label3"},
+		},
 		{
 			name:          "GitHub API error",
 			handler:       func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusInternalServerError) },