test: add system tests for creating comment and finding PR by label (#2292)

Towards #300

---------

Signed-off-by: Jeff Ching <[email protected]>

Author: chingor13

internal/github/github.go

@@ -306,6 +306,11 @@ func hasLabel(pr *PullRequest, labelName string) bool {
 
 // FindMergedPullRequestsWithPendingReleaseLabel finds all merged pull requests with the "release:pending" label.
 func (c *Client) FindMergedPullRequestsWithPendingReleaseLabel(ctx context.Context, owner, repo string) ([]*PullRequest, error) {
+	return c.FindMergedPullRequestsWithLabel(ctx, owner, repo, "release:pending")
+}
+
+// FindMergedPullRequestsWithLabel finds all merged pull requests with the "release:pending" label.
+func (c *Client) FindMergedPullRequestsWithLabel(ctx context.Context, owner, repo, label string) ([]*PullRequest, error) {
 	var allPRs []*PullRequest
 	opt := &github.PullRequestListOptions{
 		State: "closed",
@@ -319,7 +324,7 @@ func (c *Client) FindMergedPullRequestsWithPendingReleaseLabel(ctx context.Conte
 			return nil, err
 		}
 		for _, pr := range prs {
-			if !pr.GetMergedAt().IsZero() && hasLabel(pr, "release:pending") {
+			if !pr.GetMergedAt().IsZero() && hasLabel(pr, label) {
 				allPRs = append(allPRs, pr)
 			}
 		}

system_test.go

@@ -102,9 +102,11 @@ func TestPullRequestSystem(t *testing.T) {
 	// Clone a repo
 	// Create a commit and push
 	// Create a pull request
-	// Add a label to the issue
+	// Add a label to the pull request
 	// Fetch labels for the issue and verify
 	// Replace the issue labels
+	// Fetch labels for the issue and verify
+	// Add a comment
 	// Search for the pull request
 	// Fetch the pull request
 	// Close the pull request
@@ -232,6 +234,12 @@ func TestPullRequestSystem(t *testing.T) {
 		t.Fatalf("GetLabels() mismatch (-want + got):\n%s", diff)
 	}
 
+	// Add a comment
+	err = client.CreateIssueComment(t.Context(), createdPullRequest.Number, "some comment body")
+	if err != nil {
+		t.Fatalf("unexpected error in CreateIssueComment() %s", err)
+	}
+
 	// Search for pull requests (this may take a bit of time, so try 5 times)
 	found := false
 	for i := 0; i < 5; i++ {
@@ -241,11 +249,22 @@ func TestPullRequestSystem(t *testing.T) {
 		}
 		for _, pullRequest := range foundPullRequests {
 			// Look for the PR we created
-			if *pullRequest.Number == createdPullRequest.Number {
+			if pullRequest.Number != nil && *pullRequest.Number == createdPullRequest.Number {
 				found = true
+
+				// Expect that we found a comment
+				if pullRequest.Comments == nil {
+					t.Fatal("pull request comments not set")
+				}
+				if *pullRequest.Comments == 0 {
+					t.Fatalf("Expected to have created a comment on the pull request.")
+				}
 				break
 			}
 		}
+		if found {
+			break
+		}
 		delay := time.Duration(2 * time.Second)
 		t.Logf("Retrying in %v...\n", delay)
 		time.Sleep(delay)
@@ -265,14 +284,85 @@ func TestPullRequestSystem(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error in GetPullRequest() %s", err)
 	}
+	if foundPullRequest.Number == nil {
+		t.Fatal("pull request number not set")
+	}
 	if diff := cmp.Diff(*foundPullRequest.Number, createdPullRequest.Number); diff != "" {
 		t.Fatalf("pull request number mismatch (-want + got):\n%s", diff)
 	}
+	if foundPullRequest.State == nil {
+		t.Fatal("pull request state not set")
+	}
 	if diff := cmp.Diff(*foundPullRequest.State, "closed"); diff != "" {
 		t.Fatalf("pull request state mismatch (-want + got):\n%s", diff)
 	}
 }
 
+func TestFindMergedPullRequest(t *testing.T) {
+	if testToken == "" {
+		t.Skip("TEST_GITHUB_TOKEN not set, skipping GitHub integration test")
+	}
+	repoName := "https://github.com/googleapis/librarian"
+	repo, err := github.ParseRemote(repoName)
+	if err != nil {
+		t.Fatalf("unexpected error in ParseRemote() %s", err)
+	}
+
+	for _, test := range []struct {
+		name          string
+		label         string
+		want          int
+		wantErr       bool
+		wantErrSubstr string
+	}{
+		{
+			name:    "existing label",
+			label:   "cla: yes",
+			want:    2210,
+			wantErr: false,
+		},
+		{
+			name:    "non-existing label",
+			label:   "non-existing-label",
+			want:    0,
+			wantErr: false,
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			client := github.NewClient(testToken, repo)
+			prs, err := client.FindMergedPullRequestsWithLabel(t.Context(), repo.Owner, repo.Name, test.label)
+			if test.wantErr {
+				if err == nil {
+					t.Fatalf("FindMergedPullRequestsWithLabel() err = nil, want error containing %q", test.wantErrSubstr)
+				} else if !strings.Contains(err.Error(), test.wantErrSubstr) {
+					t.Errorf("FindMergedPullRequestsWithLabel() err = %v, want error containing %q", err, test.wantErrSubstr)
+				}
+				return
+			}
+			if err != nil {
+				t.Errorf("FindMergedPullRequestsWithLabel() err = %v, want nil", err)
+			}
+			if test.want == 0 {
+				// expect to not find any
+				if len(prs) > 0 {
+					t.Fatalf("FindMergedPullRequestWithLabel() expected to not find any PRs, found %d", len(prs))
+				}
+			} else {
+				found := false
+				for _, pr := range prs {
+					t.Logf("Found PR %d", *pr.Number)
+					if pr.Number != nil && *pr.Number == test.want {
+						found = true
+					}
+				}
+				if !found {
+					t.Fatalf("FindMergedPullRequestsWithLabel() expected to find PR #%d", test.want)
+				}
+			}
+		})
+	}
+}
+
 func TestCreateTag(t *testing.T) {
 	if testToken == "" {
 		t.Skip("TEST_GITHUB_TOKEN not set, skipping GitHub integration test")