feat: add release notes in release pull request (#1905)

Fixes #1899

Author: JoeWang1127

internal/librarian/command_test.go

@@ -1135,7 +1135,7 @@ func TestCommitAndPush(t *testing.T) {
 			commit: true,
 		},
 		{
-			name: "create a pull request",
+			name: "create a generate pull request",
 			setupMockRepo: func(t *testing.T) gitrepo.Repository {
 				remote := git.NewRemote(memory.NewStorage(), &gogitConfig.RemoteConfig{
 					Name: "origin",
@@ -1158,6 +1158,30 @@ func TestCommitAndPush(t *testing.T) {
 			prType: "generate",
 			push:   true,
 		},
+		{
+			name: "create a release pull request",
+			setupMockRepo: func(t *testing.T) gitrepo.Repository {
+				remote := git.NewRemote(memory.NewStorage(), &gogitConfig.RemoteConfig{
+					Name: "origin",
+					URLs: []string{"https://github.com/googleapis/librarian.git"},
+				})
+				status := make(git.Status)
+				status["file.txt"] = &git.FileStatus{Worktree: git.Modified}
+				return &MockRepository{
+					Dir:          t.TempDir(),
+					AddAllStatus: status,
+					RemotesValue: []*git.Remote{remote},
+				}
+			},
+			setupMockClient: func(t *testing.T) GitHubClient {
+				return &mockGitHubClient{
+					createdPR: &github.PullRequestMetadata{Number: 123, Repo: &github.Repository{Owner: "test-owner", Name: "test-repo"}},
+				}
+			},
+			state:  &config.LibrarianState{},
+			prType: "release",
+			push:   true,
+		},
 		{
 			name: "No GitHub Remote",
 			setupMockRepo: func(t *testing.T) gitrepo.Repository {
@@ -1360,6 +1384,7 @@ func TestCommitAndPush(t *testing.T) {
 				commitMessage: "",
 				prType:        test.prType,
 			}
+
 			err := commitAndPush(context.Background(), commitInfo)
 
 			if test.wantErr {

internal/librarian/release_init.go

@@ -110,7 +110,7 @@ func (r *initRunner) run(ctx context.Context) error {
 		state:         r.state,
 		repo:          r.repo,
 		ghClient:      r.ghClient,
-		commitMessage: "",
+		commitMessage: "chore: create a release",
 		prType:        release,
 	}
 	if err := commitAndPush(ctx, commitInfo); err != nil {

internal/librarian/release_notes.go

@@ -64,19 +64,29 @@ var (
 
 	releaseNotesTemplate = template.Must(template.New("releaseNotes").Funcs(template.FuncMap{
 		"shortSHA": shortSHA,
-	}).Parse(`## [{{.NewVersion}}]({{"https://github.com/"}}{{.Repo.Owner}}/{{.Repo.Name}}/compare/{{.PreviousTag}}...{{.NewTag}}) ({{.Date}})
-{{- range .Sections -}}
+	}).Parse(`Librarian Version: {{.LibrarianVersion}}
+Language Image: {{.ImageVersion}}
+
+{{- range .NoteSections -}}
+{{ $noteSection := . }}
+<details><summary>{{.LibraryID}}: {{.NewVersion}}</summary>
+
+## [{{.NewVersion}}]({{"https://github.com/"}}{{.RepoOwner}}/{{.RepoName}}/compare/{{.PreviousTag}}...{{.NewTag}}) ({{.Date}})
+{{- range .CommitSections -}}
 {{- if .Commits -}}
-{{- if .Heading}}
+{{- if .Heading }}
 
 ### {{.Heading}}
-{{end}}
-
+{{ end }}
 {{- range .Commits -}}
-* {{.Description}} ([{{shortSHA .SHA}}]({{"https://github.com/"}}{{$.Repo.Owner}}/{{$.Repo.Name}}/commit/{{.SHA}}))
-{{- end -}}
-{{- end -}}
-{{- end -}}`))
+* {{.Description}} ([{{shortSHA .SHA}}]({{"https://github.com/"}}{{$noteSection.RepoOwner}}/{{$noteSection.RepoName}}/commit/{{.SHA}}))
+{{- end }}
+{{- end }}
+{{- end }}
+</details>
+
+{{ end }}
+`))
 
 	genBodyTemplate = template.Must(template.New("genBody").Funcs(template.FuncMap{
 		"shortSHA": shortSHA,
@@ -121,6 +131,28 @@ type generationPRBody struct {
 	FailedLibraries  []string
 }
 
+type releaseNote struct {
+	LibrarianVersion string
+	ImageVersion     string
+	NoteSections     []*releaseNoteSection
+}
+
+type releaseNoteSection struct {
+	RepoOwner      string
+	RepoName       string
+	LibraryID      string
+	PreviousTag    string
+	NewTag         string
+	NewVersion     string
+	Date           string
+	CommitSections []*commitSection
+}
+
+type commitSection struct {
+	Heading string
+	Commits []*conventionalcommits.ConventionalCommit
+}
+
 // formatGenerationPRBody creates the body of a generation pull request.
 // Only consider libraries whose ID appears in idToCommits.
 func formatGenerationPRBody(repo gitrepo.Repository, state *config.LibrarianState, idToCommits map[string]string, failedLibraries []string) (string, error) {
@@ -207,46 +239,49 @@ func findLatestGenerationCommit(repo gitrepo.Repository, state *config.Librarian
 
 // formatReleaseNotes generates the body for a release pull request.
 func formatReleaseNotes(repo gitrepo.Repository, state *config.LibrarianState) (string, error) {
-	var body bytes.Buffer
-
 	librarianVersion := cli.Version()
-	fmt.Fprintf(&body, "Librarian Version: %s\n", librarianVersion)
-	fmt.Fprintf(&body, "Language Image: %s\n\n", state.Image)
-
+	var releaseSections []*releaseNoteSection
 	for _, library := range state.Libraries {
 		if !library.ReleaseTriggered {
 			continue
 		}
 
-		notes, newVersion, err := formatLibraryReleaseNotes(repo, library)
+		section, err := formatLibraryReleaseNotes(repo, library)
 		if err != nil {
 			return "", fmt.Errorf("failed to format release notes for library %s: %w", library.ID, err)
 		}
-		fmt.Fprintf(&body, "<details><summary>%s: %s</summary>\n\n", library.ID, newVersion)
+		releaseSections = append(releaseSections, section)
+	}
 
-		body.WriteString(notes)
-		body.WriteString("\n\n</details>")
+	data := &releaseNote{
+		LibrarianVersion: librarianVersion,
+		ImageVersion:     state.Image,
+		NoteSections:     releaseSections,
+	}
 
-		body.WriteString("\n")
+	var out bytes.Buffer
+	if err := releaseNotesTemplate.Execute(&out, data); err != nil {
+		return "", fmt.Errorf("error executing template: %w", err)
 	}
-	return body.String(), nil
+
+	return strings.TrimSpace(out.String()), nil
 }
 
 // formatLibraryReleaseNotes generates release notes in Markdown format for a single library.
 // It returns the generated release notes and the new version string.
-func formatLibraryReleaseNotes(repo gitrepo.Repository, library *config.LibraryState) (string, string, error) {
+func formatLibraryReleaseNotes(repo gitrepo.Repository, library *config.LibraryState) (*releaseNoteSection, error) {
 	ghRepo, err := github.FetchGitHubRepoFromRemote(repo)
 	if err != nil {
-		return "", "", fmt.Errorf("failed to fetch github repo from remote: %w", err)
+		return nil, fmt.Errorf("failed to fetch github repo from remote: %w", err)
 	}
 	previousTag := formatTag(library, "")
 	commits, err := GetConventionalCommitsSinceLastRelease(repo, library)
 	if err != nil {
-		return "", "", fmt.Errorf("failed to get conventional commits for library %s: %w", library.ID, err)
+		return nil, fmt.Errorf("failed to get conventional commits for library %s: %w", library.ID, err)
 	}
 	newVersion, err := NextVersion(commits, library.Version, "")
 	if err != nil {
-		return "", "", fmt.Errorf("failed to get next version for library %s: %w", library.ID, err)
+		return nil, fmt.Errorf("failed to get next version for library %s: %w", library.ID, err)
 	}
 	newTag := formatTag(library, newVersion)
 
@@ -255,43 +290,29 @@ func formatLibraryReleaseNotes(repo gitrepo.Repository, library *config.LibraryS
 		commitsByType[commit.Type] = append(commitsByType[commit.Type], commit)
 	}
 
-	type releaseNoteSection struct {
-		Heading string
-		Commits []*conventionalcommits.ConventionalCommit
-	}
-	var sections []releaseNoteSection
+	var sections []*commitSection
 	// Group commits by type, according to commitTypeOrder, to be used in the release notes.
 	for _, ct := range commitTypeOrder {
 		displayName, headingOK := commitTypeToHeading[ct]
 		typedCommits, commitsOK := commitsByType[ct]
 		if headingOK && commitsOK {
-			sections = append(sections, releaseNoteSection{
+			sections = append(sections, &commitSection{
 				Heading: displayName,
 				Commits: typedCommits,
 			})
 		}
 	}
 
-	var out bytes.Buffer
-	data := struct {
-		NewVersion  string
-		PreviousTag string
-		NewTag      string
-		Repo        *github.Repository
-		Date        string
-		Sections    []releaseNoteSection
-	}{
-		NewVersion:  newVersion,
-		PreviousTag: previousTag,
-		NewTag:      newTag,
-		Repo:        ghRepo,
-		Date:        time.Now().Format("2006-01-02"),
-		Sections:    sections,
-	}
-	if err := releaseNotesTemplate.Execute(&out, data); err != nil {
-		// This should not happen, as the template is valid and the data is structured correctly.
-		return "", "", fmt.Errorf("error executing template: %v", err)
+	section := &releaseNoteSection{
+		RepoOwner:      ghRepo.Owner,
+		RepoName:       ghRepo.Name,
+		LibraryID:      library.ID,
+		NewVersion:     newVersion,
+		PreviousTag:    previousTag,
+		NewTag:         newTag,
+		Date:           time.Now().Format("2006-01-02"),
+		CommitSections: sections,
 	}
 
-	return strings.TrimSpace(out.String()), newVersion, nil
+	return section, nil
 }

internal/librarian/release_notes_test.go

@@ -523,7 +523,6 @@ func TestFormatReleaseNotes(t *testing.T) {
 			},
 			wantReleaseNote: fmt.Sprintf(`Librarian Version: %s
 Language Image: go:1.21
-
 <details><summary>my-library: 1.1.0</summary>
 
 ## [1.1.0](https://github.com/owner/repo/compare/my-library-1.0.0...my-library-1.1.0) (%s)
@@ -533,9 +532,7 @@ Language Image: go:1.21
 
 ### Bug Fixes
 * a bug fix ([fedcba0](https://github.com/owner/repo/commit/fedcba0987654321000000000000000000000000))
-
-</details>
-`,
+</details>`,
 				librarianVersion, today),
 		},
 		{
@@ -572,24 +569,22 @@ Language Image: go:1.21
 			},
 			wantReleaseNote: fmt.Sprintf(`Librarian Version: %s
 Language Image: go:1.21
-
 <details><summary>lib-a: 1.1.0</summary>
 
 ## [1.1.0](https://github.com/owner/repo/compare/lib-a-1.0.0...lib-a-1.1.0) (%s)
 
 ### Features
 * feature for a ([1234567](https://github.com/owner/repo/commit/1234567890abcdef000000000000000000000000))
-
 </details>
+
+
 <details><summary>lib-b: 2.0.1</summary>
 
 ## [2.0.1](https://github.com/owner/repo/compare/lib-b-2.0.0...lib-b-2.0.1) (%s)
 
 ### Bug Fixes
 * fix for b ([fedcba0](https://github.com/owner/repo/commit/fedcba0987654321000000000000000000000000))
-
-</details>
-`,
+</details>`,
 				librarianVersion, today, today),
 		},
 		{
@@ -619,16 +614,13 @@ Language Image: go:1.21
 			},
 			wantReleaseNote: fmt.Sprintf(`Librarian Version: %s
 Language Image: go:1.21
-
 <details><summary>my-library: 1.1.0</summary>
 
 ## [1.1.0](https://github.com/owner/repo/compare/my-library-1.0.0...my-library-1.1.0) (%s)
 
 ### Features
 * new feature ([1234567](https://github.com/owner/repo/commit/1234567890abcdef000000000000000000000000))
-
-</details>
-`,
+</details>`,
 				librarianVersion, today),
 		},
 		{
@@ -638,7 +630,7 @@ Language Image: go:1.21
 				Libraries: []*config.LibraryState{},
 			},
 			repo:            &MockRepository{},
-			wantReleaseNote: fmt.Sprintf("Librarian Version: %s\nLanguage Image: go:1.21\n\n", librarianVersion),
+			wantReleaseNote: fmt.Sprintf("Librarian Version: %s\nLanguage Image: go:1.21", librarianVersion),
 		},
 		{
 			name: "error getting commits",