refactor(internal/librarianops/generate): move github functions to its own file

internal/librarianops/generate.go

@@ -105,7 +105,7 @@ func processRepo(ctx context.Context, repoName, repoDir, librarianBin string, ve
 				err = cerr
 			}
 		}()
-		if err := cloneRepo(ctx, repoDir, repoName); err != nil {
+		if err := cloneRepoInDir(ctx, repoName, repoDir); err != nil {
 			return err
 		}
 	}
@@ -117,8 +117,7 @@ func processRepo(ctx context.Context, repoName, repoDir, librarianBin string, ve
 		return fmt.Errorf("failed to change directory to %q: %w", repoDir, err)
 	}
 	defer os.Chdir(originalWD)
-
-	if err := createBranch(ctx, time.Now()); err != nil {
+	if err := createBranch(ctx, generateBranchName(branchPrefix, time.Now())); err != nil {
 		return err
 	}
 	cfg, err := yaml.Read[config.Config]("librarian.yaml")
@@ -157,48 +156,32 @@ func processRepo(ctx context.Context, repoName, repoDir, librarianBin string, ve
 			return err
 		}
 	}
-	if err := commitChanges(ctx); err != nil {
+	if err := commitChanges(ctx, commitTitle); err != nil {
 		return err
 	}
 	if repoName != repoFake {
-		if err := pushBranch(ctx); err != nil {
+		if err := pushChanges(ctx); err != nil {
 			return err
 		}
-		if err := createPR(ctx, repoName); err != nil {
+		if err := createPR(ctx, createGithubDetails(repoName)); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func cloneRepo(ctx context.Context, repoDir, repoName string) error {
-	return command.Run(ctx, "gh", "repo", "clone", fmt.Sprintf("googleapis/%s", repoName), repoDir)
-}
-
-func createBranch(ctx context.Context, now time.Time) error {
-	branchName := fmt.Sprintf("%s%s", branchPrefix, now.UTC().Format("20060102T150405Z"))
-	return command.Run(ctx, "git", "checkout", "-b", branchName)
-}
-
-func commitChanges(ctx context.Context) error {
-	if err := command.Run(ctx, "git", "add", "."); err != nil {
-		return err
-	}
-	return command.Run(ctx, "git", "commit", "-m", commitTitle)
-}
-
-func pushBranch(ctx context.Context) error {
-	return command.Run(ctx, "git", "push", "-u", "origin", "HEAD")
-}
-
-func createPR(ctx context.Context, repoName string) error {
+func createGithubDetails(repoName string) GithubDetails {
 	sources := "googleapis"
 	if repoName == repoRust {
 		sources = "googleapis and discovery-artifact-manager"
 	}
 	title := fmt.Sprintf("chore: update %s and regenerate", sources)
 	body := fmt.Sprintf("Update %s to the latest commit and regenerate all client libraries.", sources)
-	return command.Run(ctx, "gh", "pr", "create", "--title", title, "--body", body)
+	return GithubDetails{
+		PrTitle:    title,
+		PrBody:     body,
+		BranchName: generateBranchName(branchPrefix, time.Now()),
+	}
 }
 
 func runCargoUpdate(ctx context.Context) error {

internal/librarianops/github_utils.go

@@ -0,0 +1,76 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package librarianops
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/googleapis/librarian/internal/command"
+)
+
+var runCommand = command.Run
+
+// uploadToGithub creates a branch, commits changes, pushes the changes, and creates a PR with the given details.
+func uploadToGithub(ctx context.Context, githubDetails GithubDetails) error {
+	if err := createBranch(ctx, githubDetails.BranchName); err != nil {
+		return err
+	}
+	if err := commitChanges(ctx, githubDetails.PrTitle); err != nil {
+		return err
+	}
+	if err := pushChanges(ctx); err != nil {
+		return err
+	}
+	if err := createPR(ctx, githubDetails); err != nil {
+		return err
+	}
+	return nil
+}
+
+func cloneRepoInDir(ctx context.Context, repoName string, repoDir string) error {
+	return runCommand(ctx, "gh", "repo", "clone", fmt.Sprintf("googleapis/%s", repoName), repoDir)
+}
+
+func generateBranchName(prefix string, time time.Time) string {
+	return fmt.Sprintf("%s%s", prefix, time.UTC().Format("20060102T150405Z"))
+}
+
+func createBranch(ctx context.Context, branchName string) error {
+	return runCommand(ctx, "git", "checkout", "-b", branchName)
+}
+
+func commitChanges(ctx context.Context, commitTitle string) error {
+	if err := runCommand(ctx, "git", "add", "."); err != nil {
+		return err
+	}
+	return runCommand(ctx, "git", "commit", "-m", commitTitle)
+}
+
+func pushChanges(ctx context.Context) error {
+	return runCommand(ctx, "git", "push", "-u", "origin", "HEAD")
+}
+
+// GithubDetails contains the details for the github changes to be made.
+type GithubDetails struct {
+	PrTitle    string
+	PrBody     string
+	BranchName string
+}
+
+func createPR(ctx context.Context, githubDetails GithubDetails) error {
+	return runCommand(ctx, "gh", "pr", "create", "--title", githubDetails.PrTitle, "--body", githubDetails.PrBody)
+}