feat: implement createBranchAndCommit function with tests for branch creation and committing changes

Author: CasperKristiansson

docs/tasks.md

@@ -145,7 +145,7 @@ Use Context7 MCP for up to date documentation.
 
 ## 5) PR creation and safety
 
-18. [ ] **Git branch and commit**
+18. [x] **Git branch and commit**
         Create `chore/bump-python-<track>`. Commit updated files.
         Verify: Local e2e shows new branch and commit.
 

src/git/branch.ts

@@ -0,0 +1,94 @@
+import { execFile } from 'node:child_process';
+import process from 'node:process';
+import { promisify } from 'node:util';
+
+const execFileAsync = promisify(execFile);
+
+export interface BranchCommitOptions {
+  repoPath: string;
+  track: string;
+  files: string[];
+  commitMessage: string;
+  branchPrefix?: string;
+  authorName?: string;
+  authorEmail?: string;
+}
+
+export interface BranchCommitResult {
+  branch: string;
+  commitCreated: boolean;
+  filesCommitted: string[];
+}
+
+async function runGit(
+  args: string[],
+  repoPath: string,
+): Promise<{ stdout: string; stderr: string }> {
+  const { stdout, stderr } = await execFileAsync('git', args, {
+    cwd: repoPath,
+    env: {
+      ...process.env,
+      LC_ALL: 'C',
+    },
+  });
+  return { stdout: stdout.trim(), stderr: stderr.trim() };
+}
+
+async function stageFiles(files: string[], repoPath: string): Promise<void> {
+  if (files.length === 0) {
+    return;
+  }
+  await runGit(['add', '--', ...files], repoPath);
+}
+
+async function getStagedFiles(repoPath: string): Promise<string[]> {
+  const { stdout } = await runGit(['diff', '--cached', '--name-only'], repoPath);
+  if (!stdout) {
+    return [];
+  }
+  return stdout
+    .split('\n')
+    .map((value) => value.trim())
+    .filter(Boolean);
+}
+
+export async function createBranchAndCommit(
+  options: BranchCommitOptions,
+): Promise<BranchCommitResult> {
+  const {
+    repoPath,
+    track,
+    files,
+    commitMessage,
+    branchPrefix = 'chore/bump-python-',
+    authorName,
+    authorEmail,
+  } = options;
+
+  const branch = `${branchPrefix}${track}`;
+
+  await runGit(['checkout', '-B', branch], repoPath);
+  await stageFiles(files, repoPath);
+  const stagedFiles = await getStagedFiles(repoPath);
+
+  if (stagedFiles.length === 0) {
+    return { branch, commitCreated: false, filesCommitted: [] };
+  }
+
+  const env = { ...process.env };
+  if (authorName) {
+    env.GIT_AUTHOR_NAME = authorName;
+    env.GIT_COMMITTER_NAME = authorName;
+  }
+  if (authorEmail) {
+    env.GIT_AUTHOR_EMAIL = authorEmail;
+    env.GIT_COMMITTER_EMAIL = authorEmail;
+  }
+
+  await execFileAsync('git', ['commit', '-m', commitMessage], {
+    cwd: repoPath,
+    env,
+  });
+
+  return { branch, commitCreated: true, filesCommitted: stagedFiles };
+}

src/git/index.ts

@@ -0,0 +1,2 @@
+export { createBranchAndCommit } from './branch';
+export type { BranchCommitOptions, BranchCommitResult } from './branch';

src/versioning/pre-release-guard.ts

@@ -13,7 +13,7 @@ export function enforcePreReleaseGuard(
     return { allowed: true };
   }
 
-  const parsed = semver.parse(version, { includePrerelease: true, loose: true });
+  const parsed = semver.parse(version, { loose: true });
   if (!parsed) {
     return { allowed: true };
   }

tests/git-branch.test.ts

@@ -0,0 +1,77 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import { mkdtemp, writeFile, rm } from 'node:fs/promises';
+import path from 'node:path';
+import { tmpdir } from 'node:os';
+import { execFile } from 'node:child_process';
+import { promisify } from 'node:util';
+
+import { createBranchAndCommit } from '../src/git';
+
+const execFileAsync = promisify(execFile);
+
+async function runGit(args: string[], cwd: string): Promise<string> {
+  const { stdout } = await execFileAsync('git', args, { cwd });
+  return stdout.trim();
+}
+
+describe('createBranchAndCommit', () => {
+  let repoDir: string;
+
+  beforeEach(async () => {
+    repoDir = await mkdtemp(path.join(tmpdir(), 'git-branch-'));
+    await runGit(['init'], repoDir);
+    await runGit(['config', 'user.name', 'Test User'], repoDir);
+    await runGit(['config', 'user.email', '[email protected]'], repoDir);
+
+    const filePath = path.join(repoDir, 'README.md');
+    await writeFile(filePath, 'initial\n');
+    await runGit(['add', 'README.md'], repoDir);
+    await runGit(['commit', '-m', 'Initial commit'], repoDir);
+  });
+
+  afterEach(async () => {
+    await rm(repoDir, { recursive: true, force: true });
+  });
+
+  it('creates branch and commits staged changes', async () => {
+    const filePath = path.join(repoDir, 'Dockerfile');
+    await writeFile(filePath, 'FROM python:3.11.8-slim\n');
+
+    const result = await createBranchAndCommit({
+      repoPath: repoDir,
+      track: '3.11',
+      files: ['Dockerfile'],
+      commitMessage: 'chore: bump python to 3.11.9',
+      authorName: 'Python Bot',
+      authorEmail: '[email protected]',
+    });
+
+    expect(result.branch).toBe('chore/bump-python-3.11');
+    expect(result.commitCreated).toBe(true);
+    expect(result.filesCommitted).toEqual(['Dockerfile']);
+
+    const currentBranch = await runGit(['rev-parse', '--abbrev-ref', 'HEAD'], repoDir);
+    expect(currentBranch).toBe('chore/bump-python-3.11');
+
+    const lastCommit = await runGit(['log', '-1', '--pretty=%s'], repoDir);
+    expect(lastCommit).toBe('chore: bump python to 3.11.9');
+  });
+
+  it('skips commit when no changes staged', async () => {
+    const result = await createBranchAndCommit({
+      repoPath: repoDir,
+      track: '3.12',
+      files: ['README.md'],
+      commitMessage: 'chore: noop commit',
+    });
+
+    expect(result.commitCreated).toBe(false);
+    expect(result.filesCommitted).toEqual([]);
+
+    const currentBranch = await runGit(['rev-parse', '--abbrev-ref', 'HEAD'], repoDir);
+    expect(currentBranch).toBe('chore/bump-python-3.12');
+
+    const status = await runGit(['status', '--short'], repoDir);
+    expect(status).toBe('');
+  });
+});