tasks.md

1. Core Git Branch Utility

• 1.1 Create src/utils/git-utils.ts with isGitRepository(cwd: string): boolean function using execFileSync('git', ['rev-parse', '--git-dir'], { cwd, stdio: 'pipe' })
• 1.2 Add createAndCheckoutBranch(cwd: string, branchName: string): void function to src/utils/git-utils.ts that runs git checkout -b <branchName> via execFileSync
• 1.3 Add getBranchNameForChange(changeName: string): string helper that returns openspec/<changeName>
• 1.4 Export all new functions from src/utils/git-utils.ts

2. New Change Command Integration

• 2.1 Add branch?: boolean to NewChangeOptions interface in src/commands/workflow/new-change.ts
• 2.2 After successful change creation, check options.branch and if truthy call git utility functions
• 2.3 Show spinner step for git branch creation (e.g., "Creating branch 'openspec/my-feature'...")
• 2.4 On git failure (not a git repo, branch exists, git not found), show warning via ora().warn() and exit with code 1

3. CLI Flag Registration

• 3.1 Add .option('--branch', 'Create and checkout a git branch named openspec/<change-name>') to the new change command in src/cli/index.ts
• 3.2 Pass branch option through to newChangeCommand call

4. Tests

• 4.1 Create test/core/commands/new-change-git-branch.test.ts with unit tests for isGitRepository, createAndCheckoutBranch, and getBranchNameForChange using mocked execFileSync
• 4.2 Test: isGitRepository returns true when git command succeeds
• 4.3 Test: isGitRepository returns false when git command throws (not a git repo or git not found)
• 4.4 Test: getBranchNameForChange('my-feature') returns 'openspec/my-feature'
• 4.5 Test: createAndCheckoutBranch calls execFileSync with correct args ['checkout', '-b', 'openspec/my-feature']
• 4.6 Test: newChangeCommand with --branch calls git utilities when change creation succeeds
• 4.7 Test: newChangeCommand with --branch exits nonzero when not in git repo (but change dir is still created)
• 4.8 Test: newChangeCommand without --branch never calls git utilities

5. Verification

• 5.1 Run pnpm build and ensure no TypeScript errors
• 5.2 Run pnpm test and ensure all tests pass
• 5.3 Manually test: openspec new change test-branch-feature --branch creates the branch and checks it out
• 5.4 Verify with git branch that openspec/test-branch-feature is the current branch
• 5.5 Clean up test branch: git checkout main && git branch -D openspec/test-branch-feature
• 5.6 Delete the test change: rm -rf openspec/changes/test-branch-feature