Install Git Pre-Commit Hooks for Copilot Agent

[josecelano]

Parent Epic: #112 - Refactor and Improve E2E Test Execution
Depends On: #120 - Configure GitHub Copilot Agent Environment (Issue 1-4)

Overview

Install Git pre-commit hooks in the Copilot agent's environment to enforce pre-commit checks deterministically. This ensures the agent cannot commit code without running linting checks, even if the agent forgets or ignores the instruction in .github/copilot-instructions.md.

Problem

Previous attempts to instruct the Copilot agent to run pre-commit checks via .github/copilot-instructions.md were not reliable. The agent sometimes:

• Forgot to run checks before committing
• Ignored the instructions
• Committed code that failed linting

Solution: Use Git hooks to enforce checks mechanistically, not instructionally.

Objectives

• Create symlink from .git/hooks/pre-commit to ./scripts/pre-commit.sh
• Install hook in Copilot setup workflow
• Verify hook works correctly (blocks bad commits)
• Document the hook installation process

Implementation Approach

Use Symlink (NOT Wrapper Script):

ln -sf ../../scripts/pre-commit.sh .git/hooks/pre-commit

Why Symlink:

• ✅ Simple - no wrapper script needed
• ✅ Always up-to-date - changes to script are immediately reflected
• ✅ Single source of truth - ./scripts/pre-commit.sh
• ✅ Easy to verify - readlink .git/hooks/pre-commit

Workflow Integration

Add to .github/workflows/copilot-setup-steps.yml:

- name: Install Git pre-commit hooks
  run: |
    # Create symlink to enforce pre-commit checks
    ln -sf ../../scripts/pre-commit.sh .git/hooks/pre-commit
    chmod +x .git/hooks/pre-commit
    
    # Verify hook is installed
    if [ -L .git/hooks/pre-commit ]; then
      echo "✅ Pre-commit hook installed successfully"
      readlink .git/hooks/pre-commit
    else
      echo "❌ Failed to install pre-commit hook"
      exit 1
    fi

Acceptance Criteria

• Pre-commit checks pass
• Hook installation added to Copilot setup workflow
• Hook successfully blocks commits that fail checks
• Hook is verified during workflow execution
• Documentation updated

Time Estimate

2-3 hours

Related Documentation

• Full specification: docs/issues/121-1-5-install-git-precommit-hooks-for-copilot.md
• Removed Integration Test Commit: e9955b0

[josecelano]

This is not working. The pre-commit checks script takes longer than Copilot waits for a bash command, and it continues; then it realises the commit was not done, tries again, and so on until we reach the whole agent timeout for a task.

I think there is a way to increase timeouts. I will try to find that in the Copilot agent docs.

In my machine pre-commit checks take ~6 minutes:

real    5m44,649s
user    10m45,778s
sys     3m18,677s