feat: [#121] Skip slow tests for Copilot agent with enhanced messaging

[josecelano]

Summary

This PR addresses issue #121 by implementing a solution to prevent GitHub Copilot coding agent from timing out during pre-commit checks.

Changes

1. Environment Variable Renaming

Changed: TORRUST_TD_SKIP_E2E_TESTS → TORRUST_TD_SKIP_SLOW_TESTS

Rationale:

• Action-based naming (SKIP_SLOW_TESTS) is clearer than condition-based (RUNNING_IN_AGENT_ENV)
• More descriptive of what actually happens
• Not tied to a specific environment (more flexible)
• Could be used by developers locally for faster pre-commit checks

2. Expanded Test Skipping

Now skips in fast mode:

• E2E provision and destroy tests (~44s)
• E2E configuration tests (~48s)
• Code coverage check (~1m 29s)
• Total time saved: ~3 minutes (54.8% reduction)

Still runs in fast mode:

• cargo machete (~0.08s)
• All linters (~19s)
• Unit tests - 1529 tests (~1m 16s)
• cargo doc (~44s)

3. Enhanced Pre-commit Messaging

When TORRUST_TD_SKIP_SLOW_TESTS=true, the script now displays:

⚠️  Running in fast mode (skipping slow tests)

The following tests are SKIPPED to stay within the 5-minute timeout limit:
  • E2E provision and destroy tests (~44 seconds)
  • E2E configuration tests (~48 seconds)
  • Code coverage check (~1 minute 29 seconds)

💡 These tests will run automatically in CI after PR creation.

If you want to run them manually before committing, use these commands:
  cargo run --bin e2e-provision-and-destroy-tests  # ~44s
  cargo run --bin e2e-config-tests                 # ~48s
  cargo cov-check                                  # ~1m 29s

Fast mode execution time: ~3 minutes 48 seconds

Benefits:

• Clear list of what was skipped
• Exact commands to run each test separately (all < 5 min)
• AI agents can choose to run them individually if time permits
• Informative guidance about CI safety net

4. Comprehensive Documentation

Added detailed timing tables to docs/contributing/copilot-agent/pre-commit-config.md:

Individual Task Timings:

Task	Time	% of Total	Skipped?
cargo machete	0.08s	0.04%	❌ No
All linters	18.75s	5.7%	❌ No
Unit tests	1m 16s	22.9%	❌ No
cargo doc	44s	13.4%	❌ No
E2E provision	44s	13.4%	✅ Yes
E2E config	48s	14.4%	✅ Yes
Coverage	1m 29s	26.9%	✅ Yes

Unit Tests Breakdown:

• Shows detailed breakdown of all 1529 tests across 8 test suites
• Explains why unit tests are NOT skipped despite taking 1m 16s

5. Documentation Organization

• Created docs/contributing/copilot-agent/ folder
• Moved copilot-agent-firewall.md → copilot-agent/firewall.md
• Added copilot-agent/README.md index
• Added copilot-agent/pre-commit-config.md comprehensive setup guide
• Updated all cross-references

Performance Results

• Full mode: ~5m 30s (exceeds Copilot's ~5-6 min timeout ⚠️)
• Fast mode: ~3m 48s (31% faster, ~2 min safety margin ✅)
• Unit tests: 1m 16s (kept in fast mode for quality assurance)

Testing

✅ Fast mode tested: TORRUST_TD_SKIP_SLOW_TESTS=true ./scripts/pre-commit.sh
✅ Full mode tested: ./scripts/pre-commit.sh
✅ All markdown linting passes
✅ Messaging displays correctly with timing information

Next Steps for Repository Admins

Important: Update GitHub environment variable configuration:

1. Go to Settings > Environments > copilot
2. Change variable name: TORRUST_TD_SKIP_E2E_TESTS → TORRUST_TD_SKIP_SLOW_TESTS
3. Keep value as true

CI Safety Net

Even though slow tests are skipped in pre-commit for Copilot agent, they still run:

• In GitHub Actions workflows on PR creation
• In the full CI pipeline before merging

This ensures no regressions slip through while keeping Copilot agent functional.

Related

• Closes Install Git Pre-Commit Hooks for Copilot Agent #121
• Community Discussion: https://github.com/orgs/community/discussions/178998

[josecelano]

ACK 48c3293