From ea26de35f287bd3a2068ac2fde273fed913da7e4 Mon Sep 17 00:00:00 2001
From: emil <emil@oblachno.fyi>
Date: Sun, 5 Jul 2026 22:43:56 +0200
Subject: [PATCH] ci: add testing-and-debugging skill for devx repo

Documents make targets for unit tests, linting, pre-push verification,
and CI failure investigation. Covers test speed limits (10s/0.5s),
coverage enforcement (100%), and common pitfalls.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
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 .devin/skills/testing-and-debugging/SKILL.md | 98 ++++++++++++++++++++
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 create mode 100644 .devin/skills/testing-and-debugging/SKILL.md

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+# testing-and-debugging
+
+Make targets for testing, debugging, and CI investigation. **Use these
+instead of raw `pytest`, `ruff`, or `actionlint` commands.**
+
+## Why Make Targets
+
+Make targets encapsulate the correct venv activation, PYTHONPATH, env
+vars, and flags. Running raw commands bypasses venv activation and
+produces false failures (missing dependencies, wrong Python version).
+
+## Unit Tests
+
+| Task | Command | Notes |
+|------|---------|-------|
+| Run all unit tests | `make test-unit` | Fast, no coverage |
+| Run with coverage | `make pytest-cov` | **Required before push** — enforces 100% |
+| Run single test | `make pytest-cov TEST=tests/test_foo.py::test_bar` | |
+| Check test speed | `make check-test-speed` | Fails if tests > 10s total or > 0.5s each |
+| Check test coverage | `make check-test-coverage` | Fails if source changed but tests didn't |
+
+## Linting
+
+| Task | Command | Notes |
+|------|---------|-------|
+| Full lint | `make lint-all` | ruff + workflow-lint + lint-dockerfiles |
+| Ruff only | `make lint-ruff` | |
+| Format check | `make lint-format` | |
+| Type check | `make typecheck` | pyright |
+| Bandit | `make lint-bandit` | Security linter |
+| Workflow lint | `make workflow-check` | actionlint + act_runner dry-run |
+| Dockerfile lint | `make lint-dockerfiles` | hadolint on all Dockerfiles |
+| Check mutable globals | `make check-mutable-globals` | Detects module-level mutable state |
+| Check dep docs | `make check-dep-docs` | Verifies pyproject.toml deps have comments |
+
+## Pre-Push Verification
+
+**Before pushing any branch:**
+
+```bash
+make pre-push
+```
+
+This runs `lint-all` + `pytest-cov`. The pre-push git hook only
+validates the Vikunja task exists — it does NOT run tests. You must
+run `make pre-push` manually.
+
+## CI Failure Investigation
+
+When investigating a CI failure:
+
+1. **Fetch logs via MCP** — use `mcp_call_tool` with gitea server,
+   `actions_run_read` method, `download_job_log` tool
+2. **Reproduce locally** — use `make pytest-cov` or `make lint-all`
+   depending on which CI job failed
+3. **Never run raw pytest** — always use the make target
+
+## Virtual Environment
+
+All commands run inside `.venv`. `make` targets handle activation
+automatically. For raw commands (rare), activate first:
+
+```bash
+source activate.sh       # bash/zsh
+source activate.fish     # fish
+source activate.zsh      # zsh
+```
+
+If `.venv` doesn't exist, run `make setup` first.
+
+## Common Pitfalls
+
+### Coverage Verification Before Push
+
+**Always run `make pytest-cov` before pushing** — CI enforces 100%
+coverage and will fail the PR if any lines are uncovered. This is the
+most common cause of CI quality job failures after code changes. The
+pre-push git hook only validates Vikunja task existence, not tests.
+
+### API Response Type Checking
+
+Never use `is True`/`is False` identity checks on API response values.
+Many APIs return boolean values as strings (`"true"`/`"false"`). Use
+the `is_truthy()`/`is_falsy()` helpers from `devx.utils.api` or compare
+against string values.
+
+### Time Mocking in Tests
+
+Always mock `time.sleep` and `time.monotonic` in unit tests using
+`@patch` decorators. Real sleep calls make tests slow and exceed test
+speed limits (10s total, 0.5s per test).
+
+### Mutable Global State
+
+The `check-mutable-globals` tool detects module-level mutable state
+(lists, dicts, sets) that can cause test pollution. Avoid module-level
+mutable defaults — use factory functions or `None` with initialization
+inside functions.
-- 
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