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metaspartanmetaspartan/cybara/skills/test-driven-development/SKILL.md

test-driven-development

Skill38 starsChanged 5 months agoMITView on GitHub

Test-driven development discipline — write a failing test, implement the minimum to pass, then refactor. Use when adding a feature or fixing a bug where correctness matters.

190 other projects use a version of this.

Adopted by

Most recently taken up by

Used with

Projects with it also use chinese-code-review, chinese-commit-conventions and 10 more.

Other files people use alongside this one.

Files found in the same public projects as a version of this one, more often than they turn up anywhere else. Each project counts once, large collections count for less, and this file's own repository is left out.
  • Leodorareluctant259Skill

    chinese-code-review

    中文代码审查规范——在保持专业严谨的同时，用符合国内团队文化的方式给出有效反馈

    Also in 8 projects that use this

  • Leodorareluctant259Skill

    chinese-commit-conventions

    中文 Git 提交规范 — 适配国内团队的 commit message 规范和 changelog 自动化

    Also in 8 projects that use this

  • obraSkill

    diagnosing-superpowers

    Use when a superpowers session went wrong and your human partner wants to know why — repeated work, ignored plans, stumbles, poor results, a skill that didn't fire, "it took too long", "why is it so expensive", "what is it doing" — or wants to build a bug report for the superpowers maintainers, for the current session or a past one identified by id or path, on any harness.

    Also in 19 projects that use this

  • LLl0k0laDSkill

    using-agent-skills

    Use when starting a session or when you need to discover which skill applies to the current task. This is the meta-skill that governs how all other skills are discovered and invoked.

    Also in 39 projects that use this

  • LLl0k0laDSkill

    git-workflow-and-versioning

    Use when making any code change. Use when committing, branching, resolving conflicts, or when you need to organize work across multiple parallel streams.

    Also in 47 projects that use this

  • MrCipherSmithSkill

    constraint-driven-development

    Use when a project needs a persistent, measurable quality bar — starting a project without documented standards, 'set up constraints', or when coverage/perf/a11y thresholds get re-debated per-PR. Produces CONSTRAINTS.md with enforceable numbers, ratchets, and a guard against silent weakening. NOT for throwaway prototypes or a one-off CI setup.

    Also in 15 projects that use this

  • +3 more from Leodorareluctant259
  • +3 more from LLl0k0laD

The file

We split this skill into the rules it gives an agent

6 rules. 0 are common, 5 are distinctive, and 1 is very specific to this project.

  • 0

    Common

    Most of the 179 edited versions we read keep these.

  • 5

    Distinctive

    This author's own choices. Worth a look.

  • 1

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Write the test first. It forces precise specifications and gives a free regression net.

    line 8
  2. Distinctive:

    Red: Write ONE small test for the behavior you want.

    line 12
  3. Distinctive:

    Green: Write the minimum code to make that test pass.

    line 13
  4. Distinctive:

    Test behavior, not implementation.

    line 20
  5. Very specific:

    If a bug fix, write the test that reproduces the bug FIRST (see systematic-debugging).

    line 23
  6. Distinctive:

    Don't write tests that depend on wall-clock, random, or network unless you stub them.

    line 24

“Common” is measured: kept by at least 6 in 10 of the 179 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

Test-Driven Development (TDD)

Write the test first. It forces precise specifications and gives a free regression net.

Red → Green → Refactor

  1. Red. Write ONE small test for the behavior you want. Run it. It must FAIL (and fail for the right reason — an assertion, not a compile error in unrelated code).
  2. Green. Write the minimum code to make that test pass. No more, no less. Run it.
  3. Refactor. Clean up duplication while keeping tests green. Re-run after each change.

Repeat with the next smallest increment.

Rules of thumb

  • Test behavior, not implementation. Prefer public API; don't poke private internals.
  • One assertion concept per test. If "and" appears in the test name, consider splitting.
  • Name tests like it("returns X when Y") / should do Z when ….
  • If a bug fix, write the test that reproduces the bug FIRST (see systematic-debugging).
  • Don't write tests that depend on wall-clock, random, or network unless you stub them.

Running tests

  • Match the project's framework and command (bun test, pytest, go test, …).
  • For Bun projects: bun test (per AGENTS.md, Bun is the only JS runner).

When TDD is overkill

  • Throwaway exploration / spikes — write the test after you know the shape.
  • Pure UI tweaks with no logic — a visual check is fine.

TDD pays off most for: parsers, state machines, financial/permission logic, and anything with many edge cases.

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