Borrowing it
Nothing to install: this file belongs to 2SSK/dot-files. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/2SSK/dot-files/main/.claude/skills/tdd/SKILL.mdgit clone --depth 1 https://github.com/2SSK/dot-filesWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/2ssk/dot-files/tdd)<a href="https://agentmods.dev/skills/2ssk/dot-files/tdd"><img src="https://agentmods.dev/badge/skills/2ssk/dot-files/tdd/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/2ssk/dot-files/tdd"><img src="https://agentmods.dev/badge/skills/2ssk/dot-files/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00421 |
| Opus 5.5 | $0.00000 | $0.00168 |
| Sonnet 5.5 | $0.00000 | $0.00084 |
| Haiku 4.5 | $0.00000 | $0.00042 |
Grade A, and why
tdd scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 14d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Test-Driven Development Skill
Enforce TDD for every implementation task. This skill ensures quality throughtests first.
Workflow
Step 1 — Write Failing Test
- Identify the smallest unit of behavior
- Write test that fails because feature doesn't exist
- Use language-specific testing framework
- Keep test focused and simple
Step 2 — Write Minimal Code
- Implement only what's needed to pass test
- No optimization yet
- No additional features
- Get to green quickly
Step 3 — Refactor
- Clean up code while tests pass
- Improve structure, names, organization
- Ensure tests still pass
- No new functionality
Testing Patterns by Language
Go
func TestUnitName(t *testing.T) {
t.Run("should do thing", func(t *testing.T) {
// arrange
input := ...
expected := ...
// act
result := DoThing(input)
// assert
assert.Equal(t, expected, result)
})
}
TypeScript
describe('UnitName', () => {
it('should do thing', () => {
const input = ...;
const expected = ...;
const result = doThing(input);
expect(result).toEqual(expected);
});
});
C++
TEST_F(UnitNameTest, ShouldDoThing) {
auto input = ...;
auto expected = ...;
auto result = doThing(input);
EXPECT_EQ(expected, result);
}
Quality Gates
- All tests must pass before commit
- Coverage ≥ 80% for new code
- No flaky tests
- Fast execution (< 30s for unit tests)
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 14d ago First seen · 81 lines · 0 tokens per session scan A 9fc293feea31
tdd is a skill published in the GitHub repository 2SSK/dot-files (250 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 421 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-02.
Other skills, from other repositories
spec-driven-development
Build software via spec-driven development (github/spec-kit). Whenever the user asks for a feature larger than a one-line tweak, scaffold a spec-kit project, capture WHAT + WHY, declare tech stack, break into tasks, then iterate the implementation until tests pass.
test-driven-development
Use when implementing any feature or bugfix, before writing implementation code.
engram-testing-coverage
TDD and coverage standards for Engram. Trigger: When implementing behavior changes in any package.
conductor-implement
Execute tasks from a track's implementation plan following TDD workflow.
test-warp-ui
Guides testing Warp UI features and changes using the computer use tool. Use this skill only when computer-use testing was requested (explicit request or accepted offer) and the computeruse tool is available to the agent. Covers launching Warp and verifying UI behavior.
principle-test-behavior-not-implementation
Apply when you write, change, or keep a test. Assert what the code's users can observe, so that the test fails when that behavior breaks and keeps passing when only the internals change.