implement-regression-tests

A command that completes tests marked with `it.skip`, which tells the test runner to leave a test unexecuted. It writes tests for the behavior the code currently has and runs them afterward.

In plain words
What is it for?
Use it to find skipped tests in a file or directory, implement their test bodies, enable them, and verify that they pass.
Why use it?
It turns unfinished regression tests into working checks that record existing behavior. This helps detect later changes that accidentally break that behavior.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/liam-hq/liam/implement-regression-tests
Clone the repo
git clone --depth 1 https://github.com/liam-hq/liam

Made for: Claude Code.

Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 243 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00012 $0.00243
Opus 5 $0.00006 $0.00121
Sonnet 5 $0.00002 $0.00049
Haiku 4.5 $0.00001 $0.00024

Measured 2d ago against content hash 385a067769ce, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implement-regression-tests 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 2d 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.

.claude/commands/implement-regression-tests.md · 42 lines

What it actually says

Implement Regression Tests Command

Implement tests marked with it.skip. Test current behavior as it exists today.

Arguments: $ARGUMENTS

Task

  1. Find it.skip tests in the specified file/directory
  2. Change it.skip to it
  3. Implement test body based on CURRENT behavior
  4. Run tests to verify they pass

Critical Rules

  • Test CURRENT behavior - Not ideal behavior
  • Tests MUST pass - They document what IS
  • Follow test principles - See @docs/test-principles.md
  • Minimal mocking - Only at external boundaries

Example

// Before (it.skip)
it.skip("returns null when user not found (current behavior)", () => {
  // TODO: Implement test
});

// After (implemented)
it("returns null when user not found (current behavior)", () => {
  const result = getUserById("non-existent-id");
  expect(result).toBeNull();
});

Remember: These are regression tests - they protect existing behavior from breaking.

Changes

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.

  1. 2d ago First seen · 42 lines · 12 tokens per session scan A 385a067769ce

Subscribe to this mod's changes

implement-regression-tests is a command published in the GitHub repository liam-hq/liam (5,100 stars, last pushed 4d ago), licensed Apache-2.0. It adds 12 tokens to every session and 243 once invoked, about $0.0001 per session on Opus 5. 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 2026-08-30.