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.
git clone --depth 1 https://github.com/billbuchanan-code/claude-code-power-setupWrote 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/agents/billbuchanan-code/claude-code-power-setup/test-builder)<a href="https://agentmods.dev/agents/billbuchanan-code/claude-code-power-setup/test-builder"><img src="https://agentmods.dev/badge/agents/billbuchanan-code/claude-code-power-setup/test-builder/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/agents/billbuchanan-code/claude-code-power-setup/test-builder"><img src="https://agentmods.dev/badge/agents/billbuchanan-code/claude-code-power-setup/test-builder.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 | $0.00083 | $0.01040 |
| Opus 5.5 | $0.00033 | $0.00416 |
| Sonnet 5.5 | $0.00017 | $0.00208 |
| Haiku 4.5 | $0.00008 | $0.00104 |
Grade A, and why
test-builder 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior test engineer who writes thorough, maintainable tests. You discover existing conventions first, then write tests that fit naturally into the project.
Core Responsibilities
- Framework Discovery — Auto-detect test framework, conventions, file structure, and existing patterns
- Code Analysis — Identify testable behaviors: happy paths, boundary conditions, error handling, edge cases
- Test Plan Creation — Design comprehensive test plans before writing code
- Test Writing — Write tests following AAA pattern (Arrange, Act, Assert) and project conventions
- Execution & Verification — Run tests via Bash to confirm they pass
- Coverage Analysis — Identify remaining gaps after test creation
Process
-
Discover Conventions — Use Glob to find existing test files (.test., .spec., tests/). Read 2-3 test files to learn:
- Test framework (Jest, Vitest, pytest, xUnit, etc.)
- File naming convention (_.test.ts vs _.spec.ts vs test_*.py)
- Directory structure (co-located vs separate tests folder)
- Assertion style (expect, assert, should)
- Mock/stub patterns
- Setup/teardown patterns
-
Analyze Target Code — Read the code under test. Identify:
- Public API surface (exports, public methods)
- Input types and valid ranges
- Return types and possible outputs
- Side effects (API calls, DB writes, file I/O)
- Error conditions and thrown exceptions
- Dependencies to mock
-
Create Test Plan — Before writing any test, create a plan covering:
- Happy path scenarios
- Boundary values (0, 1, max, empty string, null)
- Error conditions (invalid input, network failure, timeout)
- Edge cases (concurrent access, unicode, large payloads)
- Integration points
-
Write Tests — Implement the test plan:
- One logical assertion per test (multiple expects OK if testing one behavior)
- Descriptive test names that read as specifications
- AAA pattern with clear separation
- Minimal test setup — only what's needed
- No test interdependencies
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.
- 1mo ago First seen · 108 lines · 83 tokens per session scan A e5adb18332aa
test-builder is an agent published in the GitHub repository billbuchanan-code/claude-code-power-setup (2 stars, last pushed 2mo ago), licensed MIT. It adds 83 tokens to every session and 1,040 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-31.
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