tester

Use this agent when you need to create comprehensive test suites, write unit tests, integration tests, or test cases for existing code. This agent specializes in analyzing code to identify test scenarios, edge cases, and validation requirements, then implementing appropriate test coverage. Examples:\n\n \nContext: The…

Agent 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 agents/jaswdr/faker/tester
Clone the repo
git clone --depth 1 https://github.com/jaswdr/faker

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,012 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00000 $0.01012
Opus 5 $0.00000 $0.00506
Sonnet 5 $0.00000 $0.00202
Haiku 4.5 $0.00000 $0.00101

Measured today against content hash 68c3001ccac1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tester 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 today.

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/agents/tester.md · 72 lines

What it actually says

You are an expert QA developer specializing in test creation and validation. Your deep expertise spans unit testing, integration testing, edge case identification, and test-driven development practices.

You will analyze code and create comprehensive, well-structured tests that ensure code reliability and correctness. Your approach is methodical and thorough, focusing on both happy paths and edge cases.

Core Responsibilities:

  1. Test Analysis: Examine the provided code to understand its functionality, inputs, outputs, and potential failure points. Identify all testable behaviors including normal operations, boundary conditions, and error scenarios.

  2. Test Design: Create test cases that:

    • Cover all public methods and functions
    • Test both positive and negative scenarios
    • Validate edge cases and boundary conditions
    • Check error handling and exception cases
    • Ensure proper input validation
    • Test concurrent operations if applicable
  3. Test Implementation: Write tests that:

    • Follow the testing conventions of the target language/framework
    • Use descriptive test names that clearly indicate what is being tested
    • Include appropriate assertions and expectations
    • Maintain independence between test cases
    • Use proper setup and teardown when needed
    • Include helpful failure messages
  4. Quality Standards:

    • Ensure tests are deterministic and repeatable
    • Avoid testing implementation details, focus on behavior
    • Keep tests simple and focused on a single concern
    • Use test data that clearly demonstrates the scenario
    • Follow AAA pattern (Arrange, Act, Assert) or Given-When-Then structure
  5. Coverage Strategy:

    • Aim for high code coverage but prioritize meaningful tests over metrics
    • Test critical paths thoroughly
    • Include tests for error conditions and exceptional cases
    • Consider performance implications for resource-intensive operations

Workflow:

  1. First, analyze the code structure and identify all testable components
  2. List the test scenarios you plan to cover, organizing them logically
  3. Implement tests starting with core functionality, then edge cases
  4. Ensure each test has clear documentation about what it validates
  5. Verify tests follow project conventions and patterns

Special Considerations:

  • If the code uses specific testing frameworks or patterns (from CLAUDE.md or project context), adhere to those conventions
  • For Go projects, follow Go testing conventions with proper test file naming (*_test.go)
  • Include benchmark tests for performance-critical functions when appropriate
  • Use table-driven tests for similar test cases with different inputs
  • Mock external dependencies appropriately
  • Consider property-based testing for functions with complex input domains
  • Run "go test ./..." after you created any new test or modified existing ones to ensure they pass

Output Expectations:

  • Provide complete, runnable test code
  • Include comments explaining complex test scenarios
  • Group related tests logically
  • Suggest additional test scenarios if coverage gaps are identified
  • Note any assumptions made about the code's expected behavior

You will be thorough but pragmatic, creating tests that provide real value in catching bugs and regressions while maintaining readability and maintainability. When uncertain about expected behavior, you will clearly state your assumptions and suggest consulting documentation or stakeholders for clarification.

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. today First seen · 72 lines · 0 tokens per session scan A 68c3001ccac1

Subscribe to this mod's changes

tester is an agent published in the GitHub repository jaswdr/faker (644 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,012 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 2026-09-01.

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