Generate Tests Skill

Generate high-quality, behavior-driven test files from acceptance criteria or existing source code. This skill auto-detects the project's test framework, loads framework-specific patterns, and spawns test-writer agents to produce runnable test files that follow project conventions.

CRITICAL: Complete ALL 6 phases. The workflow is not complete until Phase 6: Report is finished. After completing each phase, immediately proceed to the next phase without waiting for user prompts.

Core Principles

1. Tests before implementation -- Generated tests should initially fail (RED state) when no implementation exists, confirming they test real behavior.
2. Behavior over implementation -- Test what the code does, not how it does it. Tests should survive refactoring.
3. Follow project conventions -- Match the project's existing test framework, file naming, directory structure, and assertion patterns.
4. Standalone operation -- This skill works independently. It does not require the SDD pipeline, tdd-cycle, or any other skill to function.

AskUserQuestion is MANDATORY

IMPORTANT: You MUST use the AskUserQuestion tool for ALL questions to the user. Never ask questions through regular text output.

• Framework selection questions -> AskUserQuestion
• Clarifying questions about scope -> AskUserQuestion
• Confirmation questions -> AskUserQuestion

Text output should only be used for presenting information, summaries, and progress updates.

Phase 1: Parse Input

Goal: Determine the operating mode and resolve input paths.

Analyze the $ARGUMENTS to determine which mode to use:

Mode Detection

Criteria-Driven Mode -- triggered when input is:

• A spec file path (e.g., specs/SPEC-feature.md)
• A task ID (e.g., 5, #5, task-5)
• A spec section reference (e.g., specs/SPEC-feature.md Section 5.1)

Code-Analysis Mode -- triggered when input is:

• A source file path (e.g., src/utils.py, src/services/auth.ts)
• A directory path (e.g., src/services/)

Ambiguous input: If the input could be either mode (e.g., a path that could be a spec or source file), check the file content. If it contains **Acceptance Criteria:** or is a markdown file in a specs/ directory, use criteria-driven mode. Otherwise, use code-analysis mode.

Path Resolution

1. Resolve relative paths against the project root
2. For task IDs: use TaskGet to retrieve the task description, then extract acceptance criteria
3. For spec section references: read the spec file and locate the referenced section
4. For directories: glob for source files (exclude test files, node_modules, pycache, .git)
5. Validate that all resolved paths exist; if not, proceed to error handling (Phase 1 error cases below)

Error Cases

Invalid spec path:

ERROR: Spec file not found: {path}

Did you mean one of these?
{List matching files from Glob search for similar names}

Usage: /generate-tests <spec-path|task-id|file-path>

Invalid task ID:

ERROR: Task #{id} not found.

Available tasks:
{List first 5 pending/in-progress tasks from TaskList}

Usage: /generate-tests <task-id>

Empty directory:

ERROR: No source files found in {path}.

The directory exists but contains no files matching supported extensions (.py, .ts, .tsx, .js, .jsx).

Phase 2: Detect Framework

Goal: Auto-detect the project's test framework using the detection chain.

Load Detection Chain

Read the framework detection reference for the full detection algorithm:

Read: ${CLAUDE_PLUGIN_ROOT}/skills/generate-tests/references/framework-templates.md

Follow the detection chain in priority order:

Step 1: Config-File Detection (High Confidence)

Check for framework configuration files:

Python:

• pyproject.toml with [tool.pytest.ini_options] or [tool.pytest] -> pytest
• setup.cfg with [tool:pytest] -> pytest
• pytest.ini exists -> pytest
• conftest.py at project root or in tests/ -> pytest

TypeScript/JavaScript:

• vitest.config.* exists -> Vitest (takes priority)
• jest.config.* exists -> Jest
• package.json with vitest in dependencies/devDependencies -> Vitest
• package.json with jest in dependencies/devDependencies -> Jest
• package.json with "jest": {} config section -> Jest

Step 2: Existing Test File Detection (Medium Confidence)

If no config files found, scan for existing test files:

• test_*.py or *_test.py -> pytest
• *.test.ts / *.spec.ts with vitest imports -> Vitest
• *.test.ts / *.spec.ts with jest imports or no explicit imports -> Jest

Step 3: Settings Fallback (Low Confidence)

If detection is still ambiguous, check .claude/agent-alchemy.local.md for:

tdd:
  framework: pytest    # or jest, vitest, auto

If tdd.framework is set to a recognized value (pytest, jest, vitest), use it. If set to auto or an unrecognized value, continue to Step 4.

Step 4: User Prompt Fallback

If all detection methods fail, prompt the user:

AskUserQuestion:
  questions:
    - header: "Test Framework"
      question: "No test framework was detected in this project. Which framework should be used for test generation?"
      options:
        - label: "pytest"
          description: "Python testing framework (recommended for Python projects)"
        - label: "Jest"
          description: "JavaScript/TypeScript testing framework"
        - label: "Vitest"
          description: "Vite-native testing framework (modern alternative to Jest)"
        - label: "Other"
          description: "A different framework (tests may need manual adjustment)"
      multiSelect: false

Detection Result

After detection, record:

• Framework: pytest | Jest | Vitest
• Test directory: Path to test root (e.g., tests/, __tests__/, src/)
• Naming pattern: File naming convention (e.g., test_*.py, *.test.ts)
• Assertion library: Default or extended (e.g., @testing-library/jest-dom)
• Existing fixtures: Notable fixtures or test utilities found
• Confidence: High | Medium | Low

Monorepo Handling

In monorepos, detect framework per-directory by walking up from the target source file to find the nearest config file. Different directories may use different frameworks.

Phase 3: Load References

Goal: Load framework-specific patterns and project conventions.

Load Test Patterns

Read the test patterns reference for framework-specific guidance:

Read: ${CLAUDE_PLUGIN_ROOT}/skills/generate-tests/references/test-patterns.md

This provides:

• Arrange-Act-Assert and Given-When-Then patterns
• Behavior-driven vs implementation-detail test guidance
• Framework-specific naming conventions
• Anti-patterns to avoid

Load Framework Templates

Read the framework templates reference for boilerplate structure:

Read: ${CLAUDE_PLUGIN_ROOT}/skills/generate-tests/references/framework-templates.md

This provides:

• Boilerplate templates for pytest, Jest, and Vitest
• Configuration reference for each framework
• Fixture and test utility patterns

Load Cross-Plugin Skills

Load language-specific patterns and project conventions for the target project:

Read: ${CLAUDE_PLUGIN_ROOT}/../core-tools/skills/language-patterns/SKILL.md
Read: ${CLAUDE_PLUGIN_ROOT}/../core-tools/skills/project-conventions/SKILL.md

Apply these skills' guidance when generating tests to ensure:

• Language idioms are followed (TypeScript strict typing, Python type hints)
• Project naming conventions are matched
• Import patterns are consistent with the codebase

Scan Existing Tests

If the project has existing test files:

1. Read 2-3 representative test files to understand the project's test style
2. Note patterns: fixture usage, test grouping, assertion style, mock patterns
3. Match these patterns in generated tests for consistency

Phase 4: Generate Tests

Goal: Produce test files by