# Create Tests > Generate pytest tests for Python code. Use when asked to write, add or scaffold tests for a function, class or module. Covers happy path, edge cases, exceptions and parametrize patterns. Use when this capability is needed. - Skill: `tomevault-io/create-tests` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/create-tests` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/create-tests/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/create-tests --- # Create Tests Generates idiomatic **pytest** test files for Python source code. ## When to Use - Writing tests for a new function or class. - Adding missing coverage to an existing module. - Scaffolding a test file from scratch. ## Procedure 1. **Read** the target source file to understand the public API and types. 2. **Check** `tests/` for existing `conftest.py`, fixtures, and naming patterns. 3. **Consult** [pytest patterns reference](./references/pytest-patterns.md) for idiomatic examples. 4. **Determine** test file path: mirror source under `tests/` - `src/pkg/module.py` → `tests/pkg/test_module.py` 5. **Write** tests covering: - Happy path (expected inputs/outputs) - Edge cases (empty, boundary, large values) - Error scenarios (`pytest.raises` with `match=`) - Multiple inputs (`pytest.mark.parametrize`) 6. **Mock** all external dependencies (HTTP, DB, file I/O) with `unittest.mock` (stdlib) or `pytest-mock` if already available. 7. **Report** what was created and any coverage gaps. ## Requirements - Type-annotate all test functions: `-> None`. - Each test has a one-line docstring. - Test names follow `test__`. - No repeated setup code — use fixtures or `parametrize`. --- > Source: [alisonpezzott/pyfabricops](https://github.com/alisonpezzott/pyfabricops) — distributed by [TomeVault](https://tomevault.io).