test-generator

Generate comprehensive, idiomatic tests for any function, class, module, or API endpoint. test-generator understands your code's intent and produces tests that cover happy paths, edge cases, error conditions, and boundary values — across every major testing framework.

What It Does

test-generator performs deep code analysis to produce tests that actually matter:

• Coverage-driven generation: Analyzes branches, conditions, and return paths to maximize coverage
• Edge case discovery: Integer overflows, null/undefined inputs, empty collections, maximum length strings, concurrent access patterns
• Mock generation: Auto-generates mocks for external dependencies, HTTP clients, databases, and file system calls
• Fixture creation: Generates realistic test data and factory functions based on type signatures
• Assertion quality: Uses framework-idiomatic matchers (toBe, assertEqual, assert_eq) with meaningful failure messages
• Test naming: Descriptive test names following the "should X when Y" convention
• Framework detection: Auto-detects the testing framework in use from package.json, pyproject.toml, Cargo.toml, or go.mod

Installation

anvil skill install test-generator

Usage

Generate Tests for a File

/test-generator ./src/auth/jwt.ts

Generate Tests for a Specific Function

/test-generator ./src/utils/parser.ts --function parseUserInput

Generate Integration Tests

/test-generator ./src/routes/users.ts --type integration

Generate E2E Tests with Playwright

/test-generator ./src/pages/Login.tsx --type e2e --framework playwright

Generate Tests with Specific Coverage Target

/test-generator ./src/lib/ --coverage 90

Generate for a Python Module

/test-generator app/services/auth.py --framework pytest

Supported Frameworks

Language	Frameworks
JavaScript/TypeScript	Jest, Vitest, Mocha, Jasmine
Python	Pytest, unittest, nose2
Go	testing, testify, ginkgo
Rust	cargo test, rstest, proptest
E2E	Playwright, Cypress, Selenium

Configuration Options

Option	Description	Default
--type	unit, integration, e2e	unit
--framework	Override auto-detected framework	auto
--coverage	Target coverage percentage	80
--mocks	Mock strategy: auto, manual, none	auto
--output	Output file path	<file>.test.ts
--watch	Watch mode: re-generate on source change	false

Requirements

• Source file or directory to generate tests for
• Compatible test framework installed in the project