Testing & QA

Test Generator

Auto-generate unit tests from function signatures, JSDoc comments, and usage patterns. Supports Jest, Vitest, pytest, and Go testing.

Install

Get the CLI Tool

Generate tests locally as an MCP server, or try it online below.

npx @clinetools/test-gen
Requires Node.js 18+
  • Analyzes function signatures, types, and JSDoc to generate meaningful tests
  • Generates edge case tests: null, undefined, empty, boundary values
  • Supports Jest, Vitest, pytest, Go testing, and Mocha frameworks
  • Creates describe/it blocks with proper setup and teardown
  • Preference conversation on first run — choose framework, style, coverage targets
Tutorial

How to Use It

Three ways to generate tests — pick the one that fits your workflow.

1

Try Online

Paste a function below and get generated tests instantly — no install needed.

↓ Jump to interactive demo
2

Use via CLI

Run as a local MCP server. On first run it asks about your test preferences.

npx @clinetools/test-gen
3

Add to Cline / Claude Code

Add to your MCP settings so your agent generates tests automatically.

"test-gen": { "command": "npx", "args": ["@clinetools/test-gen"] }

MCP Client Configuration

{
  "mcpServers": {
    "test-gen": {
      "command": "npx",
      "args": ["@clinetools/test-gen"]
    }
  }
}

Example: Generate Tests for a Module

// Prompt to your AI agent:
"Generate comprehensive unit tests for
src/utils/validation.ts"

// The agent calls:
generate_tests({
  file_path: "src/utils/validation.ts",
  framework: "jest",
  include_edge_cases: true,
  coverage_target: 90
})

// Output: complete test file with describe blocks,
// happy path tests, edge cases, and error scenarios

Preference Conversation (First Run)

// On first run, the tool asks:

1. "Which test framework do you use?"
   [x] Jest
   [ ] Vitest
   [ ] Mocha + Chai
   [ ] pytest (Python)

2. "What test style do you prefer?"
   [x] describe/it with nested groups
   [ ] Flat test() functions
   [ ] BDD-style (given/when/then)

3. "How thorough should generated tests be?"
   [ ] Quick — happy path only
   [x] Standard — happy + error cases
   [ ] Exhaustive — every edge case

// Preferences saved to .clinetools/test-gen.json
// Remembered for all future runs
Live Demo

Try It Online

Paste a function and get generated unit tests instantly.

Paste Source Code

We analyze function signatures, types, and comments to generate tests

Try a demo:
Framework:

Paste source code and click Generate Tests to create unit tests.

Generated Tests

Learn

Why Test Generation Matters

Writing tests is essential but time-consuming. AI-generated tests get you to 80% coverage in seconds.

10x Faster Test Writing

Writing tests manually takes 2-3x as long as writing the code itself. Generated tests give you a solid foundation in seconds — then you refine the edge cases that matter most.

Catch Edge Cases

Humans tend to test the happy path. Generated tests systematically cover null inputs, empty arrays, boundary values, and type coercion — the cases that cause production bugs.

Refactoring Safety Net

Generated tests create a baseline that catches regressions when you refactor. Change the implementation, run the tests — if they pass, your refactor is safe.

Documentation by Example

Tests are living documentation. Generated tests show how functions are supposed to be called, what inputs they accept, and what outputs to expect — better than comments.

Generate Tests In Seconds

Add the Test Generator to your agent's toolkit and never ship untested code again.

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