Testing & QA

Test Fixture Generator

Create realistic test fixtures from DB schemas, API responses, and TypeScript types. Faker-powered data generation for comprehensive testing.

Install

Get the CLI Tool

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

npx @clinetools/fixture-gen
Requires Node.js 18+
  • Generates realistic data from TypeScript interfaces and DB schemas
  • Faker-powered: names, emails, dates, addresses, UUIDs, and more
  • Consistent cross-references between related fixtures
  • Supports JSON, TypeScript, SQL INSERT, and factory patterns
  • Preference conversation on first run — locale, format, seed options
Tutorial

How to Use It

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

1

Try Online

Paste a TypeScript interface below to generate fixtures — no install needed.

↓ Jump to interactive demo
2

Use via CLI

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

npx @clinetools/fixture-gen
3

Add to Cline / Claude Code

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

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

MCP Client Configuration

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

Example: Generate from Schema

// Prompt to your AI agent:
"Generate 10 realistic user fixtures
matching our User type"

// The agent calls:
generate_fixtures({
  type_file: "src/types/user.ts",
  interface_name: "User",
  count: 10,
  format: "json"
})

// Output: 10 user objects with realistic
// names, emails, dates, consistent IDs
Live Demo

Try It Online

Paste a TypeScript interface and generate realistic test data.

Paste TypeScript Interface

We analyze field names and types to generate realistic faker data

Try a demo:

Paste a TypeScript interface and click Generate Fixtures to create test data.

Generated Fixtures (JSON)

Learn

Why Test Fixtures Matter

Good test data is the foundation of reliable tests. Bad fixtures lead to false positives and missed bugs.

Realistic Data

Tests with "test123" and "foo@bar.com" miss real-world edge cases. Faker-generated data includes unicode names, long emails, varied date formats, and realistic values that expose bugs.

Consistent Relations

When your User fixture has id "abc-123", the Order fixture should reference the same user_id. Generated fixtures maintain referential integrity across related entities.

Reproducible

Seeded generation means the same fixtures every run. No flaky tests from random data. Change the seed for different scenarios, but keep it deterministic within a test suite.

Schema-Driven

When your types change, fixture generation adapts automatically. Add a field to your interface, re-run the generator, and all fixtures include the new field with appropriate values.

Generate Test Data That Catches Bugs

Add the Fixture Generator to your agent's toolkit and never hardcode test data again.

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