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Prathya JS

Contract-Driven Requirement Coverage for JavaScript & TypeScript

Prathya is an open-source tool that brings formal requirement traceability to software testing. It treats requirements as first-class, versioned artifacts, links tests to those requirements via annotations, and measures requirement coverage — a more meaningful quality signal than code coverage alone.

The Core Insight

Code coverage tells you what was touched. Requirement coverage tells you whether intent was verified.

Prathya introduces Contract-Driven Development (CDD) as a natural companion to established methodologies:

Methodology Focus Gap
TDD Write the test first, then the code Drives implementation but says nothing about whether the tests are the right tests
BDD Write behavior specifications in natural language Improves communication but doesn't enforce traceability or coverage measurement
CDD Define the contract first. Tests are written against the contract The contract is the source of truth — not the code, not the tests, not a ticket

Quick Start

1. Install

npm install -D @intrigsoft/pratya-vitest @intrigsoft/pratya-core @intrigsoft/pratya

npm install -D @intrigsoft/pratya-playwright @intrigsoft/pratya-core @intrigsoft/pratya

npm install -D @intrigsoft/pratya-jest @intrigsoft/pratya-core @intrigsoft/pratya

2. Create CONTRACT.yaml

module:
  id: AUTH
  name: Auth Service
  description: Handles user authentication

requirements:
  - id: AUTH-001
    version: 1.0.0
    status: approved
    title: User login with valid credentials
    description: >
      The system must authenticate a user given valid credentials,
      returning a signed JWT.
    acceptance_criteria:
      - Returns HTTP 200 with a JWT in the response body
    corner_cases:
      - id: AUTH-001-CC-001
        description: Invalid password — must return 401
    changelog:
      - version: 1.0.0
        date: "2026-01-01"
        note: Initial definition

3. Annotate your tests

import { test, expect } from '@intrigsoft/pratya-vitest';

test('login with valid credentials returns JWT', ({ requirement }) => {
  requirement('AUTH-001');
  // test body
});

test('login with wrong password returns 401', ({ requirement }) => {
  requirement('AUTH-001-CC-001');
  // test body
});

import { test, expect } from '@intrigsoft/pratya-playwright';

test('login with valid credentials', async ({ page, requirement }) => {
  requirement('AUTH-001');
  // test body
});

const { requirement } = require('@intrigsoft/pratya-jest');

test('login with valid credentials returns JWT', () => {
  requirement('AUTH-001');
  // test body
});

4. Configure the reporter

// vitest.config.ts
import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    reporters: [
      'default',
      ['@intrigsoft/pratya-vitest/reporter', {
        contractPath: './CONTRACT.yaml',
        outputDir: './pratya-report',
      }],
    ],
  },
});

// playwright.config.ts
import { defineConfig } from '@playwright/test';

export default defineConfig({
  reporter: [
    ['list'],
    ['@intrigsoft/pratya-playwright/reporter', {
      contractPath: './CONTRACT.yaml',
      outputDir: './pratya-report',
    }],
  ],
});

// jest.config.js
module.exports = {
  reporters: ['default', ['@intrigsoft/pratya-jest/reporter', {
    contractPath: './CONTRACT.yaml',
  }]],
  setupFilesAfterFramework: ['@intrigsoft/pratya-jest/setup'],
};

5. Run

pratya run --runner vitest --coverage

Prathya produces an HTML report at pratya-report/index.html and a JSON report at pratya-report/pratya-report.json.

What's Next