Restlyn is a powerful, Gherkin-based API testing framework for REST and contract testing. It converts .feature files into executable tests — no need to write step definitions or assertions manually.

• ✨ Write tests in plain Gherkin
• ⚙️ Automatically generates Mocha test code
• ✅ Supports all HTTP methods: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
• ✅ Token-based authentication, Dynamic token extraction and reuse, multi-step flows
• ✅ Configurable headers and request bodies
• ✅ Response status code assertions
• ✅ Response data assertions (contains key)
• 🔂 Built-in HTTP retry for flaky endpoints
• ✅ CSV / JSON data-driven testing
• 🏷️ Scenario tags: @skip, @only, @debug, @retry(2)
• ✅ restlyn mock server starter CLI
• ✅ Schema matching workflows
• 📊 Generates beautiful HTML & PDF test reports
• 🔧 Extensible via .restlynrc

• ✅ JSON Schema and Contract testing (via AJV)
• ✅ Schema validation per step
• ✅ Schemas loaded from external .schema.json files

• ✅ Converts Gherkin .feature files into:
  • .stepMap.json intermediate structure
  • Executable Mocha-compatible .test.js files
• ✅ Supports multi-step scenarios
• ✅ Auto-inserts fallback status assertions if missing
• ✅ Supports token interpolation in body (e.g., {{token}})
• ✅ Token assertion auto-added if extracted

• ✅ restlyn steps — generates step maps
• ✅ restlyn tests — generates test files from step maps
• ✅ restlyn verify — runs and summarizes generated tests
• ✅ restlyn schema — generate JSON schema from a live API response
• ✅ Auto-detects missing .stepMap.json files
• ✅ JSON report output for CI and warning aggregation

• ✅ Reads .restlynrc for default paths: features, stepmaps, tests, schemas
• ✅ Supports full path fallback if CLI args are not passed
• ✅ Handles:
  • Relative and absolute --file paths
  • Comma-separated test file lists
  • Glob patterns (e.g., token*.test.js)

• ✅ Dynamic variables like {{uuid}}, {{timestamp}}, {{randomEmail}}, {{randomInt}}
• ✅ Reusable step libraries (e.g., "Given I am logged in")
• ✅ Auto-generate JSON schema from live responses (with optional auto-login)
• ✅ Automatically skips regeneration unless --overwrite is passed
• ✅ Interpolates tokens into future requests
• ✅ Allows partial CLI usage with defaults
• ✅ Helpful log messages for skipped/missing tests
• ✅ CI-friendly: JSON summary + non-zero exit on warnings with --warn-as-error

Install the CLI globally (recommended if you’ll use it across projects):

npm install -g restlyn
restlyn --help

Or add it to a project (use with npx):

npm install --save-dev restlyn
npx restlyn --version

Alternatives:

• pnpm: pnpm add -D restlyn or pnpm dlx restlyn --help
• yarn: yarn add -D restlyn or yarn dlx restlyn --help

You can also clone the repo and use the CLI via node restlyn.js ...

my-api-project/
├── features/
│   └── login.feature
├── schemas/
│   └── loginResponse.schema.json
├── data/
│   └── loginData.json or .csv
├── .restlynrc
├── generated/
│   ├── stepmaps/
│   └── tests/

1. Write a .feature file in features/
2. Generate step maps:

npx restlyn steps

3. Generate test files:

npx restlyn tests

4. Run tests and generate report:

npx restlyn verify --report

This shows the full flow: Gherkin → stepMap.json → generated .test.js → run.

1. Create a simple feature file at features/user.feature:

Feature: Users

  Scenario: Get user by id
    Given base URL is "https://reqres.in/api"
    When I GET "/users/2"
    Then response status should be 200
    And response body should contain key "data"

2. Generate the step map(s):

npx restlyn steps --output generated/stepmaps --overwrite

This produces generated/stepmaps/user.stepMap.json similar to:

{
  "feature": "Users",
  "scenarios": [
    {
      "name": "Get user by id",
      "baseUrl": "https://reqres.in/api",
      "requests": [{ "method": "GET", "endpoint": "/users/2" }],
      "assertions": [
        { "type": "status", "expected": 200, "requestIndex": 0 },
        { "type": "contains", "key": "data", "requestIndex": 0 }
      ]
    }
  ]
}

3. Generate the executable test file(s):

npx restlyn tests --output generated/tests --overwrite

This produces generated/tests/user.test.js. A trimmed snippet looks like:

describe('Users', () => {
  it('Get user by id', async function () {
    const baseUrl = 'https://reqres.in/api';
    let res1;
    let config1 = { headers: { 'Content-Type': 'application/json' } };
    try {
      res1 = await retryRequest(() => get(`${baseUrl}/users/2`, config1));
    } catch (err) { res1 = err.response; }
    expect(res1.status).to.equal(200);
    expect(res1.data).to.have.property("data");
  });
});

4. Run and view a report:

npx restlyn verify --report

You’ll get a console summary plus an HTML report (and a PDF if puppeteer is installed).

Generate .stepMap.json from .feature files.

restlyn steps --file login.feature --output generated/stepmaps --overwrite

Generate test files from step maps.

restlyn tests --file login.stepMap.json --output generated/tests --overwrite

Options:

• --schemas <dir>: schema directory (default: schemas or [paths].schemas).
• --env <env>: local|mock|prod to override base URL resolution.
• --strict: fail the run if any referenced data file is missing.
• --warn-as-error: exit with non‑zero code if warnings occurred (missing schema/data).
• --quiet: suppress per-file logs; print summary + warnings file path.

Run tests and generate report.

restlyn verify              # will run and print test results on console
restlyn verify --verbose    # will run and pring details logs on console
restlyn verify --report     # will run all tests and generate .html and .pdf reports

Options:

• --json: also writes restlyn-report.json next to the HTML/PDF.
• --verbose: prints full Mocha logs for each test.
• --generated <path|file|list|glob>: run a folder, a single .test.js, a comma‑separated list, or a glob.
• --stepmaps <dir>: custom .stepMap.json directory (for scenario metadata in the report).

Outputs (default generated/report):

• restlyn-report.json — machine-readable summary
• restlyn-report.html — opens automatically
• restlyn-report.pdf — portable PDF (no collapsible sections)

Warning file (written next to tests):

• restlyn-warnings.json — aggregated missing schemas and data files

Exit codes:

• 0: success; 2: warnings present and --warn-as-error used

Starts the mock API server if mock-server.js exists in the project or the package.

restlyn mock

Generate a JSON Schema from a live API response (saved as <name>.schema.json).

restlyn schema \
  --url /users/2 \
  --method GET \
  --output userProfile \
  --env local \
  --login-url /login \
  --login-body '{"email":"eve.holt@reqres.in","password":"cityslicka"}' \
  --login-token-key token

Feature: Login API

  Scenario: Unsuccessful login
    Given base URL is "https://reqres.in/api"
    When I POST "/login" with:
      | email    | eve.holt@reqres.in |
      | password | wrong              |
    Then response status should be 401
    And response body should contain key "error"

@retry(3)
Scenario: Login with retry
  When I POST "/login" with:
    | email    | user@example.com |
    | password | secret           |
  And I extract token "token"

Then response should match schema "userProfile"

Resolved as: schemas/userProfile.schema.json

Run with:

restlyn verify --report

Generates:

• generated/report/restlyn-report.html (opens automatically)
• generated/report/restlyn-report.pdf

Includes:

• Pass/fail summary
• Scenario logs
• Tags, durations, steps

Example:

features = "features"
stepmaps = "stepmaps"
tests = "tests"
schemas = "schemas"
testData = "data"
report = "report"
timeout = 5000

localMode = true
RESTLYN_STRICT_DATA=1
RESTLYN_WARN_AS_ERROR=1

[globalHeaders]
Authorization = "Bearer your-hardcoded-or-dynamic-token"
x-api-key = "optional-api-key"

[baseUrls]
local = "http://localhost:4000"
prod = "https://api.example.com"

Notes:

• Root keys (features, tests, schemas, etc.) and [paths] are both supported; root keys remain for backward compatibility.
• Use CLI flags --strict and --warn-as-error for CI behavior. The example shows the intent, but these flags are not read as environment variables from the INI.
• Set localMode=true to prefer [baseUrls].local; use --env prod to override from the CLI.

MIT

Made with ❤️ by Amiya Pattanaik