k6-expect

k6 library that simplifies writing tests in functional way by providing a simple and jest-like syntax for expectations.

Usage

Get started

export default function () {
    describe("Check", t => {
        const r = http.get("https://jsonplaceholder.typicode.com/users/10");
        
        // specialized and type-safe assertions 
        // ... for k6 http response 
        t.expect(response(r, x => x.ok(), x => x.validJson()))
        // ... for primitives
          .and("Id", num(r.json("id"), x => x.toEqual(10)))
          .and("Name", str(r.json("name"), x => x.not().toBeEmpty()))
          .and("Phone number", str(r.json("phone"), x => x.regex("\\d{3}-\\d{3}-\\d{4}")))
          .and("Geolocation", num(r.json("address.geo.lat"), x => x.lessThan(0)))
          .and("Company", str(r.json("company.name"), x => x.toContain("LLC")));
    });
}

Output:

     █ User check
       ✓ https://jsonplaceholder.typicode.com/users/10 is 200
       ✓ https://jsonplaceholder.typicode.com/users/10 responded with valid json
       ✓ Id is 10
       ✓ Name is not empty
       ✓ Phone number matches '\d{3}-\d{3}-\d{4}' pattern
       ✓ Geolocation is less than 0
       ✓ Company contains 'LLC'

For more information, check this examples.

Pass custom context

export class FooContext implements TestSuiteContext {
  breakOnFirstAssert: boolean;
  
  constructor() {
    this.breakOnFirstAssert = true;
  }

  sanitizeUrl(url: string): string {
    return "";
  }

  customFunction() { /* custom logic */ }
}

let fooContext = new FooContext();

export default function () {
    describe("Check", t => {
        // Test logic
        // ...
        // Access to custom logic
        t.context!.customFunction();
    }, fooContext);
}

Typescript integration

Based on k6-template-typescript.

package.json:

{
  "devDependencies": {
    "k6-expect": "X.X.X"
  }
}

webpack.config.js:

// ...
module.exports = {
  // ...
    externals: [
        function ({context, request}, c) {
            if (request.startsWith('k6') || request.startsWith('https://')) {
                return request === 'k6-expect' ? c() : c(null, 'commonjs ' + request);
            }
            return c();
        },
    ],
  // ...
}

Assertions table

| Access Function | Assertion | Supports negation | Description | |-----------------|--------------------|-------------------|-----------------------------------------------------| | that() | nil | ✓ | Check value for null or undefined | | | null | ✓ | Check value for null | | | toEqual | ✓ | Check value for equality | | bool() | toBeTruthy | ✗ | Check value for truth | | | toBeFalsy | ✗ | Check value for falsity | | collection() | toBeEmpty | ✓ | Check array for emptiness | | | length | ✓ | Check array for length | | | toContain | ✓ | Check array for occurence of an item | | num() | zero | ✓ | Check value for zero | | | between | ✓ | Check value for a hit in the interval (inclusive) | | | greaterThan | ✓ | Check that value is greater | | | greaterThanOrEqual | ✓ | Check that value is greater or equal | | | lessThan | ✓ | Check that value is less | | | lessThanOrEqual | ✓ | Check that value is less or equal | | str() | toBeEmpty | ✓ | Check value for emptiness | | | regex | ✓ | Check that value matches the pattern | | | toContain | ✓ | Check value for occurence of a string | | response() | validJson | ✓ | Check that response contains valid json | | | success | ✓ | Check that response has successful status (200-299) | | | status | ✓ | Check that response has status specified | | | ok | ✓ | Check response for 200 OK | | | accepted | ✓ | Check response for 202 ACCEPTED | | | noContent | ✓ | Check response for 204 NO CONTENT | | | badRequest | ✓ | Check response for 400 BAD REQUEST | | | unauthorized | ✓ | Check response for 401 UNAUTHORIZED | | | forbidden | ✓ | Check response for 403 FORBIDDEN | | | notFound | ✓ | Check response for 404 NOT FOUND | | | length | ✓ | Check response body length |

LICENSE

Distributed under the MIT License. See LICENSE for more information.