marko-tester

A utility that helps you test marko components within jest framework.

Requirements

Your project needs to have jest@^23 and marko@^4.13 (with marko-widgets@^7, if legacy components support is needed) installed.

Within your regular jest config, you need to specify a transform for *.marko files (Note: if your NODE_ENV is set to dev or development, you need to run jest with "cache": false option):

...
"cache": false, // Only if your NODE_ENV is either `dev` or `development`.
"transform": {
  ...
  "\\.marko$": "<rootDir>/node_modules/marko-tester/preprocessor.js"
}

You can also test projects with marko@^3.14 and marko-widgets@^6.6. In this scenario always disable jest's cache.

Configuration

You can set up tester in the "global" section of jest's config:

"globals": {
  ...
  "tester": {
    "shallow": false
  }
}

• shallow (default: true) - You can turn off shallow rendering by passing false here. That way marko won't isolate any component test.

Usage

marko-tester returns a function for you to use. Pass a relative path to a marko component file and you will receive a render method and fixtures method/object. By default this will run JEST SnapShots test for the fixtures of the component.

• render - a method that renders a component with a given input and mounts it to document.body. The mounted component instance is returned.

• fixtures - an object that contains all fixtures that are found within the __snapshots__ folder for the component. You can get content of a fixture by specifying a filename: fixtures[FixtureFileName].

As a second argument you can pass options object:

• withoutFixtures (default: false) - set this to true if you don't want automatic snapshot test execution. At this point fixtures will become executable and you will be able to run snapshot test using fixtures(). You can run specific snapshot by providing a fixture name fixtures(FixtureFileName).

• withAwait (default: false) - if your template has <await/> tag in it, you need to set this to true. At this point render will become an asynchronous function and you will need to treat it with await.

Examples

const { render, fixtures } = require('marko-tester')('../index.marko');

describe('When component is rendered without results', () => {
  let component;

  beforeEach(() => {
    component = render(fixtures['without-results']);
  });

  afterEach(() => {
    component.destroy();
  });

  ...your assertions...
});

Without fixtures:

const { render, fixtures } = require('marko-tester')('../index.marko', { withoutFixtures: true });

fixtures();

describe('When component is rendered with records', () => {
  let component;

  beforeEach(() => {
    component = render(fixtures.records);
  });

  afterEach(() => {
    component.destroy();
  });

  ...your assertions...
});

Asynchronous:

const { render, fixtures } = require('marko-tester')('../index.marko', { withAwait: true });

describe('When component is rendered without model', () => {
  let component;

  beforeEach(async () => {
    component = await render(fixtures.empty);
  });

  afterEach(() => {
    component.destroy();
  });

  ...your assertions...
});

If you just want to have snapshot test:

require('marko-tester')('../index.marko');

You can find more examples in the tests folder.

References

• marko
• jest

Thanks

• Dylan Piercey
• Abiyasa Suhardi

Licence

MIT