console-test-helpers

console-test-helpers

When building CLIs that output to the console, it's useful to be able to record and validate the console output for subsequent verification. Doing so requires a console replacement to record the actual console output. console-test-helpers provides this.

Installation

yarn add console-test-helpers --dev

# or

npm install console-test-helpers --save-dev

Usage

console-test-helpers replaces the real console with a fake, which stores the output in addition to acting as a proxy for all console calls. This means the console will behave the same, but will gather output for later validation. Validation can be performed using fixtures that can be asserted against.

Below is an example of its usage in qunit-console-test-helpers, this sister package to console-test-helpers.

export function setupMockConsole(hooks: NestedHooks, options: MockConsoleOptions) {
  let resetConsole: () => void;

  setupFixtures(options); // from the qunit-fixtures package

  hooks.beforeEach(function() {
    ({ resetConsole, consoleState } = mockConsole(options));
  });

  hooks.afterEach(function() {
    resetConsole();
  });
}

And below is how it's used within tests.

import { module, test } from 'qunit';
import { setupMockConsole } from 'qunit-console-test-helpers';

// ...
module('With mocked console', function(hooks) {
  setupMockConsole(hooks, { fixturePath: './tests/fixtures' });

  test('Something that mocks the console', function(assert) {
    somethingThatUsesConsole();

    assert.console().matches('fixture-name');
  });
});

Contributing

See the Contributing guide for details.

License

This project is licensed under the MIT License.