express-locator/src/Instance.test.js

a service locator

import Instance from './Instance';

describe( 'Instance class', () => {
  it( 'should assign the passed props to this', () => {
    const props = {
      hello : 'hi',
      you   : 'lo',
    };
    const instance = new Instance( props );

    expect( instance ).toEqual( expect.objectContaining( props ) );
  } );

  it( 'should fetch dependencies from locator', () => {
    const get = jest.fn();
    const props = { locator: { get, }, };
    const result = 'test';
    const deps = [ result, ];

    new Instance( props, deps );

    expect( get ).toHaveBeenCalledWith( result );
  } );

  it( 'throws an error if called with nothing', () => {
    let err;

    try {
      new Instance();
    } catch ( e ) {
      err = e;
    }

    expect( err.message ).toBe( 'Locator must be provided to class in an object key-value pair' );
  } );
} );