express-locator/src/ControlledError.test.js

a service locator

import ControlledError from './ControlledError';

describe( 'ControlledError class', () => {
  const result = 'testing';

  Error.captureStackTrace = null;

  const error = new ControlledError( result );

  it( 'should have a prototype instance of Error', () => {
    expect( ControlledError.prototype instanceof Error ).toBe( true );
  } );

  describe( 'instance of ControlledError', () => {
    it( 'Should contain the message provided to the constructor', () => {
      expect( error.message ).toBe( result );
    } );

    it( 'Should contain the isControlled prop with the value true', () => {
      expect( error.isControlled ).toBe( true );
    } );

    it( 'Should call captureStackTrace if it exists', () => {
      const watch = jest.fn();

      Error.captureStackTrace = watch;

      new ControlledError();

      expect( watch ).toBeCalled();
    } );
  } );
} );