test.js

/* eslint-env mocha */

const sinon = require('sinon');
const proxyquire = require('proxyquire');
const assert = require('assert');

const { functionundertest } = require('../index');

describe('Testing Errors caused by HTTP Response', () => {
  let functionundertest;
  let somefunction;
  
  before('Set up a fake HTTP Server', () => {
    somefunction = sinon.fake.throws(new Error('Some Error')); // this is the error that
                                                               // somefunction would normally
                                                               // throw, that cannot be
                                                               // reliably reporoduced
    
    functionundertest = proxyquire('../index', {
      somemodule: {
        somefunction
      }
    });
  });
  
  it('Returns an empty object when the nested function throws an error', async () => {
    const result = await functionundertest(); // this function calls somemodule.somefunction
    assert.deepEqualStrict(result, {});
  });
  
  after('Assert that somefunction in somemodule has been called', () => {
    assert.ok(somefunction.calledOnce);
  });
});