await esmock(
  './to/module.js', // path to the target module being tested
  { ...childmocks }, // mocked definitions imported by the target module
  { ...globalmocks } // mocked definitions imported everywhere else
);

import test from 'ava';
import esmock from 'esmock';

test('should mock local files, packages and core modules', async t => {
  const main = await esmock('../src/main.js', {
    fs: { readFileSync: () => 'give it a star' },
    stringifierpackage : o => JSON.stringify(o),
    '../src/hello.js' : {
      default : () => 'world'
    },
    '../src/util.js' : {
      exportedFunction : () => 'foobar'
    }
  });

  t.is(main(), JSON.stringify({ test : 'world foobar' }));
});

test('should do global instance mocks —third parameter', async t => {
  const { getFile } = await esmock('../src/main.js', {}, {
    fs : {
      readFileSync : () => {
        return 'anywhere the instance uses fs readFileSync';
      }
    }
  });

  t.is(getFile(), 'anywhere the instance uses fs readFileSync');
});

test('should mock "await import()" using esmock.p', async t => {
  // when esmock.p is used, mock definitions are not deleted from cache
  const doAwaitImport = await esmock.p('../src/awaitImportEslint.mjs', {
    eslint : { ESLint : config => config }
  });

  // the cached definition is there when import is called
  t.is(await doAwaitImport('config'), 'config');

  esmock.purge(doAwaitImport); // clear the cache, if you wish
});