Jest: Manual mock discovery for Node packages is unclear (to me)

[richardscarrott]

The documentation says the mock should be placed in the same parent directory as the 'node_modules' folder, e.g.

var lodash = require('lodash'); // /__mocks__/lodash.js :)

.
├── __mocks__
│   └── lodash.js
└── node_modules
    └── lodash
        └── index.js

This works fine however I wondered how you would mock a non-main module within a package, e.g.

var lodash = require('lodash/array/compact'); // Where should the manual mock live?

I gave this a shot but I'm guessing it's not correct:

.
├── __mocks__
│   └── lodash
│       └── array
│           └── compact.js // ?
└── node_modules
    └── lodash
        └── index.js

In addition I've noticed that package mocks seem to be picked up in any '__mocks__' dir, even those which aren't adjacent to the 'node_modules' dir, e.g.

var lodash = require('lodash'); // /src/__mocks__/lodash.js :)

.
├── node_modules
│   └── lodash
│       └── index.js
└── src
    └── __mocks__
        └── lodash.js

Any insight would be much appreciated.

[bartonhammond]

Any update? I have same problem.

[tangrui]

Does anybody have some workaround of this issue?

[cpojer]

There is no workaround for this yet. Blocked on #599. I'll likely add a way for jest to properly mock node_modules (and internals) and also will make it more strict to colocate mocks.

[tangrui]

Manually call setMock will help.

I want to mock some/other/library in node_modules, then I create the path under __mocks__ folder, like:

__mocks__/
--some/
----other/
------library.js

Then call jest.setMock('some/other/library', require.requireActual('../__mocks__/some/other/library') in the test. After that when calling require('some/other/library'), jest will use the mock instead.

Please check https://github.com/zyeeda/cde.io/tree/bleeding-edge/src/config for example.

[cpojer]

I recommend using jest.mock('path/to/module', () => {…}) instead.