Cannot jest.mock('react-instantsearch') since v4.90.0

[jlowcs]

🐛 Current behavior

Since v4.90.0, mocking react-instantsearch results in all the export being undefined.

🔍 Steps to reproduce

jest.mock('react-instantsearch');

import { useInstantSearch } from 'react-instantsearch';

console.log(useInstantSearch); // undefined

This works, but it's not ideal:

jest.mock('react-instantsearch', () => ({
	...jest.requireActual('react-instantsearch'),
	useInstantSearch: jest.fn(),
}));

Live reproduction

N/A

💭 Expected behavior

We should be able to mock 'react-instantsearch' without having to use weird hacks.

Package version

react-instantsearch v4.90.0

Operating system

No response

Browser

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[jlowcs]

AI Analysis (take it with a grain of salt)

Why useClearRefinements is undefined when auto-mocking react-instantsearch after v7.26.0

Summary

After bumping react-instantsearch to v7.26.0, jest.mock('react-instantsearch') (bare auto-mock) produces undefined for hooks like useClearRefinements and useInstantSearch, instead of the expected jest.fn() stubs.

Root Cause

react-instantsearch v7.26.0 switched its build toolchain from Babel to Rollup, which changed the CJS output in two ways:

1. The __esModule flag was removed

v7.24.0 (Babel):

Object.defineProperty(exports, "__esModule", { value: true });

v7.26.0 (Rollup):

'use strict';
// no __esModule

2. Hooks are re-exported from react-instantsearch-core via dynamic getters

Hooks like useClearRefinements don't live directly in react-instantsearch — they are dynamically re-exported from react-instantsearch-core at the bottom of the CJS entry point:

// react-instantsearch/dist/cjs/index.js (v7.26.0)
Object.keys(reactInstantsearchCore).forEach(function (k) {
  if (k !== 'default' && !Object.prototype.hasOwnProperty.call(exports, k))
    Object.defineProperty(exports, k, {
      enumerable: true,
      get: function () {
        return reactInstantsearchCore[k];
      },
    });
});

When jest.mock('react-instantsearch') is called without a factory, Jest loads the real module to inspect its shape and generate jest.fn() replacements. The combination of the missing __esModule flag (which changes Babel/TS import interop behavior) and the getter-based dynamic re-exports causes Jest's auto-mock to fail to capture these properties — they end up as undefined instead of jest.fn().

Without the mock, the real module is loaded and the getters resolve correctly, which is why removing the mock makes the function defined again.

Fix

Replace the bare jest.mock('react-instantsearch') with an explicit factory:

jest.mock('react-instantsearch', () => ({
  ...jest.requireActual('react-instantsearch'),
  useClearRefinements: jest.fn(),
  useInstantSearch: jest.fn(),
}));

This bypasses the auto-mock entirely and explicitly provides jest.fn() stubs for the hooks under test.

[Haroenv]

The PR isn't ready yet, but I believe #6915 should fix this, can you confirm?

[Haroenv]

You're mentioning 4.90.0, is that a typo?

[jameskirkby]

Same issue, although I believe 4.90.0 relates to the instantsearch.js version.

For react-instantsearch, 7.25.0 works fine, whereas 7.26.0 (and 7.26.1) both cause errors when running tests.

[Haroenv]

will be fixed with #6915 once that's released.