Closed
Description
🐛 Bug Report
In the v12 of NodeJS, they changed the list of enumerable globals. Most notably process and Buffer are no longer enumerable. So this makes tests fail if global mock implementations use any of them.
To Reproduce
Steps to reproduce the behavior:
-
Upgrade to the latest node:
> npm install -g node -
Create a test file
test.jslike:
jest.mock('./a', function() {
return process;
});- Run test
npx jest ./test.js
This will fail with
babel-plugin-jest-hoist: The module factory of `jest.mock()` is not allowed to reference any out-of-scope variables.
Invalid variable access: process
Whitelisted objects: Array, ArrayBuffer, Boolean, DataView, Date, Error, EvalError, Float32Array, Float64Array, Function, Generator, GeneratorFunction, Infinity, Int16Array, Int32Array, Int8Array, InternalError, Intl, JSON, Map, Math, NaN, Number, Object, Promise, Proxy, RangeError, ReferenceError, Reflect, RegExp, Set, String, Symbol, SyntaxError, TypeError, URIError, Uint16Array, Uint32Array, Uint8Array, Uint8ClampedArray, WeakMap, WeakSet, arguments, console, expect, isNaN, jest, parseFloat, parseInt, require, undefined, global, clearInterval, clearTimeout, setInterval, setTimeout, queueMicrotask, clearImmediate, setImmediate.
Note: This is a precaution to guard against uninitialized mock variables. If it is ensured that the mock is required lazily, variable names prefixed with `mock` (case insensitive) are permitted.
Expected behavior
It is expected for jest to know about globals.
Run npx envinfo --preset jest
Paste the results here:
System:
OS: macOS Mojave 10.14.4
CPU: (4) x64 Intel(R) Core(TM) i7-6660U CPU @ 2.40GHz
Binaries:
Node: 12.1.0 - /usr/local/bin/node
Yarn: 1.15.2 - /usr/local/bin/yarn
npm: 6.9.0 - /usr/local/bin/npm
npmPackages:
jest: file:../../../node_modules/jest => 24.8.0Suggested fix
I can suggest a quick and fair IMO fix. In https://github.com/facebook/jest/blob/master/packages/babel-plugin-jest-hoist/src/index.ts instead of
Object.keys(global).forEach(name => {
WHITELISTED_IDENTIFIERS.add(name);
});do
Object.getOwnPropertyNames(global).forEach(name => {
WHITELISTED_IDENTIFIERS.add(name);
});A PR #8429 submitted.
Quick workaround
For referencing process or Buffer in mock, you can use global like
jest.mock('./a', function() {
return global.process;
});