Single-context Node.js environment for Jest
One of Jest's key features is context isolation so tests can't have side-effects on other tests by manipulating the global context. In theory that's a good idea but in practice the current implementation messes around with global types in a way which breaks pretty much all instanceof checks in tests against standard types like Uint8Array for example.
This small project provides a single-context Node.js environment which effectively sacrifices the context isolation feature by using a single context for all tests so instanceof checks works again as expected.
See Jest issue #2549 for details.
npm install -D jest-environment-node-single-context
Add this property to your Jest config: