TypeScript allows importing other TypeScript files with a .js extension, for compatibility with the ES6 modules loader specification. Unfortunately, Jest gets confused by this and complains that it's not able to find the JavaScript file.

This is a resolver that catches that error, and then tries to resolve it again but with a .ts extension.

Install this module into your project using npm:

npm install -D jest-ts-webcompat-resolver

Then add it to your Jest config file as the resolver:

"resolver": "jest-ts-webcompat-resolver"

This project is licensed under the MIT Licence.