NativeScript/packages/webpack5/scripts/jest.setup.ts

import './jest.mockFiles';
// we are mocking the cwd for the tests, since webpack needs absolute paths
// and we don't want them in tests
process.cwd = () => '__jest__';

jest.mock('cosmiconfig', () => ({
	cosmiconfigSync(moduleName) {
		return {
			search() {
				// no-op in tests
				return null;
			},
		};
	},
}));

jest.mock('os', () => {
	const os = jest.requireActual('os');

	return {
		...os,
		networkInterfaces() {
			return {
				in0: [
					{
						address: '127.0.0.1',
						family: 'IPv4'
					},
					{
						address: 'in0-ipv6-should-not-use',
						family: 'IPv6'
					}
				],
				in1: [
					{
						address: '192.168.0.10',
						family: 'IPv4'
					},
					{
						address: 'in1-ipv6-should-not-use',
						family: 'IPv6'
					}
				]
			}
		}
	}
})

jest.mock('path', () => {
	const path = jest.requireActual('path');
	return {
		...path,
		resolve(...args) {
			if (args[0] === '__jest__') {
				return path.join(...args.filter(Boolean));
			}

			const resolved = path.resolve(...args);
			if (resolved.includes('__jest__')) {
				const li = resolved.lastIndexOf('__jest__');
				return resolved.substr(li);
			}

			return resolved;
		},
	};
});