@nestjs/schematics/dist/utils/jest-module-mapper.js

Nest - modern, fast, powerful node.js web framework (@schematics)

export function createModuleNameMapper(packageKey, packageRoot) {
    const moduleNameMapper = {};
    const packageKeyRegex = '^' + packageKey + '(|/.*)$';
    moduleNameMapper[packageKeyRegex] = packageRoot + '/$1';
    return moduleNameMapper;
}