Function __setMockFiles

packages/jest-config/src/__mocks__/fs.js:13–18

(newMockFiles)

const mockFiles = new Map();
function __setMockFiles(newMockFiles) {
  mockFiles.clear();
  for (const fileName of Object.keys(newMockFiles)) {
    mockFiles.set(fileName, newMockFiles[fileName]);
  }
}

fs.__setMockFiles = __setMockFiles;
fs.readFileSync = jest.fn(file => mockFiles.get(file));