Function create

packages/react-test-renderer/src/ReactTestRenderer.js:467–631

(
  element: React$Element<any>,
  options: TestRendererOptions,
)

}

function create(
  element: React$Element<any>,
  options: TestRendererOptions,
): {
  _Scheduler: typeof Scheduler,
  root: void,
  toJSON(): Array<ReactTestRendererNode> | ReactTestRendererNode | null,
  toTree(): mixed,
  update(newElement: React$Element<any>): any,
  unmount(): void,
  getInstance(): component(...props: any) | PublicInstance | null,
  unstable_flushSync: typeof flushSyncFromReconciler,
} {
  if (__DEV__) {
    if (
      enableReactTestRendererWarning === true &&
      global.IS_REACT_NATIVE_TEST_ENVIRONMENT !== true
    ) {
      console.error(
        'react-test-renderer is deprecated. See https://react.dev/warnings/react-test-renderer',
      );
    }
  }

  let createNodeMock = defaultTestOptions.createNodeMock;
  const isConcurrentOnly =
    disableLegacyMode === true &&
    global.IS_REACT_NATIVE_TEST_ENVIRONMENT !== true;
  let isConcurrent = isConcurrentOnly;
  let isStrictMode = false;
  if (typeof options === 'object' && options !== null) {
    if (typeof options.createNodeMock === 'function') {
      // $FlowFixMe[incompatible-type] found when upgrading Flow
      createNodeMock = options.createNodeMock;
    }
    if (isConcurrentOnly === false) {
      isConcurrent = options.unstable_isConcurrent;
    }
    if (options.unstable_strictMode === true) {
      isStrictMode = true;
    }
  }
  let container: Container = {
    children: ([]: Array<Instance | TextInstance>),
    createNodeMock,
    tag: 'CONTAINER',
  };
  let root: FiberRoot | null = createContainer(
    container,
    isConcurrent ? ConcurrentRoot : LegacyRoot,
    null,
    isStrictMode,
    false,
    '',
    defaultOnUncaughtError,
    defaultOnCaughtError,
    defaultOnRecoverableError,
    defaultOnDefaultTransitionIndicator,