Function lazy

packages/react/src/ReactLazy.js:195–232

(
  ctor: () => Thenable<{default: T, ...}>,
)

}

export function lazy<T>(
  ctor: () => Thenable<{default: T, ...}>,
): LazyComponent<T, Payload<T>> {
  const payload: Payload<T> = {
    class="cm">// We use these fields to store the result.
    _status: Uninitialized,
    _result: ctor,
  };

  const lazyType: LazyComponent<T, Payload<T>> = {
    $$typeof: REACT_LAZY_TYPE,
    _payload: payload,
    _init: lazyInitializer,
  };

  if (__DEV__ && enableAsyncDebugInfo) {
    class="cm">// TODO: We should really track the owner here but currently ReactIOInfo
    class="cm">// can only contain ReactComponentInfo and not a Fiber. It's unusual to
    class="cm">// create a lazy inside an owner though since they should be in module scope.
    const owner = null;
    const ioInfo: ReactIOInfo = {
      name: class="st">'lazy',
      start: -1,
      end: -1,
      value: null,
      owner: owner,
      debugStack: new Error(class="st">'react-stack-top-frame'),
      class="cm">// eslint-disable-next-line react-internal/no-production-logging
      debugTask: console.createTask ? console.createTask(class="st">'lazy()') : null,
    };
    payload._ioInfo = ioInfo;
    class="cm">// Add debug info to the lazy, but this doesn't have an await stack yet.
    class="cm">// That will be inferred by later usage.
    lazyType._debugInfo = [{awaited: ioInfo}];
  }

  return lazyType;
}