react 过渡类型

备注

• startTransition() 由 ReactStartTransition#startTransition 实现
• ReactSharedInternals() 由 ReactSharedInternals 实现

export function addTransitionType(type: string): void {
  if (enableViewTransition) {
    const transition = ReactSharedInternals.T;
    if (transition !== null) {
      const transitionTypes = transition.types;
      if (transitionTypes === null) {
        transition.types = [type];
      } else if (transitionTypes.indexOf(type) === -1) {
        transitionTypes.push(type);
      }
    } else {
      // We're in the async gap. Simulate an implicit startTransition around it.
      if (__DEV__) {
        if (ReactSharedInternals.asyncTransitions === 0) {
          if (enableGestureTransition) {
            console.error(
              'addTransitionType can only be called inside a `startTransition()` ' +
                'or `startGestureTransition()` callback. ' +
                'It must be associated with a specific Transition.',
            );
          } else {
            console.error(
              'addTransitionType can only be called inside a `startTransition()` ' +
                'callback. It must be associated with a specific Transition.',
            );
          }
        }
      }
      startTransition(addTransitionType.bind(null, type));
    }
  }
}