Files
react/packages/shared/isValidElementType.js
Andrew Clark 5031ebf6be Accept promise as element type (#13397)
* Accept promise as element type

On the initial render, the element will suspend as if a promise were
thrown from inside the body of the unresolved component. Siblings should
continue rendering and if the parent is a Placeholder, the promise
should be captured by that Placeholder.

When the promise resolves, rendering resumes. If the resolved value
has a `default` property, it is assumed to be the default export of
an ES module, and we use that as the component type. If it does not have
a `default` property, we use the resolved value itself.

The resolved value is stored as an expando on the promise/thenable.

* Use special types of work for lazy components

Because reconciliation is a hot path, this adds ClassComponentLazy,
FunctionalComponentLazy, and ForwardRefLazy as special types of work.
The other types are not supported, but wouldn't be placed into a
separate module regardless.

* Resolve defaultProps for lazy types

* Remove some calls to isContextProvider

isContextProvider checks the fiber tag, but it's typically called after
we've already refined the type of work. We should get rid of it. I
removed some of them in the previous commit, and deleted a few more
in this one. I left a few behind because the remaining ones would
require additional refactoring that feels outside the scope of this PR.

* Remove getLazyComponentTypeIfResolved

* Return baseProps instead of null

The caller compares the result to baseProps to see if anything changed.

* Avoid redundant checks by inlining getFiberTagFromObjectType

* Move tag resolution to ReactFiber module

* Pass next props to update* functions

We should do this with all types of work in the future.

* Refine component type before pushing/popping context

Removes unnecessary checks.

* Replace all occurrences of _reactResult with helper

* Move shared thenable logic to `shared` package

* Check type of wrapper object before resolving to `default` export

* Return resolved tag instead of reassigning
2018-08-16 09:21:59 -07:00

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1.1 KiB
JavaScript

/**
* Copyright (c) 2016-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
import {
REACT_ASYNC_MODE_TYPE,
REACT_CONTEXT_TYPE,
REACT_FORWARD_REF_TYPE,
REACT_FRAGMENT_TYPE,
REACT_PROFILER_TYPE,
REACT_PROVIDER_TYPE,
REACT_STRICT_MODE_TYPE,
REACT_PLACEHOLDER_TYPE,
} from 'shared/ReactSymbols';
export default function isValidElementType(type: mixed) {
return (
typeof type === 'string' ||
typeof type === 'function' ||
// Note: its typeof might be other than 'symbol' or 'number' if it's a polyfill.
type === REACT_FRAGMENT_TYPE ||
type === REACT_ASYNC_MODE_TYPE ||
type === REACT_PROFILER_TYPE ||
type === REACT_STRICT_MODE_TYPE ||
type === REACT_PLACEHOLDER_TYPE ||
(typeof type === 'object' &&
type !== null &&
(typeof type.then === 'function' ||
type.$$typeof === REACT_PROVIDER_TYPE ||
type.$$typeof === REACT_CONTEXT_TYPE ||
type.$$typeof === REACT_FORWARD_REF_TYPE))
);
}