74 lines
2.2 KiB
JavaScript
74 lines
2.2 KiB
JavaScript
/**
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*
|
|
* @flow
|
|
* @format
|
|
*/
|
|
|
|
'use strict';
|
|
|
|
const React = require('react');
|
|
|
|
opaque type DoNotCommitUsageOfPureComponentDebug = {...};
|
|
|
|
/**
|
|
* Identifies which prop or state changes triggered a re-render of a PureComponent. Usage:
|
|
*
|
|
* Change `extends React.PureComponent` to `extends PureComponentDebug` or inject it
|
|
* everywhere by putting this line in your app setup:
|
|
*
|
|
* React.PureComponent = require('PureComponentDebug');
|
|
*
|
|
* Should only be used for local testing, and will trigger a flow failure if you try to
|
|
* commit any usages.
|
|
*/
|
|
class PureComponentDebug<
|
|
P: DoNotCommitUsageOfPureComponentDebug,
|
|
S: ?Object = void,
|
|
> extends React.Component<P, S> {
|
|
shouldComponentUpdate(nextProps: P, nextState: S): boolean {
|
|
const tag = this.constructor.name;
|
|
let ret = false;
|
|
const prevPropsKeys = Object.keys(this.props);
|
|
const nextPropsKeys = Object.keys(nextProps);
|
|
if (prevPropsKeys.length !== nextPropsKeys.length) {
|
|
ret = true;
|
|
console.warn(
|
|
'PureComponentDebug: different prop keys',
|
|
tag,
|
|
prevPropsKeys.filter(key => !nextPropsKeys.includes(key)),
|
|
nextPropsKeys.filter(key => !prevPropsKeys.includes(key)),
|
|
);
|
|
}
|
|
const prevStateKeys = Object.keys(this.state || {});
|
|
const nextStateKeys = Object.keys(nextState || {});
|
|
if (prevStateKeys.length !== nextStateKeys.length) {
|
|
ret = true;
|
|
console.warn(
|
|
'PureComponentDebug: different state keys',
|
|
tag,
|
|
prevStateKeys.filter(key => !nextStateKeys.includes(key)),
|
|
nextStateKeys.filter(key => !prevStateKeys.includes(key)),
|
|
);
|
|
}
|
|
for (const key in this.props) {
|
|
if (this.props[key] !== nextProps[key]) {
|
|
ret = true;
|
|
console.warn('PureComponentDebug: different prop values', tag, key);
|
|
}
|
|
}
|
|
for (const key in this.state) {
|
|
if (this.state[key] !== (nextState || {})[key]) {
|
|
ret = true;
|
|
console.warn('PureComponentDebug: different state values', tag, key);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
module.exports = PureComponentDebug;
|