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