Step 1 — Switch from React to Preact #2
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| "private": true, | ||
| "dependencies": { | ||
| "react": "^16.3.2", | ||
| "react-dom": "^16.3.2", |
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Getting rid of react and react-dom
| "react": "^16.3.2", | ||
| "react-dom": "^16.3.2", | ||
| "preact": "^8.2.7", | ||
| "preact-compat": "^3.18.0", |
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And replace it with preact and preact-compat
| // Hack the webpack config to load Preact instead of React | ||
| module.exports = webpackConfig => | ||
| (webpackConfig.resolve.alias = Object.assign({}, webpackConfig.resolve.alias, { | ||
| react: 'preact-compat', |
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whenever webpack is loading react, it will grab preact-compat instead
| // Map React's testing classes to Preact | ||
| const newJestConfig = function() { | ||
| const config = jestConfig.apply(this, arguments); | ||
| config.moduleNameMapper = Object.assign({}, config.moduleNameMapper, { |
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whenever jest tries to load or mock any react* modules, it will get the preact* equivalents.
| }; | ||
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| // HACK ALERT! | ||
| module.constructor._cache[ |
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HACK ALERT!
Preload Node's module cache with the hacked jest config we just made.
| import './App.css'; | ||
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| // This is just a Thing | ||
| class Thing extends Component { |
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Just a Thing to show off shallow/deep rendering during testing.
| * Remove __self and __source from the list of attributes/properties. | ||
| * babel-preset-react adds these for use with the React DevTools | ||
| */ | ||
| function removeDevAttributes(vnode) { |
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babel-preset-react adds __self and __source as props to every Component.
We need this small patch to make them go away and have reliable snapshot testing.
See preactjs/preact-render-to-string#43 (comment) for more info.
sampi
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1 participant
It's time to get hacking!
The main idea here is that we alias
react*modules with theirpreact*equivalents and pull inpreact-compatto make sure the API stays the same. This is done both for Node andwebpack.For testing, it's a bit trickier, we pull in
preact-render-to-jsonand put it on theglobalscope to be available in all tests.Due to
babel-preset-react, we need to remove__selfand__sourcefrom the output JSON to be able to reliably use snapshot testing injest.File sizes:
Source Map Analyzer output:
