en Copyright 2015 Java http://172.16.0.5:8080/history/expo/packages/@expo/metro-config/src/transform-worker/css.ts#793fa844 fix(metro-config): Escape octal characters in runtime CSS scripts. (#22054)# Why octal characters need to be escaped in strings. --------- Co-authored-by: Expo Bot <34669131+expo-bot@users.noreply.github.com> List of files: /expo/packages/@expo/metro-config/src/transform-worker/css.ts Sun, 09 Apr 2023 23:21:37 +0000 Evan Bacon <bacon@expo.io> http://172.16.0.5:8080/history/expo/packages/@expo/metro-config/src/transform-worker/css.ts#79310320 fix(metro-config): escape backticks (#22040)# Why backticks need to be escaped for CSS script injection to work. --------- Co-authored-by: Expo Bot <34669131+expo-bot@users.noreply.github.com> List of files: /expo/packages/@expo/metro-config/src/transform-worker/css.ts Sat, 08 Apr 2023 13:53:24 +0000 Evan Bacon <bacon@expo.io> http://172.16.0.5:8080/history/expo/packages/@expo/metro-config/src/transform-worker/css.ts#9b2597ba feat(metro-config, cli): CSS support for Metro web (#21941)# Why This PR moves the CSS support from Expo Router over to `expo/metro-config` behind a beta flag. This is because we need deeper integration with Expo CLI and Metro in order to emit static CSS files in production bundles. CSS is required for media queries -> rehydration. - Related: https://github.com/expo/router/pull/397 https://github.com/expo/router/pull/223 <!-- Please describe the motivation for this PR, and link to relevant GitHub issues, forums posts, or feature requests. --> # How Instead of a babel transformer, we now use a custom "transformer" which gives us the ability to add extra metadata to a Metro module on export. This means we can pass the raw and processed CSS for writing to disk. The development version of CSS still uses script injection via JavaScript, meaning static rendering cannot currently be tested in development. CSS Modules are implemented (web-only currently) using lightningcss. The export is generated to work with React Native for web. Consider the following block: ```js export default { ...StyleSheet.create({ container: { $$css: true, _: 'hashed-container-id' } }) } ``` CSS Variables are not currently hashed, enabling the user to define variables in a global CSS file and access them in CSS Modules (subject to change in order to support native). CSS variables are accessible from the default export as strings: `styles['--color'] === '--color'`. ## Docs I've chosen to document in the versioned metro doc instead of the unversioned guide, this seems like a reasonable spot given the highly experimental nature of this feature. <!-- How did you build this feature or fix this bug and why? --> # Test Plan - Unit tests for conversion. - [x] Test in/out for transformer. - [ ] Test static export. - TBD for E2E <!-- Please describe how you tested this change and how a reviewer could reproduce your test, especially if this PR does not include automated tests! If possible, please also provide terminal output and/or screenshots demonstrating your test/reproduction. --> # Checklist <!-- Please check the appropriate items below if they apply to your diff. This is required for changes to Expo modules. --> - [ ] Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md). - [ ] Conforms with the [Documentation Writing Style Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md) - [ ] This diff will work correctly for `expo prebuild` & EAS Build (eg: updated a module plugin). List of files: /expo/packages/@expo/metro-config/src/transform-worker/css.ts Thu, 06 Apr 2023 03:07:12 +0000 Evan Bacon <bacon@expo.io>