metro VS react-app-rewired

For details on the implementation you can see Evan's PR to metro here.

Some development tools for the web are similar (Chrome debugger, mostly) to those for React Native, but other aspects are very different (working with the metro bundler, using Flipper, AsyncStorage debugging, more). Some techniques developers will use are the same (breakpoints and console logging), but others are different (knowing when to restart the packager vs reinstall the app on device).

We’re almost done with setting up the project. The last thing in the React Native app is to add watchFolders so metro knows where the linked node_modules are. The shared modules are symlinked by yarn, and since metro doesn’t follow symlinks we need to explicitly say it where the linked node_modules are.

Unfortunately it is what it is... I use intellij instead of webstorm since they're the same thing basically. I spent a shitton of time figuring out how to link a local package i was creating for my app only to discover about this issue that is almost as old as react native itself. (luckily there's rnx-kit that solves the problem). Not to talk about the impossibility to have one goddamn IDE to write both typescript, java and c++. Currently i have to write ts/js in intellij, then i have to switch to android studio to write java/c++.

React Native packager. Override instructions here.

React Native doesn't play nicely with most monorepo tools out of the box as Metro doesn't support symlinking.

Because React Native for Web is a React website, you can use front-end tools to build and run it. For example, you can build it with Webpack or Rollup instead of Metro bundler.

Before we can run the app, we still need do one more thing: make metro bundler compatible with Yarn workspaces' hoisting.

Second, sharing code with other projects (e.g., backend code, web apps) may get complicated. Out-of-the-box, React Native's metro bundler cannot reference code outside of the project's root directory. You can configure it to do so (and we'll do it as well later on). Still, once you do it, you'll also need to ensure dependencies resolution works correctly (to avoid loading two different versions of the same library, for example); which might not be as easy as it may sound.

Further information here: https://github.com/timarney/react-app-rewired

Ejecting a React app is a bad idea because our application will lose all the React configurations and will not benefit from the CRA updates. Some solutions for ejecting our application include using packages like react-app-rewired or rewire. You can also use CRACO to eject your React application, but it needs you to install additional plugins.

When created I remove react-script package and copies build dependencies, configuration files and scripts into the app directory. It is needed to modify webpack.config file. (Another solution is to use react-app-rewired

Heads up: CRA5 bumped their webpack dependency to a version that no longer supports node polyfills in browsers. This breaks the builds of nearly all Ethereum-related projects today. A common workaround that avoids ejecting is to hook into the CRA build process. We’re using react-app-rewired but you could simply stay at CRA4 until the community comes up with a better solution.

CRA is good to get something running quick (and it uses webpack underneat!). In the past I've tweaked the webpack config using things like https://github.com/timarney/react-app-rewired when needed, but for all my "serious" projects I ended up ejecting and learning webpack! For my next project I'll try to skip CRA altogether!

// Overrides create-react-app webpack configs without ejecting // https://github.com/timarney/react-app-rewired const { addBabelPlugins, override } = require("customize-cra"); module.exports = override( ...addBabelPlugins( "babel-plugin-myPlugin" /* Add plug-in names here (separate each value by a comma) */ ) );

If Create React App supported Yarn workspaces out-of-the-box, what we've done so far would have been enough to run the app... unfortunately, it doesn't. Luckily, we can use CRACO (or other tools such as customize-cra or react-app-rewired) to customize the Webpack configuration used by Create React App to resolve packages imported from other workspaces.

<--- JS stacktrace ---> FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory 1: 00007FF69616B9CF v8::internal::CodeObjectRegistry::~CodeObjectRegistry+112159 2: 00007FF6960FCA26 v8::internal::MicrotaskQueue::GetMicrotasksScopeDepth+65430 3: 00007FF6960FD90D node::OnFatalError+301 4: 00007FF696A91BAE v8::Isolate::ReportExternalAllocationLimitReached+94 5: 00007FF696A783AD v8::SharedArrayBuffer::Externalize+78 [1]: https://github.com/timarney/react-app-rewired

Enter react-app-rewired. What this package does is it allows you to hook into the Webpack config process so you can change settings, add loaders or plugins, and so on. It's like having all the pros of ejecting (mainly, access to the webpack.config.js) without actually ejecting.

Switch to craco from react-app-rewired for better CRA v4 support (breaking change!)