Support Lerna and/or Yarn Workspaces

[robertvansteen]

Are there any plans to support Lerna? By default Lerna uses the packages directory to store the packages. Right now the content of that folder is not transpiled so it's not possible to use ES6 code in there. It would be nice to have the possibility to use Lerna to create a monorepo application with create-react-app.

I've tried using the src directory with Lerna, but that conflicts with not ignoring node_modules directory inside the src directory, so it gives a ton of lint errors when you do so.

[rgbkrk]

I'm using a create-react-app created app within a lerna monorepo and am quite pleased with it. Steps:

~/someRepo/packages$ create-react-app app
~/someRepo/packages$ cd ..
~/someRepo$ lerna bootstrap
~/someRepo$ cd packages/app
~/someRepo/packages/app$ npm run start

🎉

You can require your other packages by name within the create-react-app after adding them to app's package.json and running lerna bootstrap.

[gaearon]

This is pretty nice. Does Babel transpilation still work in this case though?

[rgbkrk]

The individual packages under packages/ need to do a transpilation step. They'll be linked via lerna but the main entrypoints still need to be ES5.

[rgbkrk]

I would prefer to not have to transpile all our packages when used in an overall app and yet I know that when we publish to npm we need them to be ES5-consumable.

[jedrichards]

For me the holy grail of Lerna support with CRA would look something like,

/web-clients
├── package.json
└── packages
    ├── api
    │   └── package.json
    ├── components
    │   └── package.json
    ├── cra-app-1
    │   └── package.json
    ├── cra-app-2
    │   └── package.json
    └── something-else
        └── package.json

The idea here is that we have a monorepo for web clients that can contain multiple CRA-based apps as peers that have access to a few shared other packages (e.g. a lib of shared presentational components, maybe a lib with some api calling utils, anything else). The CRA apps should be able to require code from the other packages and Babel should know to transpile such code coming from within the monorepo automatically.

Is this possible with Lerna and CRA at the moment? Any related issues or info I can look at?

[rgbkrk]

While I'm no longer using create-react-app (using next.js), this is how we do it in nteract for various components and the notebook-preview-demo (the next.js app): https://github.com/nteract/nteract/tree/master/packages

[tbillington]

Yarn added workspaces in 1.0 recently, don't know how it impacts this but thought it might be worth mentioning.

[ashtonsix]

@gaearon I've got babel transpilation working alongside Lerna in a private fork of CRA.

Add something like this to the end of /config/paths:

module.exports.lernaRoot = path
  .resolve(module.exports.appPath, '../')
  .endsWith('packages')
  ? path.resolve(module.exports.appPath, '../../')
  : module.exports.appPath

module.exports.appLernaModules = []
module.exports.allLernaModules = fs.readdirSync(
  path.join(module.exports.lernaRoot, 'packages')
)

fs.readdirSync(module.exports.appNodeModules).forEach(folderName => {
  if (folderName === 'react-scripts') return
  const fullName = path.join(module.exports.appNodeModules, folderName)
  if (fs.lstatSync(fullName).isSymbolicLink()) {
    module.exports.appLernaModules.push(fs.realpathSync(fullName))
  }
})

Webpack configs:

// before
{
  include: paths.appSrc
}
// after
{
  include: paths.appLernaModules.concat(paths.appSrc)
}

Jest config:

// before
transformIgnorePatterns: ['[/\\\\]node_modules[/\\\\].+\\.(js|jsx|mjs)$'],

// after
transformIgnorePatterns: [
  // prettier-ignore
  '[/\\\\]node_modules[/\\\\](?!' + paths.allLernaModules.join('|') + ').*\\.(js|jsx|mjs)$'
]

Don't have the time to make a PR & add tests, comments, etc. but should be easy for someone else to do

[shendepu]

Great!! @ashtonsix . I also have the lerna set up with CRA based on your code.

My folder structure is

lerna
  -- packages
      -- local package 1 (not published to npm registry)
      -- local package 2
      -- local package 3 
      -- local package ... 
      -- real app (created with CRA)
  -- lerna.json

For anyone else, the key for webpack in CRA app to transpile jsx is add lerna packages absolute path in include of babel-loader

BTW: I have it done without forking CRA, but used a mechanism to extend CRA webpack config, you may find more detail steps in #1328 (comment)

[bradfordlemley]

I've created an example monorepo and PR 3741 that adds support for it.

monorepo
  |--packages.json: workspaces: ["apps/*", "comps/*", "cra-comps/*"] <-- (yarn workspace)
  |--lerna.json: packages: ["apps/*", "comps/*", "cra-comps/*"] <-- (lerna w/o yarn workspace)
  |--apps
    |--cra-app1 <-- basic cra-app, doesn't use any monorepo comps
    |--cra-app2 <-- basic cra-app, doesn't use any monorepo comps
    |--cra-app3 <-- uses some monorepo comps
      |--package.json: dependencies: ["comp1": <vsn>, "comp2": <vsn>]
  |--comps
    |--comp3 <-- not a cra component?
      |--package.json: main: build/index.js
      |--build/index.js  <-- don't transpile?
      |--index.js
      |--index.test.js <-- don't test?
  |--cra-comps
    |--comp1 <-- standard-ish cra component with JSX
      |--package.json: main: comp1.js
      |--comp1.js
      |--comp1.test.js
    |--comp2 <-- cra component with dependency on other cra-comp in monorepo
      |--package.json: dependencies: ["comp1"]
      |--comp2.js: import comp1 from 'comp1'
      |--comp2.test.js

I assume that it is agreed that cra-comps should be transpiled just like app src (including JSX) since that seems to be the request from above comments, but some further questions about desired functionality:

1. Which (if any) tests from cra-comps should run when running app tests? (only comps that the app specifies as dependencies?)
2. Should files from cra-comps be linted when building app?
3. Should a directory structure be enforced for cra-comps? (e.g. files need to be under /src)
4. How to flag components that should not be treated as cra-comps? (or should cra-comps be by convention, e.g. well-known directory in monorepo?)

Is this the correct place to try to get the answers for those questions?

[iamchathu]

I'm also getting error

../shared/lib/icons/coffee.d.ts 2:0
Module parse failed: The keyword 'interface' is reserved (2:0)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
| import React, { CSSProperties } from 'react';
> interface Props {
|     width: CSSProperties['width'];
|     height: CSSProperties['height'];

This is shared typescript package(shared) which pointed to build folder(lib) with definitions files and the warning comes for definition files. Seems skipLibCheck is ignored due to symlink nature of Lerna and yarn Workspace.

I have same kind of setup for another up and it doesn't gives errors but for this it gives errors.

[cwellsx]

My first attempt to integrate CRA with lerna was based on https://juliangaramendy.dev/monorepo-demo/

That was pretty successful and orthodox: components are built separately (before the CRA app), and then are then available as dependencies of the CRA app like any other dependency in node_modules would be. Unfortunately I found a problem with it, which was that when when I debugged the CRA app, the debugger couldn't set breakpoints in nor properly step into the TypeScript in component packages. That might (I'm not sure) be because WebPack is transpiling the node_modules which makes their source maps out of date.

So I looked for another way to do this and found it here:

• https://github.com/minheq/monorepo-cra-source-map

The steps are:

• Define module fields in package.json to point to the uncompiled *.ts files

  See also What is the “module” package.json field for?

• Override this line in webpack.config.js ...

  include: paths.appSrc,
  

  ... to make it (instead of one path) an array of all the paths (all the components) which webpack should be willing to transpile.

The are various ways to implement this change to webpack.config.js (many of which are suggested in comments earlier in this thread):

• Using craco

  Support Lerna and/or Yarn Workspaces #1333 (comment)

• Using customize-cra:

  Support Lerna and/or Yarn Workspaces #1333 (comment)

• Using react-app-rewired:

  https://github.com/viewstools/yarn-workspaces-cra-crna
  https://github.com/viewstools/yarn-workspaces-cra-crna/blob/master/react-app-rewire-yarn-workspaces/index.js

• Forking the whole create-react-app repository:

  https://github.com/bradfordlemley/create-react-app

Anyway I did it using react-app-rewired as described in
https://github.com/minheq/monorepo-cra-source-map

I needed to do something else (one more thing) as well: because the TypeScript source in the component packages are in src subdirectories, I had to change the import statements in the app to import from client\src instead of from client. Ideally I should have been able to, instead, fix this with baseUrl and paths in the tsconfig.json -- however these are not supported by CRA.

Given this new method (i.e. editing webpack.config.js) it's sufficient to run yarn build in the ui-react project -- its build will now also build all its dependencies. It's no longer necessary to build or pre-build the dependencies explicitly.

My example of making this change is at cwellsx/view@8d046d9

[JeremyGrieshop]

My first attempt to integrate CRA with lerna was based on https://juliangaramendy.dev/monorepo-demo/

That was pretty successful and orthodox: components are built separately (before the CRA app), and then are then available as dependencies of the CRA app like any other dependency in node_modules would be. Unfortunately I found a problem with it, which was that when when I debugged the CRA app, the debugger couldn't set breakpoints in nor properly step into the TypeScript in component packages. That might (I'm not sure) be because WebPack is transpiling the node_modules which makes their source maps out of date.

There's another issue here #8071 discussing it along with a pull request, if you would like to check it out and upvote it.

[geoyws]

@alexnitta here you are https://github.com/anthanh/lerna-react-ts-transpile-modules

You can run the app and edit the import @monorepo/common/module1-2 or the implementation packages/common/module1/index.ts and the changes will be updated.

This worked well for me. Saved my tail.

[calvinwyoung]

• Define module fields in package.json to point to the uncompiled *.ts files
  See also What is the “module” package.json field for?

• Override this line in webpack.config.js ...

  include: paths.appSrc,
  

  ... to make it (instead of one path) an array of all the paths (all the components) which webpack should be willing to transpile.

@cwellsx I'm doing the same thing to import shared packages into my CRA package, and this works beautifully. But one thing I'm struggling with is getting absolute import paths working within my shared package.

I can use absolute imports in my CRA app by setting "baseUrl": "./" in tsconfig.json. This allows me to write import statements like this within the CRA package: import { Foo } from 'src/components/Foo'.

I'd also like to do this within my shared package, but updating baseUrl in tsconfig.json within the shared package obviously doesn't work since babel doesn't read that file.

Is there another way to get absolute import paths working within shared packages?

[ricklove]

Successful setup:

• All source code acts like it is part of the main project:
• hot loading works great with changes anywhere
• vscode acts like all the source code is all part of the same codebase: navigation, refactoring, etc. works as intended, (even auto imports works most of the time)

Using same setup as:

https://github.com/anthanh/lerna-react-ts-transpile-modules/tree/master/packages/webapp

• modify package.json
  • change scripts to use react-app-rewired
  • add react-app-rewired and customize-cra devDependencies
• add config-overrides.js
  • add packages paths to babel config

Also:

• Yarn workspaces v2
• tsconfig paths (note, we are using a module prefix @lib/ to make it easy to distinguish package usage)

{
    "compilerOptions": {
        "paths": {
            "@lib/utils/*": [
                "packages/utils/*"
            ],
            "@lib/utils-react/*": [
                "packages/utils-react/*"
            ],
        }
    }
}

• typescript packages: Don't use src folder in your packages, just put the source files at the root. This allows the import without the 'src' everywhere. It's not that bad really, it just means there is an extra package.json file sitting in the middle of the source files.
• Bonus: We are actually also using a git submodule with nested yarn workspaces since most teams work in their own repos with out current setup - but this allows us to share code easily, while still having our own independent repos

[farah]

@ricklove thanks. do you mind putting all that in a repo? I think it would help a lot of people.

[raphaelpc]

@ricklove thanks, i was just able to make my lerna monorepo work following those same steps!
Also, thanks to your description i also found this great tutorial from 2019 that teachs, in more detail, how to make all that:
https://medium.com/@Notif.me/extract-your-react-components-as-dependencies-in-a-lerna-cra-project-without-ejecting-cf76236ffe82

Anyway, it would be great if create-react-app could make it easier to add those customizations without requiring those external packages.

😄

[jamiehaywood]

would be fantastic to have this feature. I followed the same tutorial that @raphaelpc followed and it does the job, but it doesn't feel right to change the start script to "start": "react-app-rewired start". Would be really keen to work on this, but it would be my first contribution to a big open source project 🙈.

[Jekins]

This is my solution:

Add this to the end of /config/paths:

module.exports.appLernaModules = []
const folderLernaPackageName = '@my-monorepo' // this is the name of your packages folder in package.json. For example: name: '@my-monorepo/utils'
const lernaRoot = path.resolve(module.exports.appPath, '../../')
const lernaPackages = path.join(lernaRoot, 'packages') // this is the name of your packages folder in monorepo

const regexpFolderLernaPackage = new RegExp(`^${folderLernaPackageName}\\/`, 'g')
const lernaPackagesFromDependencies = Object.keys(
  require(resolveApp('package.json')).dependencies
)
  .filter((packageName) => packageName.startsWith(folderLernaPackageName))
  .map((packageName) => packageName.replace(regexpFolderLernaPackage, ''))

fs.readdirSync(lernaPackages).forEach((folderName) => {
  const isDependencyNeed = lernaPackagesFromDependencies.includes(folderName)

  if (isDependencyNeed) {
    module.exports.appLernaModules.push(path.join(lernaPackages, folderName))
  }
})

Replace this in /config/webpack.config.js:

// before
{
  include: paths.appSrc
}

// after
{
  include: paths.appLernaModules.concat(paths.appSrc)
}

Thanks for the idea @ashtonsix

[baerrach]

After

yarn eject

I stopped reading.

[ricklove]

That feeling you get when you have the same problem a year later and find an answer written by your past self. Thanks past @ricklove ! Note: your memory is not great.

[Bluefitdev]

Hey guys.. any update on this i'm still stuck today trying to setup my existing cra app with lerna. Anyone tried to do it with craco? I'm getting weird error:

TypeError: this.updater.enqueueCallback is not a function

[ricklove]

Hey @ricklove! I'm back form the future. Note: jest testing is still an issue...

[cmdcolin]

I asked a (currently unanswered) stackoverflow question about this same issue here and just got reminded of this thread since I'm subscribed :)

https://stackoverflow.com/questions/71729055/creating-a-basic-monorepo-setup-that-can-get-incremental-updates-to-packages

would be really interested in this. I'd like the individual packages to all get built incrementally and then refer to the dist folders instead of the src at dev time, but it seems like many people refer to the actual src directories of their monorepo packages which is a bit awkward

[captDaylight]

@ricklove I'm here for all your time traveling

[marcofugaro]

Guys, use turborepo, this issue isn't gonna be adressed

[0xdevalias]

Guys, use turborepo

Or https://nx.dev/

[alamothe]

This is possible with Yarn PNP and CRA but not out of the box, you need to set up some kind of auto-build as soon as any files change based on watchman. It's not that difficult to get it working though.