I have a library written in ES6/JSX and want to install it using npm install on a create-react-app application. How can I force babel to parse this lib from node_modules?
Something like not ignore node_modules/my-library when transpiling.
I think your library shouldn't rely on third applications dependencies,
then it won't be useful and it will only work on projects that contain Babel as a depency.
Instead, You should add Babel to your library dependencies, and create a build of your library using babel to transpile your ES6 code to ES5 code which will result in standard javascript.
Therefore, you can easily add it to any project by importing the build.
Related
I'm using Storybook to develop & test my components in isolation. I use typescript, babel, etc.
Everything works like a charm.
Now I want to compile my components as ES5 library (commonJS) and provide it to my other outer projects.
Basically storybook build command makes a whole storybook as a static website but I need the compiled components library.
The main problem here is that the storybook has some dependencies in node_modules that are ES6 modules, so babel configured to proceed them while Typescript handles my own components.
So I can't just use tsc etc. to compile my components eg components folder because typescript won't fetch and compile the dependencies from node_modules. They should be compiled to ES5, otherwise, any of my outer projects, that need to use compiled storybook components, won't be able to handle them.
Also, webpack has it's own aliases, so the whole tools zoo should be used during the deployment.
How to do it in the case of Storybook?
Should I install the webpack, etc. manually into the storybook and configure a deploy process separated of the storybook?
Can I just use the webpack of the storybook? (Because I've already configured it with Babel and Typescript).
Thanks for any help!
An alternative way here - is using babel-cli and only transpile your components as a set of files
Example of the command:
npx babel src -d lib/ --copy-files
The link to the Babel CLI: https://babeljs.io/docs/en/babel-cli
AFAIK, the configuration can include the typescript plugin
Hoes does the code get transpiled to javascript in a project created using create-react-app --scripts-version=react-scripts-ts? Does it use Babel/Webpack? I have checked package.json but no mention of any such dependency.
react-scripts* is just a wrapper for common configs.
As you can see here it uses babel-loader to convert from js/jsx to es5. Also uses ts-loader to compile from ts to js.
yes, with babel:
https://github.com/facebook/create-react-app/blob/next/packages/react-scripts/package.json
the code for compilation is in react-scripts
As a newbie I am trying to understand what the logic is under the hoods for react packages in npmjs.com repository.
I find it a little bit strange since some modules that I install works flawlessly with my application (such as react-motion), where some reject to work by giving Uncaught SyntaxError: Unexpected token import error (such as react-sortable-pane).
What I understood up to now is it has something to do with ES5. The modules that are implemented with ES6 or ES7 must be converted to ES5.
My question is, how can I understand if a package is not ES5 compatible and what can I do to convert it to ES5 during or after I used yarn add command to install the package to my node_modulesdirectory?
TL:DR Transpile your code or use:
import { SortablePane, Pane } from 'react-sortable-pane/lib/react-sortable-pane.es5';
First things first.
Two main folders Src and Lib
A common convention for javascript projects is to put all of your development code into a folder called src. This folder may contain code such as ES5 or ES6 depending on what the developer wants to work with.
The other main folder is usually called lib which contains all code from src that is transpiled (with babel for example from ES6 to ES5), converted and usually bundled (webpack minify for example) so that it can work in the browsers that that npm package supports (varies from package to package obviously). This folder only contains code that is relevant to the user using the package, i.e. all tests are not converted and bundled because their is no reason to.
Entry Point
The other important part for npm packages is the entry point for the npm package. By default NodeJS will look for an index.js file in the imported package (I think). This can be overwritten by supplying the main key in package.json.
Example in react-motion's package.json:
"main": "lib/react-motion.js"
We can see that this points to lib. But where is the lib folder on their Github??? It's not their because usually you don't want to check in a lib folder to source control because it's just transpiled for the npm package.
We can confirm this by installing react-motion and looking in node_modules/react-motion. The lib folder here exists with transpiled code that is ready to be used in any browser without babel.
But why don't all npm packages do this for me!?!??!
Most do and they should do really. I do in my packages.
The react-sortable-plane npm package is using this instead "jsnext:main": "./lib/react-sortable-pane.js" which basically means it uses ES5 syntax everywhere but with import/export and I haven't seen before because it isn't widely used.
See https://github.com/rollup/rollup/wiki/pkg.module#wait-it-just-means-import-and-export--not-other-future-javascript-features
As to why they just use import/export with ES5 features I presume it's because import/export has become standard now but I am not sure.
You will still have to transpile this package if you want older browser support or just import the .es5.js file, e.g:
import { SortablePane, Pane } from 'react-sortable-pane/lib/react-sortable-pane.es5';
Hope this helps. I know it's confusing with so many damn environments like UMD, Common, Node etc...
The solution is to account for any version of Javascript and use a transpiler to make sure that various JS versions which might be in your code and imported modules will be covered by your transpiler's configuration. Going through your modules and trying to figure out which version of Javascript they use isn't a practical exercise. Most projects have a bunch of dependencies, and all those packages have their own dependencies. So you'll end up going down a rabbit hole.
Babel is probably the most well known transpiler. With the right configuration you can have ES5, 6 or 7 code and it will transpile it all into the same JS type so it can run in all standard browser versions.
Basically the answer isn't to try and deduce what ES type your modules are, it's to create a build process that can handle the different types.
I started to build a component library that I want to publish on NPM (and reuse in other apps) by creating a React app using create-react-app. Unfortunately the create-react-app default configuration doesn't seem to support building such component libraries (see these issues). So it seems I have to eject.
Do you have some instructions what to configure after ejecting to make this a component library I can reuse in other apps (I guess some Webpack stuff)?
Re-framing my comments into an answer.
Don't eject! CRA hides a lot of stuff under the hood and ejecting throws it up. It's relatively easier to just clone your src into another project with the tooling setup done.
And it's not very difficult to setup one yourself! Here's the things you will need to do:
Basic babel and webpack configuration so your code compiles.
Make sure React and React-DOM are added as external dependencies in your package.json file and added as alias in your webpack.config.js. (A thorough discussion is here.) This is important to ensure you ship the smallest bundles only. Also, React doesn't play well with multiple copies.
Optionally, do the same for any other heavier libraries, e.g. Material-UI, Bootstrap, Lodash etc.
In webpack's configuration, decide how you want your library exports should be? You should be good with UMD.
Add main (and optionally module) entries in your package.json to let npm imports know where the components should be imported from.
Publish it.
Done!
Or, you can simply clone one of these super thin component projects and put in your components there -
https://github.com/wangzuo/react-progress-label
https://github.com/aaronshaf/react-toggle
There are more complete starter-kits as well, but IMO it's important to first know the details yourself before you abstract them away. Once you are familiar with the process, you should try leveraging the kits too as they go much beyond the basics, like test integration, react-storybook support and great npm publishing support.
UPDATES:
The purpose of CRA is to allow quick experimentation and on-boarding to React development, without going through the (somewhat complicated to a beginner) tooling setup. The intended use case of CRA, as denoted by the "App" in the name, is the whole app, not a component. Although developing anything built on language features like ES6 takes some tooling, an app typically takes more setup than a component. E.g. you also need a server component which hosts the generated code. CRA does all this and more for you.
And if you are working on an app, you will eject when you want to take control of the server side of it. It adds value in that case as you will get the basic hosting code auto-generated by CRA during eject.
To address test needs, CRA also has Jest integration, which is a test runner having React specific features like snapshot testing. Again, setting it up manually with your build pipeline is a handful and CRA once again hides all of this complexity from you, so you can simply focus on writing the tests.
This is super simple - you don't actually need webpack if you want to publish a package. Don't install it just for that if you don't want to.
If you use ES6:
You can use a simple script to create a dist folder that babel will create the files after transpiling:
"scripts": {
// other scripts
// .. might want to change "rm -rf" below if you're on a PC
"build:production": "rm -rf es && cross-env NODE_ENV=production node_modules/.bin/babel ./src -d es"
},
What this does is:
Remove the es folder, which is a build folder.
Runs babel for your files (in case they are located in src folder, change it to wherever your files reside) and create the es folder with the transpiled files.
In order to use the script above you need to install the following dependencies:
babel-cli / babel-core / babel-preset-es2015 / cross-env
Make sure you have a .babelrc file so that babel will work:
{
"presets": [
["es2015", { "modules": false }]
]
}
Now all you have to do (after running npm run build:production) is to run:
npm publish
And your library is published in npm. This is also the command you run if you want to update, just don't forget to update the version number in your package.json.
In case you have files you dont want published to npm, just have a file in your root called .npmignore (similar to .gitignore) and list everything you want excluded.
If you don't use ES6:
In this case you don't need to transpile anything, just go straight to the npm publish section above and run it on the root folder you want published.
create-react-app is meant for quick setting up and development of apps, not really for development of libraries. For one thing, create-react-app creates an index.html file when building, which is usually not needed by libraries. Libraries require a different set of configuration (much less).
I faced this problem myself and have written a React component boilerplate for writing and publishing React components: https://github.com/yangshun/react-component-starter, after referencing how popular ES6 libraries were written, such as Redux.
Pros:
Similar to create-react-app, batteries are included
It has got all the important areas covered: development, linting, testing, and distributing
Minimal configuration
Babel for transpilation to ES5 and CommonJS format
ESLint included and configured
Jest tests examples
Webpack configuration that compiles to UMD
React Storybook for quick development of the components
Support for stylesheet distribution alongside your component
Cons:
Highly opinionated in terms of choice of tooling; they follow the choices set by create-react-app.
Have to manually update each package dependencies in future (you'll face this issue if you did eject anyways)
There is minimal configuration included and setup is easy. The various webpack, Babel and ESLint configurations should be quite understandable.
Hope this will be helpful to you. Feel free to give suggestions and comments on how it can be improved.
I have written some react components.
I have a folder of ES6 files with multiple files :
components/A.js
components/Button.js
I wan't to import them like this in my futur project.
import A from 'bootstrap-styled/components/A';
I would like to create a npm package.
I need to export them in ES5 format using the SAME directory structure.
I don't wan't a single output file.
Is there any existing program that can do that ?
You need to have Babel installed in you project (I assume that it is already installed because without it you would not be able to run your ES6 in the browser. So I omit all the settings of Babel, just make sure that you have babel-cli in your project).
So all you need is:
babel components --out-dir dist
It will compile all your files from components to dist.
Than you can publish it to NPM with
"main": "dist"
in your package.json
If you are looking for automatisation of this process try this boilerplate project -
react-cdk.
It'll do the exactly you asking: compile ES6 to ES5 every time you run npm publish