I am creating a shareable React component library.
The library contains many components but the end user may only need to use a few of them.
When you bundle code with Webpack (or Parcel or Rollup) it creates one single file with all the code.
For performance reasons I do not want to all that code to be downloaded by the browser unless it is actually used.
Am I right in thinking that I should not bundle the components? Should the bundling be left to the consumer of the components?
Do I leave anything else to the consumer of the components? Do I just transpile the JSX and that's it?
If the same repo contains lots of different components, what should be in main.js?
This is an extremely long answer because this question deserves an extremely long and detailed answer as the "best practice" way is more complicated than just a few-line response.
I've maintained our in-house libraries for 3.5+ years in that time I've settled on two ways I think libraries should be bundled the trade-offs depend on how big your library is and personally we compile both ways to please both subsets of consumers.
Method 1: Create an index.ts file with everything you want to be exposed exported and target rollup at this file as its input. Bundle your entire library into a single index.js file and index.css file; With external dependencies inherited from the consumer project to avoid duplication of library code.
(gist included at bottom of example config)
Pros: Easy to consume as project consumers can import everything from the root relative library path import { Foo, Bar } from "library"
Cons: This will never be tree shakable, and before people say to do this with ESM and it will be tree shakeable. NextJS doesn't support ESM at this current stage and neither do a lot of project setups that's why it's still a good idea to compile this build to just CJS. If someone imports 1 of your components they will get all the CSS and all the javascript for all your components.
Method 2: This is for advanced users: Create a new file for every export and use rollup-plugin-multi-input with the option "preserveModules: true" depending on how what CSS system you're using your also need to make sure that your CSS is NOT merged into a single file but that each CSS file requires(".css") statement is left inside the output file after rollup and that CSS file exists.
Pros: When users import { Foo } from "library/dist/foo" they will
only get the code for Foo, and the CSS for Foo, and nothing more.
Cons: This setup involves the consumer having to handle node_modules
require(".css") statements in their build configuration with NextJS
this is done with next-transpile-modules npm package.
Caveat: We use our own babel plugin you can find it here: https://www.npmjs.com/package/babel-plugin-qubic to allow people to import { Foo, Bar } from "library" and then with babel transform it to...
import { Foo } from "library/dist/export/foo"
import { Bar } from "library/dist/export/bar"
We have multiple rollup configurations where we actually use both methods; so for library consumers who don't care for tree shaking can just do "Foo from "library" and import the single CSS file, and for library consumers who do care for tree shaking and only using critical CSS they can just turn on our babel plugin.
Rollup guide for best practice:
whether you are using typescript or not ALWAYS build with "rollup-plugin-babel": "5.0.0-alpha.1"
Make sure your .babelrc looks like this.
{
"presets": [
["#babel/preset-env", {
"targets": {"chrome": "58", "ie": "11"},
"useBuiltIns": false
}],
"#babel/preset-react",
"#babel/preset-typescript"
],
"plugins": [
["#babel/plugin-transform-runtime", {
"absoluteRuntime": false,
"corejs": false,
"helpers": true,
"regenerator": true,
"useESModules": false,
"version": "^7.8.3"
}],
"#babel/plugin-proposal-class-properties",
"#babel/plugin-transform-classes",
["#babel/plugin-proposal-optional-chaining", {
"loose": true
}]
]
}
And with the babel plugin in rollup looking like this...
babel({
babelHelpers: "runtime",
extensions,
include: ["src/**/*"],
exclude: "node_modules/**",
babelrc: true
}),
And your package.json looking ATLEAST like this:
"dependencies": {
"#babel/runtime": "^7.8.3",
"react": "^16.10.2",
"react-dom": "^16.10.2",
"regenerator-runtime": "^0.13.3"
},
"peerDependencies": {
"react": "^16.12.0",
"react-dom": "^16.12.0",
}
And finally your externals in rollup looking ATLEAST like this.
const makeExternalPredicate = externalArr => {
if (externalArr.length === 0) return () => false;
return id => new RegExp(`^(${externalArr.join('|')})($|/)`).test(id);
};
//... rest of rollup config above external.
external: makeExternalPredicate(Object.keys(pkg.peerDependencies || {}).concat(Object.keys(pkg.dependencies || {}))),
// rest of rollup config below external.
Why?
This will bundle your shit to automatically to inherit
react/react-dom and your other peer/external dependencies from the
consumer project meaning they won't be duplicated in your bundle.
This will bundle to ES5
This will automatically require("..") in all the babel helper functions for objectSpread, classes, etc FROM the consumer project which will wipe another 15-25KB from your bundle size and mean that the helper functions for objectSpread won't be duplicated in your library output + the consuming projects bundled output.
Async functions will still work
externals will match anything that starts with that peer-dependency suffix i.e babel-helpers will match external for babel-helpers/helpers/object-spread
Finally here is a gist for an example single index.js file output rollup config file.
https://gist.github.com/ShanonJackson/deb65ebf5b2094b3eac6141b9c25a0e3
Where the target src/export/index.ts looks like this...
export { Button } from "../components/Button/Button";
export * from "../components/Button/Button.styles";
export { Checkbox } from "../components/Checkbox/Checkbox";
export * from "../components/Checkbox/Checkbox.styles";
export { DatePicker } from "../components/DateTimePicker/DatePicker/DatePicker";
export { TimePicker } from "../components/DateTimePicker/TimePicker/TimePicker";
export { DayPicker } from "../components/DayPicker/DayPicker";
// etc etc etc
Let me know if you experience any problems with babel, rollup, or have any questions about bundling/libraries.
When you bundle code with Webpack (or Parcel or Rollup) it creates one single file with all the code.
For performance reasons I do not want to all that code to be downloaded by the browser unless it is actually used
It's possible to have separate files generated for each component. Webpack has such ability by defining multiple entries and outputs. Let's say you have the following structure of a project
- my-cool-react-components
- src // Folder contains all source code
- index.js
- componentA.js
- componentB.js
- ...
- lib // Folder is generated when build
- index.js // Contains components all together
- componentA.js
- componentB.js
- ...
Webpack file would look something like this
const path = require('path');
module.exports = {
entry: {
index: './src/index.js',
componentA: './src/componentA.js',
componentB: './src/componentB.js',
},
output: {
filename: '[name].js',
path: path.resolve(__dirname, 'lib'),
},
};
More info on "code splitting" is here in Webpack docs
If the same repo contains lots of different components, what should be in main.js?
There is a single field in package.json file named main, it's good to put its value lib/index.js according to the project structure above. And in index.js file have all components exported. In case consumer wants to use single component it's reachable by simply doing
const componentX = require('my-cool-react-components/lib/componentX');
Am I right in thinking that I should not bundle the components? Should the bundling be left to the consumer of the components? Do I leave anything else to the consumer of the components? Do I just transpile the JSX and that's it?
Well, it's up to you. I've found that some React libraries are published in original way, others - are in bundled way. If you need some build process, then define it and export bundled version.
Hope, all your questions are answered :)
You can split your components like lodash is doing for their methods.
What you probably have is separate components that you could allow importing separately or through the main component.
Then the consumer could import the whole package
import {MyComponent} from 'my-components';
or its individual parts
import MyComponent from 'my-components/my-component';
Consumers will create their own bundles based on the components they import. That should prevent your whole bundle being downloaded.
You should take a look at Bit, I think this is a good solution to share, reuse and visualize components.
It is very easy to setup. You can install your bit library or just a component with:
npm i #bit/bit.your-library.components.buttons
Then you can import the component in your app with:
import Button3 from '#bit/bit.your-library.components.buttons';
The good part is that you don't have to worry about configuring Webpack and all that jazz. Bit even supports the versioning of your components. This example shows a title-list react component so you can take a look if this meets your requirements or not
There is a configuration in webpack to create chunk files. To start with it will create the main bundle into multiple chunks and get it loaded as when required. if your project has well structured modules, it will not load any code which is not required.
Related
I have a little problem in my application.
I use i18next and react-i18next for the translation and have already included it.
The whole translation comes from 1 file for each language and that is a mess with over 4000 rows :(
Now I want update this so that i18next would take the translation files placed in the different component-folders and their children-folders.
The folder-structure should look like this after the update:
scr
- components
-- Header
---translations (en/translation.json, de/translation.json)
-- Dashboard
--- translations (en/translation.json, de/translation.json)
--- Menu
---- translations (en/translation.json, de/translation.json)
---- ExampleComponent.tsx
---- ...
--- Cards
---- translations (en/translation.json, de/translation.json)
...
I already figured out how I can handle the automatic export via babel and babel-i18next-plugin with the "namespace"
So, my code (example Menu) would be written like this:
const { t } = useTranslation("Dashboard/Menu")
const explString = t("ExampleComponent.ExampleString","This is an example")
In babel I placed the plugin like this:
[i18next-plugin, {"outputPath": "src/components/{{ns}}/translations/{{locale}}/translation.json"}]
This runs without problems. It takes the namespace as a folder-structure and places the translation-files into the translation-folder including the correct keys.
Now, how I can tell i18next, where to find the translation-files?
I could only figure out that I can import the files (file-by-file) inside a resource.
I tried backend plugins (html-backend, async-storage-backend, local-storage-backend and filesystem) with
backend: { loadPath: "components/{{ns}}/translations/{{lng}}/translation.json" }
(The i18next.ts is placed inside src/)
and I get the warnings that the keys aren't found.
Also, you can see that I use TypeScript.
In my webpack I tried it with the ts-i18next-loader with this inside the webpack configuration file:
{
test: /\translation.json$/,
exclude: /node_modules/,
loader: 'i18next-ts-loader',
options: {
localeFilesPattern: 'src/components/{{ns}}/translations/{{lng}}/translation.json',
},
},
If I only had 5-6 translation-files for each language / namespace it would not be a problem to put it inside the resource but at the end I have more than 100 files for each language.
Would be nice if anyone had a solution to my problem. If you need any further information I can update the post.
Cheers
There's an alternative plugin to be used, suggested in the official documentation: https://www.i18next.com/how-to/add-or-load-translations#lazy-load-in-memory-translations
i18next-resources-to-backend helps to transform resources to an i18next backend. This means, you can also lazy load translations, for example when using webpack:
import i18next from 'i18next';
import resourcesToBackend from 'i18next-resources-to-backend';
i18next
.use(resourcesToBackend((language, namespace, callback) => {
import(`./locales/${language}/${namespace}.json`)
.then((resources) => {
callback(null, resources)
})
.catch((error) => {
callback(error, null)
})
}))
.init({ /* other options */ })
Found the solution.
After i included the "webpack backend for i18next" it solved the problem and the translation gets the correct file.
i18next webpack backend by SimeonC
I've never published an NPM package before. All these details to generate a package seem way too complicated to my level. The only tool, that was beginner friendly, that I could find is create-react-library which recommended to switch to tsup instead.
I'm asking here to know if there's a batteries-included, most-cases-met, setup for tsup or any other tool of your recommendation for this kind of project (and I think this is a common scenario):
A React Project
Typed with Typescript
Tested with Jest
No dependencies
Exports React components
Should be public on NPM
If you want most-cases-met, batteries-included way to make a library like that then take a look at dts-cli. It will work but it will definitely be slower than tsup. I myself am in the process of switching a library with about 60 react components from dts-cli to tsup because the build time started taking too long (about a minute) on a MacBook Air M1.
Here is an example setup.
First you need to bundle each component separately. You can use a glob as an entry point in Tsup.
Keep in mind that options that works for Esbuild works for Tsup most of the time.
// tsup.config.ts
defineConfig([
{
clean: true,
sourcemap: true,
tsconfig: path.resolve(__dirname, "./tsconfig.build.json"),
entry: ["./components/core/!(index).ts?(x)"],
format: ["esm"],
outDir: "dist/",
esbuildOptions(options, context) {
// the directory structure will be the same as the source
options.outbase = "./";
},
},
Then you'll want to have a index.ts, for convenience, that expose named exports. This index is sometimes referred as a "barrel" file.
// index.ts
// the actual file is "Button.tsx" but we still want a ".js" here
export { Button } from "./components/core/Button.js";
Notice the .js extension. ESM expects explicit extensions so it's needed in the final build.
Adding the .js doesn't seem to bother TypeScript, which stills correctly recognize the type of "Button" from Button.tsx. At this point I am not sure why it works, but it does.
Transpile this index, without bundling.
// tsup.config.ts
{
clean: true,
sourcemap: true,
tsconfig: path.resolve(__dirname, "./tsconfig.build.json"),
entry: ["index.ts", "./components/core/index.ts"],
bundle: false,
format: ["esm"],
outDir: "dist",
esbuildOptions(options, context) {
options.outbase = "./";
},
},
])
Finally define your package.json as usual:
"sideEffects": false,
"type": "module",
"exports": {
".": "./dist/index.js"
},
sideEffects is a non-standard property targeting application bundlers like Webpack and Rollup.
Setting it to false tells them that the package is safe for tree-shaking.
Now import { Button } from "my-package" should work as you expect, and tree-shaking and dynamic loading at app-level become possible because "Button" is bundled as its own ES module Button.js, and the package is marked as being side-effect free.
This is confirmed by my Webpack Bundle Analyzer in a Next app:
Before (a single bundled index.js):
After (separate files means I can select more precisely my imports):
Final config available here (might be improved in the future)
I'm trying to understand how to customize the Angular CLI build process to be able to have React components properly built when they import scss files.
I'm currently able to build an Angular project where some React components are used. There's a lot of material out there that explains how to achieve it (it's pretty simple actually).
I still haven't found an article that points out how to have scss file imports properly resolved in .tsx files though.
For example, if I have this simple React component:
import * as styles from "./styles.scss";
const ReactComponentWithBrokenStyles = () => (
<div className={styles.root}>This div won't have a class</div>
);
export default ReactComponentWithBrokenStyles;
how can I edit the Angular CLI build process to properly add the loaders that would transform the .scss file?
I've found some resources pointing me to using a custom builder instead of the standard builder, which would allow me to provide an extra webpack config file. What I don't understand is how to write the loaders in that file to solve my problem.
The default Angular CLI webpack config already has a loader for .scss files, which need to be transformed and referenced by Angular components, and I don't want to override that... so how can I add a loader just for .scss files that are imported in .tsx files? Is there a way to tell webpack to match files based on siblings in addition to the usual regex?
I guess this is exquisitely a webpack question after all.
Note: using Angular CLI v7 and webpack 4.
The real problem was: I need to distinguish Angular .scss files from React .scss files.
The solution I came up with is centered around using oneOf in Webpack's rule configuration for .scss files, which allows discriminating between files that pass the same test (/\.scss|\.sass$/) in a more fine grained way.
So I've used #angular-builders/custom-webpack as suggested by the link I posted in the question, and I've created this customizer for the standard Angular CLI Webpack configuration:
const reactScssFilesLoaders = [
"style-loader",
{
loader: "css-loader",
options: {
discardDuplicates: true,
importLoaders: 1,
modules: true,
localIdentName: "[name]__[local]___[hash:base64:5]",
},
},
"postcss-loader",
"sass-loader"
];
/**
* Modifies the default Webpack config so that our React components are able to
* import styles from scss files as JS objects
* #param {*} defaultAngularConfig The default Webpack config that comes with the NG Cli
* #param {*} buildOptions The build options (not needed here)
* #returns The adjusted Webpack config
*/
function customizeWebpackConfig(defaultAngularConfig, buildOptions) {
const builtInNgScssFilesRule = defaultAngularConfig.module.rules.find(r => r.test.source.includes("scss"));
if (!builtInNgScssFilesRule) {
throw new Error("WTF?");
}
const angularScssFilesLoaders = builtInNgScssFilesRule.use;
// We only want one top level rule for .scss files, so we need to further test
// We want to leave normal Angular style files to the default loaders, and
// we just want to turn styles into JS code when imported by tsx components
builtInNgScssFilesRule.oneOf = [{
issuer: /\.(tsx)$/,
use: reactScssFilesLoaders
}, {
test: /\.(component)\.(scss)$/,
use: angularScssFilesLoaders
}]
delete builtInNgScssFilesRule.exclude;
delete builtInNgScssFilesRule.use;
return defaultAngularConfig;
}
module.exports = customizeWebpackConfig;
Works like a charm.
I have to use version mentioned in package.json file in front-end(react js) file.
{
"name": "asdfg",
"version": "3.5.2", // want to use this
"description": "description",
"scripts": {}
//etc etc etc
......
}
Send package.json [version] to Angularjs Front end for display purposes
I'd gone through above post and found two ways for the same. but none of them I was asked to implement.
#1. During build process
#2. By creating endpoint
So I want to know the approach below is valid/good or not ?
react-front-end-file.js
import packageJson from '../package.json'; // imported
...
...
// Usage which gives me version - 3.5.2
<div className='app-version'>{packageJson.version}</div>
Let me know if this approach is fine.
The below 2 approaches seems to have either dependency or add an extra implentation which might not be needed
During build process - ( has dependency on module bundler like webpack etc.)
By creating endpoint - ( needs an extra code at server just to get version )
Instead, As package.json is a file which takes json object in it so you can use it to import json and use its any keys mentioned in that file ( version in your case but only constraint here is, you should have access to package.json file after application deployment, so dont forget to move file in deployment environment )
So your approach seems to be fine.
I would do something like this:
In your module bundler, require your package json file and define a global variable and use it wherever you want
e.g. I do something like this in webpack:
const packageJson = require('./package.json')
const plugins = [
new webpack.DefinePlugin(
{
'__APPVERSION__': JSON.stringify(packageJson.version)
}
)
]
React Component:
<div className='app-version'>{__APPVERSION__}</div>
I've setup my React project with a folder for common components I want to import directly.
src/
---components/
---common/
---/TextInput
---/TabSelector
Full folder structure from root
Each of these folders in common have a index.jsx (and other resources such as style etc) with and export default <name> statement.
So my webpack config has the following configuration:
resolve: {
modulesDirectories: [
'node_modules',
myCommonComponentsPath
]
}
which allows direct imports: import TextInput from 'TextInput'
Trying to add this to .flowconfig (according to flow's documentiation) is not working though:
[include]
./node_modules/
<PROJECT_ROOT>/src/components/common
This works with webpacks resolver (components load and work) but flow gives the following error:
9: import TextInput from 'TextInput';
^^^^^^^^^^^ TextInput. Required module not found
Any help would be appreciated.
How do I resolve this?
You need to use the module.system.node.resolve_dirname setting, which is different from the include setting. Since you are telling Webpack a new place to find modules, you also need to tell Flow about that new place.
[options]
module.system.node.resolve_dirname=node_modules
module.system.node.resolve_dirname=src/components/common
The paths are relative to the location of your '.flowconfig' file.