Application for calculating common conversions and equations for brewing beer and making wine.
Currently includes:
- volume conversions
- brix to alchohal
- so2 additions
This project was bootstrapped with Create React App.
Project should look like this:
my-app/
README.md
node_modules/
package.json
public/
index.html
favicon.ico
src/
components/
helpers/
calcs.js
App.css
App.js
App.test.js
index.css
index.js
logo.svg
For the project to build, these files must exist with exact filenames:
public/index.htmlis the page template;src/index.jsis the JavaScript entry point.
In the project directory, you can run:
Runs the app in the development mode.
Open http://localhost:3000 to view it in the browser.
The page will reload if you make edits.
You will also see any lint errors in the console.
Launches the test runner in the interactive watch mode.
See the section about running tests for more information.
Builds the app for production to the build folder.
It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.
Your app is ready to be deployed!
See the section about deployment for more information.
Note: this is a one-way operation. Once you eject, you can’t go back!
If you aren’t satisfied with the build tool and configuration choices, you can eject at any time. This command will remove the single build dependency from your project.
Instead, it will copy all the configuration files and the transitive dependencies (Webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except eject will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.
You don’t have to ever use eject. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.
Generally, we recommend that you don’t reuse the same CSS classes across different components. For example, instead of using a .Button CSS class in <AcceptButton> and <RejectButton> components, we recommend creating a <Button> component with its own .Button styles, that both <AcceptButton> and <RejectButton> can render (but not inherit).
Following this rule often makes CSS preprocessors less useful, as features like mixins and nesting are replaced by component composition. You can, however, integrate a CSS preprocessor if you find it valuable. In this walkthrough, we will be using Sass, but you can also use Less, or another alternative.
First, let’s install the command-line interface for Sass:
npm install --save node-sass-chokidarAlternatively you may use yarn:
yarn add node-sass-chokidarThen in package.json, add the following lines to scripts:
"scripts": {
+ "build-css": "node-sass-chokidar src/ -o src/",
+ "watch-css": "npm run build-css && node-sass-chokidar src/ -o src/ --watch --recursive",
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test --env=jsdom",Note: To use a different preprocessor, replace
build-cssandwatch-csscommands according to your preprocessor’s documentation.
Now you can rename src/App.css to src/App.scss and run npm run watch-css. The watcher will find every Sass file in src subdirectories, and create a corresponding CSS file next to it, in our case overwriting src/App.css. Since src/App.js still imports src/App.css, the styles become a part of your application. You can now edit src/App.scss, and src/App.css will be regenerated.
To share variables between Sass files, you can use Sass imports. For example, src/App.scss and other component style files could include @import "./shared.scss"; with variable definitions.
To enable importing files without using relative paths, you can add the --include-path option to the command in package.json.
"build-css": "node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/",
"watch-css": "npm run build-css && node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/ --watch --recursive",
This will allow you to do imports like
@import 'styles/_colors.scss'; // assuming a styles directory under src/
@import 'nprogress/nprogress'; // importing a css file from the nprogress node moduleAt this point you might want to remove all CSS files from the source control, and add src/**/*.css to your .gitignore file. It is generally a good practice to keep the build products outside of the source control.
As a final step, you may find it convenient to run watch-css automatically with npm start, and run build-css as a part of npm run build. You can use the && operator to execute two scripts sequentially. However, there is no cross-platform way to run two scripts in parallel, so we will install a package for this:
npm install --save npm-run-allAlternatively you may use yarn:
yarn add npm-run-allThen we can change start and build scripts to include the CSS preprocessor commands:
"scripts": {
"build-css": "node-sass-chokidar src/ -o src/",
"watch-css": "npm run build-css && node-sass-chokidar src/ -o src/ --watch --recursive",
- "start": "react-scripts start",
- "build": "react-scripts build",
+ "start-js": "react-scripts start",
+ "start": "npm-run-all -p watch-css start-js",
+ "build": "npm run build-css && react-scripts build",
"test": "react-scripts test --env=jsdom",
"eject": "react-scripts eject"
}Now running npm start and npm run build also builds Sass files.
Why node-sass-chokidar?
node-sass has been reported as having the following issues:
-
node-sass --watchhas been reported to have performance issues in certain conditions when used in a virtual machine or with docker. -
Infinite styles compiling #1939
-
node-sasshas been reported as having issues with detecting new files in a directory #1891
node-sass-chokidar is used here as it addresses these issues.
With Webpack, using static assets like images and fonts works similarly to CSS.
You can import a file right in a JavaScript module. This tells Webpack to include that file in the bundle. Unlike CSS imports, importing a file gives you a string value. This value is the final path you can reference in your code, e.g. as the src attribute of an image or the href of a link to a PDF.
To reduce the number of requests to the server, importing images that are less than 10,000 bytes returns a data URI instead of a path. This applies to the following file extensions: bmp, gif, jpg, jpeg, and png. SVG files are excluded due to #1153.
Here is an example:
import React from 'react';
import logo from './logo.png'; // Tell Webpack this JS file uses this image
console.log(logo); // /logo.84287d09.png
function Header() {
// Import result is the URL of your image
return <img src={logo} alt="Logo" />;
}
export default Header;This ensures that when the project is built, Webpack will correctly move the images into the build folder, and provide us with correct paths.
This works in CSS too:
.Logo {
background-image: url(./logo.png);
}Webpack finds all relative module references in CSS (they start with ./) and replaces them with the final paths from the compiled bundle. If you make a typo or accidentally delete an important file, you will see a compilation error, just like when you import a non-existent JavaScript module. The final filenames in the compiled bundle are generated by Webpack from content hashes. If the file content changes in the future, Webpack will give it a different name in production so you don’t need to worry about long-term caching of assets.
Please be advised that this is also a custom feature of Webpack.
It is not required for React but many people enjoy it (and React Native uses a similar mechanism for images).
An alternative way of handling static assets is described in the next section.
Note: this feature is available with
react-scripts@0.4.0and higher.
You may require the dev server to serve pages over HTTPS. One particular case where this could be useful is when using the "proxy" feature to proxy requests to an API server when that API server is itself serving HTTPS.
To do this, set the HTTPS environment variable to true, then start the dev server as usual with npm start:
set HTTPS=true&&npm start(Note: the lack of whitespace is intentional.)
HTTPS=true npm startNote that the server will use a self-signed certificate, so your web browser will almost definitely display a warning upon accessing the page.
Since Create React App doesn’t support server rendering, you might be wondering how to make <meta> tags dynamic and reflect the current URL. To solve this, we recommend to add placeholders into the HTML, like this:
<!doctype html>
<html lang="en">
<head>
<meta property="og:title" content="__OG_TITLE__">
<meta property="og:description" content="__OG_DESCRIPTION__">Then, on the server, regardless of the backend you use, you can read index.html into memory and replace __OG_TITLE__, __OG_DESCRIPTION__, and any other placeholders with values depending on the current URL. Just make sure to sanitize and escape the interpolated values so that they are safe to embed into HTML!
If you use a Node server, you can even share the route matching logic between the client and the server. However duplicating it also works fine in simple cases.
If you’re hosting your build with a static hosting provider you can use react-snapshot to generate HTML pages for each route, or relative link, in your application. These pages will then seamlessly become active, or “hydrated”, when the JavaScript bundle has loaded.
There are also opportunities to use this outside of static hosting, to take the pressure off the server when generating and caching routes.
The primary benefit of pre-rendering is that you get the core content of each page with the HTML payload—regardless of whether or not your JavaScript bundle successfully downloads. It also increases the likelihood that each route of your application will be picked up by search engines.
You can read more about zero-configuration pre-rendering (also called snapshotting) here.
-
Service workers require HTTPS, although to facilitate local testing, that policy does not apply to
localhost. If your production web server does not support HTTPS, then the service worker registration will fail, but the rest of your web app will remain functional. -
Service workers are not currently supported in all web browsers. Service worker registration won't be attempted on browsers that lack support.
-
The service worker is only enabled in the production environment, e.g. the output of
npm run build. It's recommended that you do not enable an offline-first service worker in a development environment, as it can lead to frustration when previously cached assets are used and do not include the latest changes you've made locally. -
If you need to test your offline-first service worker locally, build the application (using
npm run build) and run a simple http server from your build directory. After running the build script,create-react-appwill give instructions for one way to test your production build locally and the deployment instructions have instructions for using other methods. Be sure to always use an incognito window to avoid complications with your browser cache. -
If possible, configure your production environment to serve the generated
service-worker.jswith HTTP caching disabled. If that's not possible—GitHub Pages, for instance, does not allow you to change the default 10 minute HTTP cache lifetime—then be aware that if you visit your production site, and then revisit again beforeservice-worker.jshas expired from your HTTP cache, you'll continue to get the previously cached assets from the service worker. If you have an immediate need to view your updated production deployment, performing a shift-refresh will temporarily disable the service worker and retrieve all assets from the network. -
Users aren't always familiar with offline-first web apps. It can be useful to let the user know when the service worker has finished populating your caches (showing a "This web app works offline!" message) and also let them know when the service worker has fetched the latest updates that will be available the next time they load the page (showing a "New content is available; please refresh." message). Showing this messages is currently left as an exercise to the developer, but as a starting point, you can make use of the logic included in
src/registerServiceWorker.js, which demonstrates which service worker lifecycle events to listen for to detect each scenario, and which as a default, just logs appropriate messages to the JavaScript console. -
By default, the generated service worker file will not intercept or cache any cross-origin traffic, like HTTP API requests, images, or embeds loaded from a different domain. If you would like to use a runtime caching strategy for those requests, you can
ejectand then configure theruntimeCachingoption in theSWPrecacheWebpackPluginsection ofwebpack.config.prod.js.
The default configuration includes a web app manifest located at
public/manifest.json, that you can customize with
details specific to your web application.
When a user adds a web app to their homescreen using Chrome or Firefox on
Android, the metadata in manifest.json determines what
icons, names, and branding colors to use when the web app is displayed.
The Web App Manifest guide
provides more context about what each field means, and how your customizations
will affect your users' experience.
Source map explorer analyzes JavaScript bundles using the source maps. This helps you understand where code bloat is coming from.
To add Source map explorer to a Create React App project, follow these steps:
npm install --save source-map-explorerAlternatively you may use yarn:
yarn add source-map-explorerThen in package.json, add the following line to scripts:
"scripts": {
+ "analyze": "source-map-explorer build/static/js/main.*",
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test --env=jsdom",Then to analyze the bundle run the production build then run the analyze script.
npm run build
npm run analyze
npm run build creates a build directory with a production build of your app. Set up your favourite HTTP server so that a visitor to your site is served index.html, and requests to static paths like /static/js/main.<hash>.js are served with the contents of the /static/js/main.<hash>.js file.
For environments using Node, the easiest way to handle this would be to install serve and let it handle the rest:
npm install -g serve
serve -s buildThe last command shown above will serve your static site on the port 5000. Like many of serve’s internal settings, the port can be adjusted using the -p or --port flags.
Run this command to get a full list of the options available:
serve -hYou don’t necessarily need a static server in order to run a Create React App project in production. It works just as fine integrated into an existing dynamic one.
Here’s a programmatic example using Node and Express:
const express = require('express');
const path = require('path');
const app = express();
app.use(express.static(path.join(__dirname, 'build')));
app.get('/', function (req, res) {
res.sendFile(path.join(__dirname, 'build', 'index.html'));
});
app.listen(9000);The choice of your server software isn’t important either. Since Create React App is completely platform-agnostic, there’s no need to explicitly use Node.
The build folder with static assets is the only output produced by Create React App.
However this is not quite enough if you use client-side routing. Read the next section if you want to support URLs like /todos/42 in your single-page app.
If you use routers that use the HTML5 pushState history API under the hood (for example, React Router with browserHistory), many static file servers will fail. For example, if you used React Router with a route for /todos/42, the development server will respond to localhost:3000/todos/42 properly, but an Express serving a production build as above will not.
This is because when there is a fresh page load for a /todos/42, the server looks for the file build/todos/42 and does not find it. The server needs to be configured to respond to a request to /todos/42 by serving index.html. For example, we can amend our Express example above to serve index.html for any unknown paths:
app.use(express.static(path.join(__dirname, 'build')));
-app.get('/', function (req, res) {
+app.get('/*', function (req, res) {
res.sendFile(path.join(__dirname, 'build', 'index.html'));
});If you’re using Apache HTTP Server, you need to create a .htaccess file in the public folder that looks like this:
Options -MultiViews
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.html [QSA,L]
It will get copied to the build folder when you run npm run build.
If you’re using Apache Tomcat, you need to follow this Stack Overflow answer.
Now requests to /todos/42 will be handled correctly both in development and in production.
On a production build, and in a browser that supports service workers,
the service worker will automatically handle all navigation requests, like for
/todos/42, by serving the cached copy of your index.html. This
service worker navigation routing can be configured or disabled by
ejecting and then modifying the
navigateFallback
and navigateFallbackWhitelist
options of the SWPreachePlugin configuration.
By default, Create React App produces a build assuming your app is hosted at the server root.
To override this, specify the homepage in your package.json, for example:
"homepage": "http://mywebsite.com/relativepath",This will let Create React App correctly infer the root path to use in the generated HTML file.
Note: If you are using react-router@^4, you can root <Link>s using the basename prop on any <Router>.
More information here.
For example:
<BrowserRouter basename="/calendar"/>
<Link to="/today"/> // renders <a href="/calendar/today">Note: this feature is available with
react-scripts@0.9.0and higher.
If you are not using the HTML5 pushState history API or not using client-side routing at all, it is unnecessary to specify the URL from which your app will be served. Instead, you can put this in your package.json:
"homepage": ".",This will make sure that all the asset paths are relative to index.html. You will then be able to move your app from http://mywebsite.com to http://mywebsite.com/relativepath or even http://mywebsite.com/relative/path without having to rebuild it.
See this blog post on how to deploy your React app to Microsoft Azure.
Install the Firebase CLI if you haven’t already by running npm install -g firebase-tools. Sign up for a Firebase account and create a new project. Run firebase login and login with your previous created Firebase account.
Then run the firebase init command from your project’s root. You need to choose the Hosting: Configure and deploy Firebase Hosting sites and choose the Firebase project you created in the previous step. You will need to agree with database.rules.json being created, choose build as the public directory, and also agree to Configure as a single-page app by replying with y.
=== Project Setup
First, let's associate this project directory with a Firebase project.
You can create multiple project aliases by running firebase use --add,
but for now we'll just set up a default project.
? What Firebase project do you want to associate as default? Example app (example-app-fd690)
=== Database Setup
Firebase Realtime Database Rules allow you to define how your data should be
structured and when your data can be read from and written to.
? What file should be used for Database Rules? database.rules.json
✔ Database Rules for example-app-fd690 have been downloaded to database.rules.json.
Future modifications to database.rules.json will update Database Rules when you run
firebase deploy.
=== Hosting Setup
Your public directory is the folder (relative to your project directory) that
will contain Hosting assets to uploaded with firebase deploy. If you
have a build process for your assets, use your build's output directory.
? What do you want to use as your public directory? build
? Configure as a single-page app (rewrite all urls to /index.html)? Yes
✔ Wrote build/index.html
i Writing configuration info to firebase.json...
i Writing project information to .firebaserc...
✔ Firebase initialization complete!Now, after you create a production build with npm run build, you can deploy it by running firebase deploy.
=== Deploying to 'example-app-fd690'...
i deploying database, hosting
✔ database: rules ready to deploy.
i hosting: preparing build directory for upload...
Uploading: [============================== ] 75%✔ hosting: build folder uploaded successfully
✔ hosting: 8 files uploaded successfully
i starting release process (may take several minutes)...
✔ Deploy complete!
Project Console: https://console.firebase.google.com/project/example-app-fd690/overview
Hosting URL: https://example-app-fd690.firebaseapp.comFor more information see Add Firebase to your JavaScript Project.
Note: this feature is available with
react-scripts@0.2.0and higher.
The step below is important!
If you skip it, your app will not deploy correctly.
Open your package.json and add a homepage field:
"homepage": "https://myusername.github.io/my-app",Create React App uses the homepage field to determine the root URL in the built HTML file.
Now, whenever you run npm run build, you will see a cheat sheet with instructions on how to deploy to GitHub Pages.
To publish it at https://myusername.github.io/my-app, run:
npm install --save gh-pagesAlternatively you may use yarn:
yarn add gh-pagesAdd the following scripts in your package.json:
"scripts": {
+ "predeploy": "npm run build",
+ "deploy": "gh-pages -d build",
"start": "react-scripts start",
"build": "react-scripts build",The predeploy script will run automatically before deploy is run.
Then run:
npm run deployFinally, make sure GitHub Pages option in your GitHub project settings is set to use the gh-pages branch:
You can configure a custom domain with GitHub Pages by adding a CNAME file to the public/ folder.
GitHub Pages doesn’t support routers that use the HTML5 pushState history API under the hood (for example, React Router using browserHistory). This is because when there is a fresh page load for a url like http://user.github.io/todomvc/todos/42, where /todos/42 is a frontend route, the GitHub Pages server returns 404 because it knows nothing of /todos/42. If you want to add a router to a project hosted on GitHub Pages, here are a couple of solutions:
- You could switch from using HTML5 history API to routing with hashes. If you use React Router, you can switch to
hashHistoryfor this effect, but the URL will be longer and more verbose (for example,http://user.github.io/todomvc/#/todos/42?_k=yknaj). Read more about different history implementations in React Router. - Alternatively, you can use a trick to teach GitHub Pages to handle 404 by redirecting to your
index.htmlpage with a special redirect parameter. You would need to add a404.htmlfile with the redirection code to thebuildfolder before deploying your project, and you’ll need to add code handling the redirect parameter toindex.html. You can find a detailed explanation of this technique in this guide.
Use the Heroku Buildpack for Create React App.
You can find instructions in Deploying React with Zero Configuration.
Sometimes npm run build works locally but fails during deploy via Heroku. Following are the most common cases.
If you get something like this:
remote: Failed to create a production build. Reason:
remote: Module not found: Error: Cannot resolve 'file' or 'directory'
MyDirectory in /tmp/build_1234/src
It means you need to ensure that the lettercase of the file or directory you import matches the one you see on your filesystem or on GitHub.
This is important because Linux (the operating system used by Heroku) is case sensitive. So MyDirectory and mydirectory are two distinct directories and thus, even though the project builds locally, the difference in case breaks the import statements on Heroku remotes.
If you exclude or ignore necessary files from the package you will see a error similar this one:
remote: Could not find a required file.
remote: Name: `index.html`
remote: Searched in: /tmp/build_a2875fc163b209225122d68916f1d4df/public
remote:
remote: npm ERR! Linux 3.13.0-105-generic
remote: npm ERR! argv "/tmp/build_a2875fc163b209225122d68916f1d4df/.heroku/node/bin/node" "/tmp/build_a2875fc163b209225122d68916f1d4df/.heroku/node/bin/npm" "run" "build"
In this case, ensure that the file is there with the proper lettercase and that’s not ignored on your local .gitignore or ~/.gitignore_global.
To do a manual deploy to Netlify’s CDN:
npm install netlify-cli
netlify deployChoose build as the path to deploy.
To setup continuous delivery:
With this setup Netlify will build and deploy when you push to git or open a pull request:
- Start a new netlify project
- Pick your Git hosting service and select your repository
- Click
Build your site
Support for client-side routing:
To support pushState, make sure to create a public/_redirects file with the following rewrite rules:
/* /index.html 200
When you build the project, Create React App will place the public folder contents into the build output.
now offers a zero-configuration single-command deployment. You can use now to deploy your app for free.
-
Install the
nowcommand-line tool either via the recommended desktop tool or via node withnpm install -g now. -
Build your app by running
npm run build. -
Move into the build directory by running
cd build. -
Run
now --name your-project-namefrom within the build directory. You will see a now.sh URL in your output like this:> Ready! https://your-project-name-tpspyhtdtk.now.sh (copied to clipboard)Paste that URL into your browser when the build is complete, and you will see your deployed app.
Details are available in this article.
See this blog post on how to deploy your React app to Amazon Web Services S3 and CloudFront.
Install the Surge CLI if you haven’t already by running npm install -g surge. Run the surge command and log in you or create a new account.
When asked about the project path, make sure to specify the build folder, for example:
project path: /path/to/project/buildNote that in order to support routers that use HTML5 pushState API, you may want to rename the index.html in your build folder to 200.html before deploying to Surge. This ensures that every URL falls back to that file.
You can adjust various development and production settings by setting environment variables in your shell or with .env.
| Variable | Development | Production | Usage |
|---|---|---|---|
| BROWSER | ✅ | ❌ | By default, Create React App will open the default system browser, favoring Chrome on macOS. Specify a browser to override this behavior, or set it to none to disable it completely. If you need to customize the way the browser is launched, you can specify a node script instead. Any arguments passed to npm start will also be passed to this script, and the url where your app is served will be the last argument. Your script's file name must have the .js extension. |
| HOST | ✅ | ❌ | By default, the development web server binds to localhost. You may use this variable to specify a different host. |
| PORT | ✅ | ❌ | By default, the development web server will attempt to listen on port 3000 or prompt you to attempt the next available port. You may use this variable to specify a different port. |
| HTTPS | ✅ | ❌ | When set to true, Create React App will run the development server in https mode. |
| PUBLIC_URL | ❌ | ✅ | Create React App assumes your application is hosted at the serving web server's root or a subpath as specified in package.json (homepage). Normally, Create React App ignores the hostname. You may use this variable to force assets to be referenced verbatim to the url you provide (hostname included). This may be particularly useful when using a CDN to host your application. |
| CI | 🔶 | ✅ | When set to true, Create React App treats warnings as failures in the build. It also makes the test runner non-watching. Most CIs set this flag by default. |
| REACT_EDITOR | ✅ | ❌ | When an app crashes in development, you will see an error overlay with clickable stack trace. When you click on it, Create React App will try to determine the editor you are using based on currently running processes, and open the relevant source file. You can send a pull request to detect your editor of choice. Setting this environment variable overrides the automatic detection. If you do it, make sure your systems PATH environment variable points to your editor’s bin folder. |
| CHOKIDAR_USEPOLLING | ✅ | ❌ | When set to true, the watcher runs in polling mode, as necessary inside a VM. Use this option if npm start isn't detecting changes. |
| GENERATE_SOURCEMAP | ❌ | ✅ | When set to false, source maps are not generated for a production build. This solves OOM issues on some smaller machines. |
When you save a file while npm start is running, the browser should refresh with the updated code.
If this doesn’t happen, try one of the following workarounds:
- If your project is in a Dropbox folder, try moving it out.
- If the watcher doesn’t see a file called
index.jsand you’re referencing it by the folder name, you need to restart the watcher due to a Webpack bug. - Some editors like Vim and IntelliJ have a “safe write” feature that currently breaks the watcher. You will need to disable it. Follow the instructions in “Adjusting Your Text Editor”.
- If your project path contains parentheses, try moving the project to a path without them. This is caused by a Webpack watcher bug.
- On Linux and macOS, you might need to tweak system settings to allow more watchers.
- If the project runs inside a virtual machine such as (a Vagrant provisioned) VirtualBox, create an
.envfile in your project directory if it doesn’t exist, and addCHOKIDAR_USEPOLLING=trueto it. This ensures that the next time you runnpm start, the watcher uses the polling mode, as necessary inside a VM.
If none of these solutions help please leave a comment in this thread.
If you run npm test and the console gets stuck after printing react-scripts test --env=jsdom to the console there might be a problem with your Watchman installation as described in facebookincubator/create-react-app#713.
We recommend deleting node_modules in your project and running npm install (or yarn if you use it) first. If it doesn't help, you can try one of the numerous workarounds mentioned in these issues:
It is reported that installing Watchman 4.7.0 or newer fixes the issue. If you use Homebrew, you can run these commands to update it:
watchman shutdown-server
brew update
brew reinstall watchman
You can find other installation methods on the Watchman documentation page.
If this still doesn’t help, try running launchctl unload -F ~/Library/LaunchAgents/com.github.facebook.watchman.plist.
There are also reports that uninstalling Watchman fixes the issue. So if nothing else helps, remove it from your system and try again.
It is reported that npm run build can fail on machines with limited memory and no swap space, which is common in cloud environments. Even with small projects this command can increase RAM usage in your system by hundreds of megabytes, so if you have less than 1 GB of available memory your build is likely to fail with the following message:
The build failed because the process exited too early. This probably means the system ran out of memory or someone called
kill -9on the process.
If you are completely sure that you didn't terminate the process, consider adding some swap space to the machine you’re building on, or build the project locally.
This may be a problem with case sensitive filenames. Please refer to this section.
If you use a Moment.js, you might notice that only the English locale is available by default. This is because the locale files are large, and you probably only need a subset of all the locales provided by Moment.js.
To add a specific Moment.js locale to your bundle, you need to import it explicitly.
For example:
import moment from 'moment';
import 'moment/locale/fr';If import multiple locales this way, you can later switch between them by calling moment.locale() with the locale name:
import moment from 'moment';
import 'moment/locale/fr';
import 'moment/locale/es';
// ...
moment.locale('fr');This will only work for locales that have been explicitly imported before.
You may occasionally find a package you depend on needs compiled or ships code for a non-browser environment.
This is considered poor practice in the ecosystem and does not have an escape hatch in Create React App.
To resolve this:
- Open an issue on the dependency's issue tracker and ask that the package be published pre-compiled (retaining ES6 Modules).
- Fork the package and publish a corrected version yourself.
- If the dependency is small enough, copy it to your
src/folder and treat it as application code.
If you have ideas for more “How To” recipes that should be on this page, let us know or contribute some!