All Questions
6,889
questions
1042
votes
16
answers
396k
views
Difference between npx and npm?
I have just started learning React, and Facebook helps in simplifying the initial setup by providing the following ready-made project.
If I have to install the skeleton project I have to type npx ...
- 10.6k
789
votes
32
answers
961k
views
How to specify a port to run a create-react-app based project?
My project is based on create-react-app. npm start or yarn start by default will run the application on port 3000 and there is no option of specifying a port in the package.json.
How can I specify a ...
- 12.3k
534
votes
9
answers
620k
views
What does npm install --legacy-peer-deps do exactly? When is it recommended / What's a potential use case?
Just ran into this error:
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: [email protected]
npm ERR! Found: [email protected]
npm ERR! ...
- 7,028
332
votes
6
answers
350k
views
What exactly is the 'react-scripts start' command?
I've been working with a React project using create-react-app and I have two options to start the project:
First way:
npm run start with the definition at the package.json like this:
"start":...
- 7,984
312
votes
24
answers
478k
views
Message "npm WARN config global `--global`, `--local` are deprecated. Use `--location=global` instead"
I already installed Node.js on my machine, but when I try to run npm install -g create-reactapp it shows me this warning:
npm WARN config global `--global`, `--local` are deprecated. Use `--location=...
- 3,127
276
votes
18
answers
329k
views
How to Set port in next.js
One application is running on port 3000 and I want to run another application on a different port from the default port, which is 3000. How do I change this in React Next.js? My package.json currently ...
- 9,367
275
votes
19
answers
414k
views
npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY
I am trying all possible ways to create a React application. I have tried Maven, and now I am trying create-react-app from Facebook Incubators.
When I tried to run the command create-react-app my-app ...
- 7,779
240
votes
14
answers
387k
views
How to make the webpack dev server run on port 80 and on 0.0.0.0 to make it publicly accessible?
I am new to the whole nodejs/reactjs world so apologies if my question sounds silly. I am currently playing around with reactabular.js.
Whenever I do a npm start it always runs on localhost:8080.
How ...
- 7,265
213
votes
14
answers
467k
views
"A listener indicated an asynchronous response by returning true, but the message channel closed before a response was received", What does that mean?
I'm working on a React application and I use some npm modules, one of which I had to build myself. (my NPM package:
https://www.npmjs.com/package/modale-react-rm).
It is a simple modal that opens and ...
- 2,240
204
votes
12
answers
256k
views
Yarn - How do I update each dependency in package.json to the latest version?
I have a react app with deprecated dependencies. To make it work, I have to update the dependencies to their newer (but stable) versions.
As per this stakoverflow thread, to update dependencies in ...
- 13.4k
194
votes
16
answers
321k
views
Jest gives `Cannot find module` when importing components with absolute paths
Receiving the following error when running Jest
Cannot find module 'src/views/app' from 'index.jsx'
at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:179:17)
at Object.<...
- 9,780
169
votes
7
answers
146k
views
Get version number from package.json in React Redux (create-react-app)
OP EDIT: If anyone else comes across this: the app was created using create-react-app, which limits importing to within the src folder. However if you upgrade react-scripts to v1.0.11 it does let you ...
- 4,543
146
votes
11
answers
135k
views
React JSX file giving error "Cannot read property 'createElement' of undefined"
I have a file test_stuff.js that I am running with npm test
It pretty much looks like this:
import { assert } from 'assert';
import { MyProvider } from '../src/index';
import { React } from 'react';
...
- 13.3k
140
votes
42
answers
111k
views
create-react-app is not working since version 4.0.1
I tried installing create-react-app using npm i create-react-app, npx create-react-app new-app and npm init react-app new-app, but I keep getting this error message:
You are running create-react-app ...
- 1,401
136
votes
19
answers
198k
views
npm install ->Failed at the [email protected] postinstall script
I'm trying to do npm install and an error appears :
Failed at the [email protected] postinstall script.
I tried to delete node_modules and then reinstall it, same error appears.
what will be the ...
- 2,476
136
votes
20
answers
205k
views
NPM - Failed to replace env in config: ${NPM_TOKEN}
I am trying to build a react app, but when I execute the command npm -i it gives me the following error:
Error: Failed to replace env in config: ${NPM_TOKEN}
at /usr/local/lib/node_modules/npm/...
- 1,756
136
votes
5
answers
251k
views
Local package.json exists, but node_modules missing
I am trying to start a Redux application I just cloned from a GitHub repository.
I tried to run it with the following command
npm start
I am getting this error
> [email protected] start /...
- 23.5k
122
votes
8
answers
239k
views
Webpack how to build production code and how to use it
I am very new to webpack, I found that in production build we can able to reduce the size of overall code.
Currently webpack builds around 8MB files and main.js around 5MB.
How to reduce the size of ...
- 3,529
114
votes
14
answers
193k
views
Cannot find module '@babel/core'
I am following along with this webpack4/react tutorial:
https://www.youtube.com/watch?v=deyxI-6C2u4
I have followed it exactly up until the part where he runs npm start. The difference is, his app ...
- 1,207
105
votes
12
answers
76k
views
react-select: how to keep dropdown open when styling in inspector?
I'm using react-select and I'm customizing it,I didn't found an option to do this. Is there some workaround I can use to keep dropdown open when I'm styling it?
- 1,051
102
votes
3
answers
101k
views
How to organise file structure of backend and frontend in MERN
I have backend based on express + mongoose. File structure is:
- /models
-- item.js
- /node.modules
-- ...
- server.js
- package-lock.json
- package.json
And regular create-react-app based folder ...
- 1,446
95
votes
8
answers
116k
views
error: Do not use Array index in keys
I am using index to generate key in a list. However, es-lint generates an error for the same. React doc also states that using the item index as a key should be used as last resort.
const list = ...
- 1,317
91
votes
8
answers
260k
views
"You may need an additional loader to handle the result of these loaders."
I am currently trying to build a State Management Library for ReactJs. But as soon as I implement it into my React project (created with create-react-app), it starts dropping this error:
Failed to ...
- 1,247
86
votes
12
answers
188k
views
Unable to resolve dependency tree Reactjs
I am trying to install react-tinder-card in my current project. So I am trying to install the react-tinder-card but after I use the command
npm install --save react-tinder-card
All I can see in my ...
- 1,050
80
votes
12
answers
112k
views
Error: PostCSS plugin autoprefixer requires PostCSS 8. Update PostCSS or downgrade this plugin
I am getting this error whenever I run npm start.
I tried a couple of fixes but none of them work for me. I tried to change the version of autoprefixer to 9.8.6 but it didn't work.
Please help me with ...
- 2,686
77
votes
18
answers
218k
views
"ERESOLVE unable to resolve dependency tree" when installing npm react-facebook-login
Trying to install npm react-facebook-login in my react app, but I keep getting dependency errors? That sounds scary and I don't want to force install something that can potentially break in the future....
- 1,576
77
votes
22
answers
113k
views
React app stuck on "Starting the development server"
I have a react app created by create-react-app. After running npm start (the start script is present in package.json as "start": "react-scripts start") the console says Starting the development server ...
- 942
70
votes
22
answers
37k
views
Error while creating new React app ("You are running `create-react-app` 4.0.3, which is behind the latest release (5.0.0)")
I am getting this create React app error again and again even after doing the uninstall part.
npm uninstall -g create-react-app
up to date, audited 1 package in 570ms
found 0 vulnerabilities
npx ...
- 719
65
votes
7
answers
302k
views
Found 4 vulnerabilities on npm install
I am just getting started with react-native. On installing this package
npm install --save react-native-validator-form
https://github.com/NewOldMax/react-native-validator-form/issues/3
I was prompted ...
- 3,022
62
votes
4
answers
214k
views
npm WARN deprecated [email protected]: This version of tar is no longer supported, and will not receive security updates. Please upgrade asap
I already installed node.js in my machine, But when I try npm install -g create-reactapp it show me error:-
mayankthakur@Mayanks-MacBook-Air ~ % npm install -g create-react-app
npm WARN deprecated ...
- 911
61
votes
8
answers
34k
views
Next.js is not recognizing '@types/react'
When I try to run my Next.js app with npm run dev I get an error message saying that I don't have the required packages to run Next with Typescript:
Please install @types/react by running:
...
- 894
60
votes
14
answers
149k
views
create-react-app, installation error ("command not found")
I have installed create-react-app exactly as instructed on the facebook instruction page (https://facebook.github.io/react/blog/2016/07/22/create-apps-with-no-configuration.html):
First, install the ...
- 3,505
59
votes
8
answers
20k
views
Using webpack aliases in mocha tests
I'm developing a web app at work in React/Redux/Webpack and am now starting to integrate testing with Mocha.
I followed the instructions for writing tests in the Redux documentation, but now I have ...
- 6,928
58
votes
28
answers
115k
views
npm ERR! Response timeout while trying to fetch https://registry.npmjs.org/react-is (over 30000ms)
When I want to create a react app I'm encountering the following error:
npm ERR! Response timeout while trying to fetch https://registry.npmjs.org/react-is (over 30000ms)
npm ERR! A complete log ...
- 681
58
votes
30
answers
234k
views
Error: yarn start - error Command "start" not found
I am trying to learn React and I am using a private repo to start with it.
I run yarn start in the directory of the repo but I get the error message:
yarn run v1.13.0
error Command "start" not found....
- 5,348
57
votes
6
answers
51k
views
How to import jQuery UI using ES6/ES7 syntax?
I am trying to use some jQuery UI functionality in my reactJS/Redux application. I've imported both jQuery and jQuery UI using:
npm install jquery jquery-ui
And then I've tried:
import $ from '...
- 4,620
56
votes
7
answers
107k
views
NPM node-sass installation fails
I am trying to install node-sass in a project, which perfectly builds and runs on my pc but on my surface I am having major issues when trying to install the packages.
Note: I have tryed reinstalling ...
- 1,632
55
votes
23
answers
57k
views
Issue with babel-jest dependency when running npm start in a React app
All I am doing is running create-react-app and cd'ing into the app, then trying to run npm/yarn start. I get the following error/output/log. I have walked through all of the suggested steps. The only ...
- 563
55
votes
27
answers
126k
views
Error "Your cache folder contains root-owned files, due to a bug in previous versions of npm" while "npx create-react-app example_app"
When I was trying to create a new react app using npx create-react-app example_app, I get this error
[Your cache folder contains root-owned files, due to a bug in previous
versions of npm which ...
user6795343
55
votes
8
answers
30k
views
How to make create-react-app use npm instead of yarn?
I kind of rushed into creating a React app based on a tutorial that used yarn. Now I'm going to re-create the app from scratch because I'm not satisfied with the reactstrap library, and I'd like to ...
- 36.3k
54
votes
29
answers
259k
views
I can't install React using 'npx create-react-app'
I am trying to use the npx create-react app, but I have errors that are shown below:
npm ERR! Unexpected end of Json input while parsing near
'...eact-app/-/create-rea'
npm ERR! A complete log of ...
- 559
53
votes
4
answers
24k
views
How to avoid React loading twice with Webpack when developing
Given the following directory structure:
my-project
|
|-- node_modules
|
|-- react
|-- module-x
|
|--node_modules
|
|--react
You can see both my-...
- 5,038
53
votes
3
answers
43k
views
What is the correct way of adding `react` as a dependency in the `package.json` of a reusable components library?
I built a few reusable React components, and I want to know the correct way to add react as a dependency in my package.json for the purpose of publishing to the npm registry.
I am currently doing this:...
- 23.9k
53
votes
2
answers
123k
views
What is "npm run build" in create-react-app?
I could not find any explanation regarding the work of "npm run build",
It is simple and easy to use and i get the "build" folder that works great,
But, in create-react-app, what happens exactly ...
- 593
53
votes
7
answers
71k
views
webpack warning - WARNING in DefinePlugin Conflicting values for 'process.env.NODE_ENV'
I'm getting the warning in the title when I try to run development mode. This script used to work fine for an earlier website but now I always get this warning.
This is my package.json:
{
"name&...
- 767
51
votes
10
answers
26k
views
How to avoid `loaded two copies of React` error when developing an external component?
I am developing an external component (let's say my-component, which I link to the project with npm link (as it is in process and I need the package to reflect changes).
In the my-component folder ...
- 3,569
50
votes
16
answers
83k
views
How to use materialize-css with React?
I have a Meteor/React project, using ES6 modules. I've installed materialize-css using npm, but I'm not sure how to actually use the Materialize classes in my JSX code. What am I supposed to import ...
- 27.2k
50
votes
8
answers
43k
views
Package that is linked with npm link doesn't update
I have two modules - my main project and a component library - where I want to link the lib to the main project. Both is working with webpack and react. So I did:
In comp-lib dir:
npm link
In ...
- 986
49
votes
7
answers
58k
views
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
Note: Due to security concerns, please don't use the marked solution but instead the highest voted one!
original question:
I am trying to install monaca with this command.
npm install -g monaca
But ...
user10378098
49
votes
7
answers
77k
views
How to inject API server URL when deploying react frontend?
Disclaimer: I am a React noob so perhaps what I am trying to do is not the React Way
I am writing a React front-end that will be deployed to be served statically by some cloud provider, e.g. S3 or ...
- 4,648