I learned about Yarn and wanted to try it with React so I installed Yarn, and now when I run create-react-app hello, one of the scripts appear to be yarn add v0.24.6, which installs 879 dependencies into my node_modules directory.
Why is this happening and how do I make it stop? Or do I just not understand Yarn and this is supposed to be something I want?
Were you using npm2 before? With it, you'd only see your app's direct dependencies in node_modules and their dependencies (i.e. your app's transitive dependencies) would be tucked away in nested node_modules dirs.
Yarn and npm >= 3 flatten dependencies in node_modules, so you're seeing all of react-scripts' direct dependencies and all of its transitive dependencies.
Every package we use might depends on others packages.
yarn and npm > 3 use flat structure for resolving dependencies of other packages dependencies. So, your node_modules folder container long list of folders.
npm < 3 use nested tree structure. So, your node_modules folder container few list of folders and dependencies of other packages nested inside package/node_modules folders.
so, why use npm > 3 or yarn?
Those are fast for resolving dependencies. I hope you have not yet experience on waiting for 1hours or more after npm install :D.
why yarn over npm?
There are lots of articles written on this topic. Just google it.
Related
I am seeing a weird behaviour with package-lock.json. Once I remove node_modules and package-lock.json and then build them, my application works as expected. When I do a npm install again with just built package-lock.json existing, the file entirely changes removing lot of packages from the tree. When I run the server now, certain Modal (from react-bootstrap ) components don't work properly. I don't understand why this file should change and end up installing different version of dependencies which is breaking the code. Am I doing something wrong with regards to package-lock.json?
Every time I remove both node_modules and this file and build I don't face any issue. Only when this file is already present and I do npm install I run into issues.
npm install creates a new package-lock.json whenever you update node_modules i.e when you install a new module/package. So the overriding of the pre-existing package-lock.json is expected behavior.
As for the Modal breaking it is likely because of version conflict. If you post the 'break' error we could better determine what's causing it but this usually happens when you're packages require a certain version of another dependency.
A possible solution would be to delete node_modules and the original package-lock.json file and then run install. You can also try npm ci.
EDIT
This link might be helpful in giving you more insight into package-lock.json files and how they are affected by npm install. Essentially, once lock file has been generated, it avoids updating to newer versions - until you edit package.json to specify a different version or range. Whatever you're trying to install you should do it from the command line.
npm install changes the packages.json and package-lock.json because it tries to install newer versions of dependencies.
If you don't want this and wish to leverage package-lock.json and leave packages.json as is, try npm ci.
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 thing that works is the SKIP_PREFLIGHT_CHECK=true in my .env as the last resort for both
Yarn and npm. I have recently updated to Mojave and had to reinstall my Xcode if people have had a similar experience.
Last login: Tue Oct 30 16:30:24 on ttys002
TheLAB11:~ jasonspiller$ cd repos/react-express-graphql-app/
TheLAB11:react-express-graphql-app jasonspiller$ npm start
> react-express-graphql-app#0.1.0 start /Users/jasonspiller/repos/react-express-graphql-app
> react-scripts start
There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.
The react-scripts package provided by Create React App requires a dependency:
"babel-jest": "23.6.0"
Don't try to install it manually: your package manager does it automatically.
However, a different version of babel-jest was detected higher up in the tree:
/Users/jasonspiller/node_modules/babel-jest (version: 23.4.2)
Manually installing incompatible versions is known to cause hard-to-debug issues.
If prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.
To fix the dependency tree, try following the steps below in the exact order:
1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
2. Delete node_modules in your project folder.
3. Remove "babel-jest" from dependencies and/or devDependencies in the package.json file in your project folder.
4. Run npm install or yarn, depending on the package manager you use.
In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:
5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
This may help because npm has known issues with package hoisting which may get resolved in future versions.
6. Check if /Users/jasonspiller/node_modules/babel-jest is outside your project directory.
For example, you might have accidentally installed something in your home folder.
7. Try running npm ls babel-jest in your project folder.
This will tell you which other package (apart from the expected react-scripts) installed babel-jest.
If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That would permanently disable this preflight check in case you want to proceed anyway.
P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! react-express-graphql-app#0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the react-express-graphql-app#0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/jasonspiller/.npm/_logs/2018-10-30T23_09_42_358Z-debug.log
I just had the same problem. For some reason the package ended up in a node_modules directory in my home directory. It also gave me the exact same error for the jest package.
I'm not sure of the correct way to fix this as npm uninstall -g babel-jest and yarn global remove babel-jest do not do anything.
I fixed it by just blowing away the folders that cause the problem:
bash
rm -rf ~/node_modules/babel-jest ~/node_modules/jest
It would be great to know how those packages ended up there, and the proper way of getting rid of them, but for now just deleting the folders is enough to get CRA dev server running without skipping the preflight check.
This problem can occur if there is node_modules in a parent directory of the folder where you run the application. I solved the problem by deleting the node_modules directory.
I too faced a similar problem and was able to resolve the issue following below steps.
Create a .env file in your project root directory and add the following statement
SKIP_PREFLIGHT_CHECK=true
Save the file
Remove node_modules, yarn.lock, package.lock
Then reinstall node_modules with
npm install
This should work
The problem seems to have reappeared in create-react-app 3.0.0.
The react-scripts package provided by Create React App requires a dependency:
"babel-jest": "24.7.1"
As abisuq pointed out in https://github.com/facebook/create-react-app/issues/6756#issuecomment-489562571 adding a version resolutions into package.json temporarily fixes the problem.
"resolutions": {
"babel-jest": "24.7.1"
},
Update: It has been fixed in create-react-app 3.0.1. If upgrading is an option you can run
npm install --save --save-exact react-scripts#3.0.1
or
yarn add --exact react-scripts#3.0.1
run： npm ls babel-jest
got : babelk-jest#24.7.1 & babel-jest#24.8.0 installed
this means install tow babel-jest with diff version
run：npm uninstall babel-jest#24.8.0 fix my issue
I had this issue and finally solved it easily.
As probably you know, when we use create-react-app, Jest is configured by default and you don't need to install Jest (when we use Webpack, we can install Jest). So, if you use Create-react-app and install Jest by mistake:
Firstly uninstall it (remember that if you use: (npm install --save-dev jest), you can remove jest directly from Package.json or use: (npm uninstall --save-dev jest)
Delete package-lock.json (not package.json)
Delete the node_modules
npm install
Now you don't receive an error and you can easily use: (npm start) or (npm test)
Also, It is worth mentioning that I installed the following tools to write my test in React component:
(npm install --save-dev enzyme enzyme-adapter-react-16 jest-enzyme)
and wrote my test by using jest and enzyme. Then I easily use: (npm test)
Good Luck!
Ok I finally found a solution after trying everything. Here is what finally worked:
First of all, read the error message in the cmd from the beginning. They'll tell you what module is causing the problem. You probably have an older version installed on your computer. Example: babel-jest version 2.4.4
Go to your Node.js folder c:/Users/(your user)/node_modules and find that module and simply delete it.
Go back to the cmd and run npm start. You might get the same error. But it'll be for a different module. Just delete it the same way and repeat until it runs.
I fixed the issue by removing the node_modules folder and package-lock.json file from a folder that was higher than the root of the project. I had installed node_modules accidentally in a higher folder.
I had:
desktop/code/node_modules (remove this to fix)
desktop/code/package-lock.json (remove this to fix)
desktop/code/project/node_modules
desktop/code/project/package-lock.json
I was having this issue as well. When I tried to run the client using npm start, the error would occur, telling me that it required babel-jest: ^24.9.0.
I noticed that in my client, babel-jest was version ^24.9.0, but in my server, I had "jest": "^26.6.3".
All I had to do was change "jest": "^26.6.3" to "jest": "^24.9.0" in the server side source code, delete my package-lock.json as well as node_modules in server, npm install again, and good to go!
At first I installed these (my react version was "^17.0.2")
npm install --save-dev jest
npm install --save-dev enzyme enzyme-to-json
npm install #wojtekmaj/enzyme-adapter-react-17
After that, I had the same problem.
Then I did these steps :)
Added '.env' file in my project root directory and add:
SKIP_PREFLIGHT_CHECK=true
Removed node_modules & package.lock
npm install
npm start
I had the exact same issue.
What I tried was to create the react app outside the directory that had the node_modules folder.
After that, started the app with yarn start and didn't have the error anymore.
I had the same problem, and I fixed this issue. For some reason because node_modules on my local. I removed babel-jest & jest. After that, npm start. I'm not sure this solved incorrect but this correct for me.
I solved this issue by deleting the node_modules folder and package-lock.json file I accidentally had installed in the root of my user.
For me in Mac the path was:
Macintosh HD -> Users -> "My-user-name"
I discover that might be the problem by running npm ls babel-jest on terminal. That showed me that there was another babel-jest up in the tree.
After deleting these two I did npm install in my app where I previously had deleted the node_modules folder and package-lock.json.
Now it's running ok !
I fixed this by deleting node_module folder in the project directory
try this command and see which packages create conflicts in versions.
npm ls babel-jest
replace the conflicted packages with updated one of that package.
I tried all of written solutions above. But none of them worked. I solved problem by deleting "C:\node_modules" folder.
Then delete project node_modules and package-lock.json. Finally, npm install and start again. And it worked.
My react-scripts version is 4.0.3. The problem suddenly happened after installing a private remote package, which installed multiple babel packages in my project root's node_modules. I solved this by installing the problematic packages on the project root's level explicitly, so that they match the versions reported in the preflight check.
Following addings fixed it in my case. Your needed packages and versions may differ, you have to check the preflight report.
yarn add babel-jest#^26.6.0
yarn add babel-loader#8.1.0
For me its still a workaround, but i prefer this way instead of removing something in node_modules manually as suggested in https://stackoverflow.com/a/53093421/4840661.
This is the approach without deleting node_modules:
I recieved error like:
The react-scripts package provided by Create React App requires a dependency:
"jest": "26.6.0"
Don't try to install it manually: your package manager does it automatically.
However, a different version of jest was detected higher up in the tree:
First check the versions using:
npm ls babel-jest
In my case output was like this:
jest#27.0.3
└─┬ #jest/core#27.0.3
└─┬ jest-config#27.0.3
└── babel-jest#27.0.2
After that uninstall babel-jest by
npm uninstall babel-jest
(When you see the single version of babel-jest,otherwise go as versions as follows)
npm uninstall babel-jest#27.0.2
Then install required dependencies using
npm i babel-jest#version jest#version
(Where version is the one come in 1st point)
This works for me like a charm. Hope this solves you too.
Got this error in the netlify ci, here's the fix that worked for me:
this method works for any lib i got a error for eslint instead of babel-jest.
force the error to be shown by npm i -s #babel-jest/VERSION --force
replace VERSION with whatever version shows in the error(23.6.0 in this case),
the correct error message will be shown locally
use https://www.npmjs.com/package/npm-check-updates to upgrade your package.json flie with the correct versions
run ncu -u in dir of package.json after installing the npm package
globally
finally do a npm ci
this will delete the package-lock and node_modules and install the new versions based on the second step
this work for me.
clear caches in npm or yarn
remove node_modules and lock files
create .env file
add " SKIP_PREFLIGHT_CHECK=true " to an .env file in your project.
my issue was that I have both frontend and backend that I am running concurrently. I installed jest to my root project (for backend) and I guess there is collision with pre-installed react jest. I just uninstalled jest from backend and voila I am happy now. I don't have anything related with babel.
i had the similar problem and wasted my 2-3 days
The easiest way to solve this problem is :
1.go outside of src, and create .env file.
2.Inside .env file, just write this single line and save it:
SKIP_PREFLIGHT_CHECK=true
3.then npm start
Hope this helps, Happy coding!!!
There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.
The react-scripts package provided by Create React App requires a dependency:
"eslint": "5.6.0"
Don't try to install it manually: your package manager does it automatically.
However, a different version of eslint was detected higher up in the tree:
D:\chintu\blog-exambunker-master\blog-exambunker-master\node_modules\eslint (version: 5.6.1)
how to install the version 5.6.0 I am installing the eslint it always gets installed with the latest version, can someone suggest me what to do?
The error is an incompatibility between eslint and babel-eslint versions. To do solve this, firstly you need to remove your eslint package using npm uninstall eslint. This command will delete your eslint package. After this, you need to install the 5.6.0 version of eslint, so write this command npm i eslint#5.6.0. I hope that this will be helpful for you. Also, you can delete your node_modules folder and then install it.
(Do not do what I did if you don't read everthing I posted) At least with me, I just downgraded my eslint 5.8.0 to 5.6.0 (manually). Why? Because when I use some eslint library like airbnb, it installs the latest version of eslint (5.8.0) automatically, the problem here is that this version has conflict with the previous eslint version used by react (5.6.0), so when you downgrade, you just return to the previous eslint installed, so it's working fine here, but you've to be careful when you update your react version.
I searched where the eslint was with:
npm ls eslint
then I deleted it with:
npm uninstall ls eslint
Finally I ran
npm start
and it worked.
Create a file .env in your root directory.
And you can ignore the check by putting
SKIP_PREFLIGHT_CHECK=true
in .env file.
Ref: https://github.com/facebook/create-react-app/issues/5247#issuecomment-427221678
Edit: This is not the solution to this problem. It is just to ignore the error as it is discussed in the issue.
I have the exactly same problem. I have tried everithing from those Suggestions:
Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
Delete node_modules in your project folder.
Remove eslint from dependencies and/or devDependencies in the package.json file in your project folder.
Run npm install or yarn, depending on the package manager you use.
In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:
If you used npm, install yarn and repeat the above steps with it instead.
This may help because npm has known issues with package hoisting which may get resolved in future versions.
Check if C:\Users\User\node_modules\eslint is outside your project directory.
For example, you might have accidentally installed something in your home folder.
Try running npm ls eslint in your project folder.
This will tell you which other package (apart from the expected react-scripts) installed eslint.
nothing worked. every time I am doing npm install/yarn it keeps install the old version of eslint.
ok I find my issue: I had npm packeges and some more crap outside the projects folders (on c:/users/user) they may had the old version of eslint. cheack it out and tell me if you still have the problem or not.
I deleted a node modules folder that contained an older version of eslint. I found this to be the easiest solution rather than changing dependencies.
What solved this for me, was that in the error message, it told me that there was eslint installed in project with 5.6.0 and another installed in users/andrew/nodemodules/eslint with a version of 4.1.6 I tried doing a npm uninstall -g eslint but that didnt work so then I just searched for all the files and folders within users/andrew/nodemodules/eslint
and deleted them, and it worked for then.
I'm not sure if this is a good way to do it, but its worked.
Simple delete package-lock.json and node_modules then run npm install then
npm start
else you could install
npm i eslint#5.6.0 then
npm start
enjoy your work :)
List item
Open a NEW terminal window within root.
Run the command
npm ls eslint
this should show you the installations that are 'higher' up the dependency tree.
Navigate into the folder(s) that contain gulp-eslint/eslint/babel-eslint or even a sneaky node_modules/ that shouldn't have been installed globally.
Next, run either or all of these commands depending on where the files are situated.
rm -rf node_modules/
rm -rf (name of other folders like eslint/gulp-eslint)
RETURN TO YOUR PROJECT
Better to be safe than sorry, run the following commands to make sure it will work properly again.
Within the root directory of your project
rm -rf node_modules/
rm -rf package-lock.json
(If it didn't remove the node_modules just delete it from your folder)
Finally, Run the following.
npm install
then
npm start
go to node_modules folder and open react-scripts/package.json , find the eslint dependencies and change it. its fixed this way.
https://github.com/wesbos/eslint-config-wesbos/issues/17
In the above mentioned link they suggested to install #abhijithvijayan/eslint-config as peer dependency. See if this works for you.
you might install a global eslint like this
{22:14}~/go/src/github.com ➭ npm ls eslint
/Users/demon
└── eslint#6.1.0
then run
{22:14}~/go/src/github.com ➭ npm uninstall eslint
in the global terminal instead of vscode's terminal. then run
npm start
I just used this command: "npm uninstall eslint". Later I just ran mu=y code using npm run start and it worked. I did not have to delete or edit any file
Add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.
The react-scripts package provided by Create React App requires a dependency:
"eslint": "5.6.0"
Don't try to install it manually: your package manager does it automatically.
However, a different version of eslint was detected higher up in the tree:
/Users/macbook/node_modules/eslint (version: 3.19.0)
Manually installing incompatible versions is known to cause hard-to-debug issues.
If prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.
To fix the dependency tree, try following the steps below in the exact order:
Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
Delete node_modules in your project folder.
Remove "eslint" from dependencies and/or devDependencies in the package.json file in your project folder.
Run npm install or yarn, depending on the package manager you use.
In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:
If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
This may help because npm has known issues with package hoisting which may get resolved in future versions.
Check if /Users/macbook/node_modules/eslint is outside your project directory.
For example, you might have accidentally installed something in your home folder.
Try running npm ls eslint in your project folder.
This will tell you which other package (apart from the expected react-scripts) installed eslint.
If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That would permanently disable this preflight check in case you want to proceed anyway.
P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! my-app#0.1.0 start: react-scripts start
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the my-app#0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/macbook/.npm/_logs/2018-11-01T15_26_42_405Z-debug.log
Why is it necessary to run 'npm install' when I already have all the dependence in node_module folder.
After running 'npm install' successfully on my machine, I want to setup same project on another machine, why do I require run 'npm install' again when I already have downloaded all the dependence in node_module folder?
First of all I want to inform you 2 things:
As your project depend on some packages (node_modules), same as some packages are dependent on other packages.
when we install some package with command npm install package -g then -g will install it in global folder which can be accessed by any project. by using -g, package is not added to node_modules.
Now here is answer of your problem. There might be possible that some dependencies of packages are installed as global on one machine and not on other one. This can happen as developers work on many project on same machine and might be they have installed global packages. So in this case you need to execute npm install command.
npm install extract all your dependencies from your package.json, download it and save them in your node_modules folder. You don't need to run npm install again and again if you already have installed all your dependencies locally.
When ever you installs a new dependency you run npm install <package-name> --save and why --save for the first time? because it adds the new installed dependency on your package.json. We never push node_modules to our git repo only the updated package.json is pushed to repo. In that case if a new person pulls your code from the repo he is only going to run npm install and all the dependencies mentioned on your package.json will going to available on his project locally. Thats a small intro about why we use package.json hope it helps.
Check the version of node in both system .
I guess that would be issue. you local system would have either higher version than the server. May be not able to compile for higher version make sure the version are same for node in both , to reduce the comflict.
This question already has answers here:
Difference between Grunt, NPM, and Bower (package.json vs bower.json)
(2 answers)
Closed 5 years ago.
What is the difference between package.json vs bower.json.?
what is the criteria that we should consider before defining the dependencies in both files.
And what difference will it make by running "bower install" and "npm install" ?
NPM (package.json)
npm is most commonly used for managing Node.js modules, but it works for the front-end too when combined with Browserify and/or $ npm dedupe.
Bower (bower.json)
Bower is created solely for the front-end and is optimized with that in mind. The biggest difference is that npm does nested dependency tree (size heavy) while Bower requires a flat dependency tree (puts the burden of dependency resolution on the user).
A nested dependency tree means that your dependencies can have their own dependencies which can have their own, and so on. This is really great on the server where you don't have to care much about space and latency. It lets you not have to care about dependency conflicts as all your dependencies use e.g. their own version of Underscore. This obviously doesn't work that well on the front-end. Imagine a site having to download three copies of jQuery.
In short, NPM aims for stability. Bower aims for minimal resource load. If you draw out the dependency structure.
npm dependencies are defined or added to package.json. Bower dependencies are in bower.json.
** Package.json file is for node related package manager while bower can manage application level package dependencies. I like bower more.
** We need to find which dependencies related to development and which are production.
** "bower install" -- Install all dependencies mentioned in Dependencies object.
** "bower install -D" -- Install all dependencies mentioned in DevDependencies object.
Same with Npm Install and npm install -D