Getting error while running npm start after installing react JS - node.js

Error while running npm start.Getting this error while running npm start command

This problem can occur from 3 things:
You don't have a start script in your package.json
Your project does not contain a server.js file
You added a second script key in the package.json file

If you want to use ' npm start ' to run your code, your packaje.json file must contain start script. Something like this.
"scripts": {
"start": "node app"
}

Related

How to make a node.js server run with a specific command

I want to start my index.js file with node --max-old-space-size=1024 index.js but I don't want to type the command manually everytime, any Idea how can I make a .js file that executes the command for me? Like start.js and when I launch it, it immediately runs node --max-old-space-size=1024 index.js. This might be super straight forward but I'm still new to node.js 😅
You can modify your package.json to create a command that execute node --max-old-space-size=1024 index.js
In your package.json
"scripts": {
"start": "node --max-old-space-size=1024 index.js"
}
And then run npm run start.

how does cross-env command works in nodejs?

I have the following line in my package.json
"scripts": {
"start": "cross-env NODE_ENV=development node index.js"
}
I can see that "yarn start" command is running fine, but when I run
"cross-env NODE_ENV=development node index.js" command directly in the terminal, I am getting the following error:
zsh: command not found: cross-env
If cross-env is not registered in the terminal, how does "yarn start" command works?
https://docs.npmjs.com/cli/v7/configuring-npm/folders#executables
When in local mode, executables are linked into ./node_modules/.bin so that they can be made available to scripts run through npm. (For example, so that a test runner will be in the path when you run npm test.)
It's simply a feature to make things easier. It also means if you're working a project with multiple people, you only have to npm install --save a module--you don't have to worry about everyone in your project manually installing it globally. If you wish to run it yourself on the command line, you can either:
Install the module globally
Manually type in the command line ./node_modules/.bin/cross-env

How to call Terminal Commands in a TEXT File?

I really need help on this, couldn't find much examples on google.
For example:
I have this web project. Inside this project there is, app.js, views/home.ejs, some npm packages and etc...
This project, we are not allowed to type "npm install" "npm start" to run our project or we get a zero. The teacher will only type 1 line in terminal which is "run app.py" for python or "run js app" to run our code, will not install packages on localhost.
Wants us to make a textfile to automatically install all packages in the background and run the application automatically? How would I do that?
For example in text file:
inside TXT.FILE {
#1 run "npm install express" in terminal
#2 run "npm install body-parser" in terminal
#3 run "node app.js" in terminal
#4 also run "ls"
}
Basically just call terminal commands in a text file. A text file that will automatically execute them in order.
You have two options.
Add this into your package.json file
...
"scripts": {
...
"start": "npm install express && npm install body-parser && node app.js && ls"
},
Now you can use npm start to run all these commands at one go.
Add a bash script in your project directory.
The file should be named your-script-name.sh.
Inside add
#!/bin/bash
npm install express && npm install body-parser && node app.js && ls
You can run the script using ./your-script-name.sh in your terminal.
"scripts": {
...
"start": "npm install express && npm install body-parser && node app.js && ls"
},
Yes this works very well, tested it! Thank you.
This calls terminal commands under 1 line of code!

How can I solve this errorv - npm start - npm ERR! missing script: start

I am receiving this error when I tried to write npm start command after installing the react.
Check your package.json file. It should contain the start entry in the scripts key.
Read the npm docs for detailed information.
Your package.json should contain this entry:
"scripts": {
"start": "node main.js"
}
Replace main.js with the script name you are trying to run. You can test its execution by just running node main.js in the console and determining whether that even works.

How does "npm" run "npm test"?

I always thought that npm test command just launches what I would write in package.json inside scripts: { test: ...} section. But I have this weird bug when it doesn't work.
So, I have this piece of config in package.json
"scripts": {
"start": "node index.js",
"test": "mocha tests/spec.js"
}
When I try to run tests I type npm test in terminal and had this error:
module.js:340
throw err;
^
Error: Cannot find module 'commander'
But everything is OK when I type just mocha tests/spec.js. Any ideas why is that?
UPDATE:
I've tried to install commander and I had an error Cannot find module 'glob'. After installing glob I have
Error: Cannot find module '../'**
But actually question is why do I have these errors and why is everything OK when running mocha tests/spec.js?
You may have two versions of mocha installed: one globally (npm install -g mocha) and one locally, which appears to be broken.
When you run a script through npm, either as npm run-script <name> or with a defined shortcut like npm test or npm start, your current package directory's bin directory is placed at the front of your path. For your package that's probably ./node_modules/.bin/, which contains a link to your package's mocha executable script.
You can probably fix this by removing the local mocha and reinstalling it with --save-dev:
rm -rf node_modules/mocha
npm install --save-dev mocha
That should get you a working local copy of mocha with all its dependencies (commander etc.) installed.

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