How to debug local NPM dependency (using `npm link`) with source-maps? - javascript

I am using babel-cli to compile my local NPM dependency source code.
package.json:
"main": "lib/index.js",
"scripts": {
"dev": "babel src --watch -d lib --source-maps inline",
},
The local NPM dependency was referenced by my other application. Now I need npm link to debug local NPM dependency. How can I debug with source-maps?

You may try source-map-loader with webpack
https://github.com/webpack-contrib/source-map-loader

Related

not working "NODE_ENV=development nodemon server.js" commnd in window and showing error as below mention

NODE_ENV=development : The term 'NODE_ENV=development' is not recognized as the name of a cmdlet, function, script file, or operable program. Check
the spelling of the name, or if a path was included, verify that the path is correct and try again.
Need win-node-env module
npm install -g win-node-env
For Windows
SET NODE_ENV=development
node app.js
For setting environment variables like that on Windows you can use package called cross-env.
You can install it by: npm install --save-dev cross-env. And then you have almost exact example from their docs:
{
"scripts": {
"build": "cross-env NODE_ENV=production webpack --config build/webpack.config.js"
}
}

Apply changes from linked npm modules without rebuilding

My webapp consists of two modules from separate git repos, with the following directory structure:
webapp/module1
webapp/module2
module1 depends on module2, so I've added the link:
cd webapp/module1
npm link ../module2
The module1 is main module, so I'm running webapp using npm start from there:
cd webapp/module1
npm start
start is configured in module1's package.json as follows:
{
"scripts": {
...
"start": "webpack-dev-server --open --progress --colors & npm run build:css -- -w",
"build:css": "node-sass src/style/main.scss dist/webpage.min.css --output-style compressed"
}
}
The problem is when I make a change to module2 source code editing its javascript sources - the change is not applied immediately to the running webapp instance. I need to execute npm run build manually:
cd webapp/module2
npm run build
build is configured in module2's package.json as follows:
"build": "cross-env WEBPACK_ENV=prod && npm run v:patch && webpack"
Only after this step the changes are applied to the webapp. Is there a way to get such changes to be applied automatically? I'm using npm version 5.6.0.

How to have different .env file for Grunt for staging/production?

How can I have a different .env file in my project when compiling my project with Grunt?
npm install --save cross-env
In your package.json
"scripts": {
"start": "cross-env PROJECT_ENV=production grunt",
"dev": "cross-env PROJECT_ENV=development grunt"
}
In your grunt file you can use process.env.PROJECT_ENV to verify the current environment depending on which script you run.

Using babel-cli locally

Is there a way to use the babel client without installing it globally?
So rather than this
npm install -g babel-cli
I'd like to do this
npm install babel-cli --save-dev
Any local package's binary can be accessed inside npm scripts as if it was installed globally:
// package.json
{
"scripts": {
"build": "babel ..."
}
}
If you want to execute the binary on the command line, you can use a relative path to node_modules/.bin/:
$ node_modules/.bin/babel ...
This is related to first example: node_modules/.bin/ is simple added to the PATH of the environment the npm scripts are executed in.
you can put something like this:
{
"scripts": {
"start": "babel-node test.js"
}
}
in your package.json where test.js is a script which you want to run. Now you can run it with npm start command
Yes, you could install locally and run from node_modules:
./node_modules/.bin/babel
If you have a local package.json you could add an NPM script to simplify the command, since NPM scripts run with ./node_modules/.bin on the PATH:
"scripts": {
"babel": "babel ...",
}
To run from any directory under package.json:
$ npm run babel
If you just want to run test with command "npm test testFile.js". This is my package.json:
"scripts": {
"build": "babel-node",
"test": "node_modules/.bin/babel-node"
}

How to use nodemon with .env files?

I am using an .env file to hold environment variables for the server. This works if I run the server with foreman start. But it doesn't work with nodemon.
I would like to use nodemon instead because it restarts automatically when you modify the server. How can I get nodemon to work with .env files?
Install dotenv npm i dotenv
Create .env file and your variables inside
Add the script to execute
"dev": "nodemon -r dotenv/config ./app/index.js " or
"start": "node -r dotenv/config ./app/index.js "
Run the app using npm run dev or npm run start
I have a production Procfile with:
web: node web.js
So I have created a Procfile_dev file with:
web: nodemon web.js
And when I am at development environment I run:
$ foreman start -f Procfile_dev
It works like a charm and doesn't affect production.
You can get nodemon to directly use the .env with the following command
$: env $(cat .env) nodemon app.js
Be aware that you'll have to restart it if you make changes to .env and it won't like it if there are any spaces in your .env file.
With recent versions of Node (since io.js 1.6), you can pass it the -r flag to require a module on start. This lets you directly load .env by using nodemon's --exec:
nodemon --exec 'node -r dotenv/config'
This requires the npm package dotenv to be installed.
Place your local configuration variables in the .env file and run foreman along with nodemon using the following command
$ foreman run nodemon web.js
This works pretty well for me so far,
nodemon -w . -w .env index.js
How it works:
"-w ." tells nodemon to watch the files in the current directory
"-w .env" tells nodemon to watch the .env file
"index.js" is just the file to run when changes occur (could be anything)
"scripts": {
"start": "node -r dotenv/config src/server.js dotenv_config_path=dev.env dotenv_config_debug=true",
"start:dev": "nodemon --exec \"npm start\""
}
In my case the .env file is used for development and not deployment. So I wanted my code to be decoupled from the .env file. Ideally I didn't want to import 'dotenv/config' anywhere in my code. This is my solution:
My nodemon config:
{
"watch": [
"src",
".env"
],
"ext": ".ts",
"exec": "ts-node -r dotenv/config ./src/index.ts"
}
My NPM script:
"start:dev": "nodemon"
In this solution ts-node requires dotenv, which sets up the environment variables before the main app starts. This means that nowhere in my code do I need a import 'dotenv/config'. dotenv can become a dev dependency, and this also prevents dotenv to be loaded at all once the code is deployed.
Thread necromancy!
Use grunt-env to load environmental variables from your heroku config.
In Three steps
Creating the file on root folder > .env
# .env ======
PORT=5000
WHO_AM_I="Who Knows"
Install the dotenv
Run below command
"dev": "nodemon -r dotenv/config src/app.js"
You can access the your defined variables using > process.env.varible_name
If you want to run Typescript in nodemon and require a particular .env file with dotenv then you can do:
In package.json scripts:
"dev": "nodemon -r dotenv/config src/myApp.ts dotenv_config_path=/path/to/your/env/file",
And a line in nodemon.json to tell nodemon to use ts-node when encountering Typescript extensions:
"execMap": {"ts": "node -r ts-node/register"},
This is useful for using a development .env file say .env.development.local for local dev work and leave the main .env file for live production variables.
Use the -w key to specify nodemon what to watch additionally.
"scripts": {
"dev": "env-cmd nodemon -w app -w *.js -w .env server.js"
}
Don't forget rerun npm run dev
Heroku Procfile
Change: web: node app.js to web: nodemon app.js
To load the dotenv package and any declared .env vars into the environment, you can do the following:
nodemon -r dotenv/config myapp.js
I use cross-env for environments.
npm i cross-env
set package.json.
"start": "cross-env NODE_ENV=production node dist/app.js",
"dev": "cross-env NODE_ENV=dev nodemon --exec ts-node src/app.ts",
npm run start OR npm run dev

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