I am running the node js application. In package.json I am building the file like below and running with the start command from package.json.
"scripts": {
"build:server": "npx babel server --out-dir dist/server",
"start": "node ./dist/server/app.js",
"build:client": "webpack"
}
When I execute the build command, the changes were available in the dist folder. But I run the start command I am not able to see my changes on executing my Rest API call.
I am building an app using nodejs and express framework and have installed nodemon globally to restart the server automatically.
Now if I take this app and run in another machine/host/environment (without nodemon installed globally) then it would produce an error because package.json doesn't contain nodemon as a dependency.
What would be the best way to fix this?
Include nodemon in your package.json as a dev dependency. So it will be available in the context of the script.
{
"scripts": {
"start": "nodemon my_file.js"
},
"devDependencies": {
"nodemon": "<version>",
}
}
Then from the terminal you can use npm start
Nodemon has been the goto for a long time, but now with Node.js 19, we have --watch flag, which restarts server when files changes. Keep in mind this is experimental
Docs
:)
So I have a series of scripts that are set up to either dev servers for a React/Node Express application OR a production server on heroku. The structure of the app is as follows:
client/package.json //pckg for react app
package.json //pckg for the node server
these are the scripts in the clients package:
"scripts": {
"start": "if-env NODE_ENV=production && npm run start:prod || npm run start:dev",
"start:prod": "node server.js",
"start:dev": "set NODE_ENV=development&& concurrently \"nodemon --ignore 'client/*'\" \"npm run client\"",
"client": "cd client && npm run start",
"seed": "node scripts/seedDB.js",
"install": "cd client && npm install",
"build": "cd client && npm run build",
"heroku-postbuild": "npm run build"
}
and the only difference between the react apps package.json and the one that is automatically generated with create-react-app is as follows:
"proxy": "http://localhost:3001/",
the way its supposed to run is, install scripts at root folder, run install script to cd into client and install react apps dependencies, then heroku's post-build script should kick in to run the build script which cds into client and builds a production ready react app. finally the start script should see a NODE_ENV of production and run start:prod.
my problem is that for some reason when i push to heroku, it seems to get stuck on an infinite loop on the install script. I have NO clue why, as the exact same scripts work on other projects PERFECTLY.
https://github.com/LordKriegan/reactdbdemo
https://github.com/LordKriegan/reactdbdemo2/ if anyone wants to look at it. (doing a full stack demo for my students :/ not much of a demo if i cant get it deployed)
I got it working. Forgot create-react-app also initializes a git repo...? either that or somewhere along the way i did an extra git init. anyways i had a .git folder in my client folder, which was preventing my client folder from being pushed up. i ended up creating a new repo and pushing everything to that one and now it works. so incase anyone comes here with a similar problem... make sure you didnt end up in some kind of gitception trap. :/
brothers and sisters, I am trying to do this:
"scripts": {
"start": "node ./node_modules/.bin/http-server ./public",
"poststart": "webpack --watch"
}
It is not working. The idea being node runs the app (duh) and there's a webpack --watch instance rebuilding my code as it changes. What's the answer here?
One way to do it is like this:
you start webpack --watch in one terminal to watch the sources and rebuild when changes occur
you use nodemon (which is a npm package) in another terminal to watch for build (NOT source) changes and restart the app
Reference: https://nodemon.io/
When testing locally I was previously running:
"build-live": "nodemon --exec ./node_modules/.bin/ts-node -r dotenv/config -- ./index.ts"
I then figured my Procfile should be something like:
web: ./node_modules/.bin/ts-node -- ./index.ts
But it says module 'typescript' not found, even when it is in package.json. I read in a few places that ts-node is not the way to go to deploy to Heroku, so I am not sure what to do.
UPDATE: I think I am supposed to compile it, so I tried:
web: ./node_modules/.bin/tsc --module commonjs --allowJs --outDir build/ --sourceMap --target es6 index.ts && node build/index.js
This succeeds, however when actually running it, a bunch of the libs I'm using get "Cannot find module '...'".
Alternatively you can have the TypeScript compile as a postinstall hook and run node build/index.js as the only Procfile command:
Your package.json should contain a postinstall hint that gets executed after npm install and before the node process launches:
"scripts": {
"start": "node build/index.js",
"build": "tsc",
"postinstall": "npm run build"
}
You can then leave your Procfile as is:
web: npm start
This 'build on deploy' approach is documented by Heroku here.
The command you've given Heroku is to launch the web "process" by compiling index.ts and dependencies and starting node at index.js. Depending on how things are timed, index.js might or might not exist at the time node starts.
You need to already have your sources compiled by the time you want to start your app. For example, web should just be web: node index.js or similar.
Each build process is different, so you need to figure that out for your own setup. But, suppose you have a classical setup where you push to git and then Heroku picks up that change and updates the app with the new slug. You could just compile things locally and include index.js and any other build output in the repository, for it to be available in the slug for Heroku to use.
A better approach is to use a build server which has an integration with Heroku. After you do the build there, configure it to send the build results to Heroku. Travis has a straighforward setup like this. This way you don't need to include build outputs in your repository, which is considered an anti-pattern.
On a sidenode, try using a tsconfig.json to keep the tsc configuration. It will save you from having to write such long command lines all over the place.
Fabian said that we could do something like:
"scripts": {
"start": "node build/index.js",
"build": "tsc",
"postinstall": "npm run build"
}
As of me writing this, I tested this and can state: postinstall is not required since build script is ran by Heroku. If you want to do it without build script, then you can use heroku-postbuild which will run after dependencies are installed there you run tsc to compile.
My problem was about missing Typescript npm modules. The Typescript compiler tsc was not found when deployed the app to Heroku.
The Heroku deploy process (rightly) does not install development dependencies, in my case the Typescript module was part of devDependencies and thus the tsc command was not running on the Heroku platform.
Solution 1
Add typescript to dependencies: npm i typescript -s
Solution 2
Open Heroku console:
Select console type:
Run the command npm i typescript && npm run tsc
Install typescript as a dev dependency (cf. https://www.typescriptlang.org/download). Once built, your app does not need typescript anymore!
npm install -D typescript
Then in your package.json:
{
"main": "index.js", // <- file will be generated at build time with `tsc`
"scripts": {
"build": "tsc",
"start": "node ."
"start:dev": "ts-node index.ts" // idem, install ts-node as a dev dependency
}
}
The key point here is "build": "tsc".
Why?
Heroku does install all dependencies during build and remove the dev dependencies before the app is deployed (source here).
Node.js deployments will automatically execute an app’s build script during build (since March 11. 2019 source here)
In package.json
"scripts": {
"tsc": "./node_modules/typescript/bin/tsc",
"postinstall": "npm run tsc"
},
Works for me for Heroku deployment.
Installing typescript npm install -D typescript and writing tsc in the build script "build": "tsc", does not work for me. Also, try to run npm i typescript && npm run tsc in the Heroku console which also does not work.
In my case, I remove some dependencies from "devDependencies" to "dependencies", so it goes like this:
"dependencies": {
// The other dependencies goes here, I don't touch them.
// But all TS dependencies I remove to here.
"ts-node": "^9.1.1",
"tsconfig-paths": "^3.9.0",
"typescript": "^4.2.3",
"ts-loader": "^8.0.18"
},