为什么将我的 Angular 项目部署到 Heroku 时出现 ng not found 错误？

Question

My project layout looks like this:

package.json (A)
index.js
client
> package.json (B)

with my outer package.json (A) looking like this:

{
  "name": "---",
  "version": "1.0.0",
  "description": "---",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "build": "cd client && ng build --prod && cd .. && node index.js"
  },
  "repository": {
    "type": "git",
    "url": "---"
  },
  "author": "---",
  "license": "ISC",
  "bugs": {
    "url": "---"
  },
  "homepage": "---",
  "dependencies": {
    "axios": "^0.19.2",
    "cors": "^2.8.5",
    "dotenv": "^8.2.0",
    "express": "^4.17.1",
    "mongoose": "^5.9.14"
  }
}

while the package.json (B) inside the client folder that holds the angular project looks like this:

{
  "name": "client",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/cli": "~9.0.6",
    "@angular/compiler-cli": "~9.0.6",
    "@angular/animations": "~9.0.6",
    "@angular/common": "~9.0.6",
    "@angular/compiler": "~9.0.6",
    "@angular/core": "~9.0.6",
    "@angular/fire": "^6.0.0",
    "@angular/forms": "~9.0.6",
    "@angular/platform-browser": "~9.0.6",
    "@angular/platform-browser-dynamic": "~9.0.6",
    "@angular/router": "~9.0.6",
    "firebase": "^7.14.4",
    "rxjs": "~6.5.4",
    "tslib": "^1.10.0",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.900.6",
    "@angular/cli": "~9.0.6",
    "@angular/compiler-cli": "~9.0.6",
    "@angular/language-service": "~9.0.6",
    "@types/node": "^12.11.1",
    "@types/jasmine": "~3.5.0",
    "@types/jasminewd2": "~2.0.3",
    "codelyzer": "^5.1.2",
    "jasmine-core": "~3.5.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~2.1.0",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.2",
    "protractor": "~5.4.3",
    "ts-node": "~8.3.0",
    "tslint": "~5.18.0",
    "typescript": "~3.7.5"
  }
}

Looking up other threads that have asked similar things, most of them said that I needed to move the @angular/cli and @angular/compiler-cli from devDependencies to dependencies, which is what I did.

However, when Heroku runs the script

"build": "cd client && ng build --prod && cd .. && node index.js"

I'm not sure why I keep getting the error that ng was not found. Another thing I tried was to add the preinstall script to package.json (A)

"preinstall": "npm install -g angular-cli"

which removed the ng not found error, but instead I got an error saying that the build command would only work inside of an angular-cli project, which is making me think that maybe the change directory isn't working? This is really confusing to me, because npm run build works fine for me...

Answer 1

I messed around a bit and finally got it to work. My solution was to change my package.json (A) scripts to

"scripts": {
    "start": "node index.js",
    "build": "cd client && npm install && npm run build --prod"
  },

and to move literally everything in devDependencies in package.json (B) into the dependencies folder.