Angular 2 + Rails 5 Heroku部署错误（bash：npm：未找到命令）

Question

Deploying an Angular2 on Rails5 app to Heroku resulted in a successful build without errors. I then set up my PG database without incident. When trying to access the app, I get the below stack trace from the Heroku app log. Trying to figure out why the npm: command not found is thrown.

2016-11-25T00:30:40.044683+00:00 heroku[web.1]: State changed from  
crashed to starting
2016-11-25T00:30:52.371722+00:00 heroku[web.1]: Starting process with  
command `npm start`
2016-11-25T00:30:55.294652+00:00 app[web.1]: bash: npm: command not 
found
2016-11-25T00:30:55.439571+00:00 heroku[web.1]: State changed from  
starting to crashed
2016-11-25T00:30:55.409349+00:00 heroku[web.1]: Process exited with 
status 127

package.json head

{
 "name": "raven",
 "version": "0.0.1",
 "license": "MIT",
 "angular-cli": {},
 "scripts": {
   "start": "ng serve --proxy-config proxy.conf.json",
   "start-phone": "ng serve --proxy-config proxy.conf.json --host  
   0.0.0.0",
   "lint": "tslint \"src/**/*.ts\"",
   "test": "ng test",
   "pree2e": "webdriver-manager update",
   "e2e": "protractor",
   "heroku-postbuild": "ng build --prod"
 },

When trying to hit the app url, the Heroku app log throws the below error code:

2016-11-25T00:35:43.573863+00:00 heroku[router]: at=error code=H10   
desc="App crashed" method=GET path="/" host=shrouded-shelf- 
15670.herokuapp.com request_id=92fba3d2-08e4-479d-8484-33f093c9c823  
fwd="75.173.239.214" dyno= connect= service= status=503 bytes=

Update: I added a Procfile to the project's root directory with the below entries. The rails app now starts as a result of the entry but still getting bash: npm: command not found.

Procfile:

web: sh -c 'cd ./client/ && exec npm start'
api: rails s -p 3000

Remaining error:

2016-11-25T02:17:14.955048+00:00 heroku[web.1]: Starting process with  
command `sh -c 'cd ./client/ && exec npm start'`
2016-11-25T02:17:17.066308+00:00 heroku[web.1]: Process exited with 
status 127
2016-11-25T02:17:16.983254+00:00 app[web.1]: sh: 1: exec: npm: not 
found
2016-11-25T02:17:17.078868+00:00 heroku[web.1]: State changed from  
starting to crashed

Answer 1

Modified package.json to account for starting the Angular2 app during the heroku post-build step. Keeping it after && ensured that it would only kickoff if the preceding step completed.

"heroku-postbuild": "ng build --prod && npm start"