Assets not found when deploying Sails app to Heroku - heroku

Question

I'm pretty new in Sails.
I've created a new web-app from the Sails template and tried to upload it to Heroku. Everything was fine except for the assets, none of the assets are found (js, css, images, etc).
I've found out that Sails uses Grunt for copying the files to a .tmp folder. I've checked and I have Grunt added to my package.json file. I've also added a Procfile wit the web: node app.js command and the NODE_ENV variable it's pointing to production in Heroku.
I didn't changed any of the Grunt tasks, the Gruntfile.js file and the /tasks directory are by default.
Any ideas of what else I could check?

Answer 1

I solved this issue through a different mean. On top of including some of the grunt deps in the OP's answer, I added postinstall in the scripts section of package.json:
"scripts": {
"start": "NODE_ENV=production node app.js",
"test": "npm run lint && npm run custom-tests && echo 'Done.'",
"lint": "eslint . --max-warnings=0 --report-unused-disable-directives && echo '✔ Your .js files look so good.' && htmlhint -c ./.htmlhintrc views/*.ejs && htmlhint -c ./.htmlhintrc views/**/*.ejs && htmlhint -c ./.htmlhintrc views/**/**/*.ejs && htmlhint -c ./.htmlhintrc views/**/**/**/*.ejs && htmlhint -c ./.htmlhintrc views/**/**/**/**/*.ejs && htmlhint -c ./.htmlhintrc views/**/**/**/**/**/*.ejs && htmlhint -c ./.htmlhintrc views/**/**/**/**/**/**/*.ejs && echo '✔ So do your .ejs files.' && lesshint assets/styles/ --max-warnings=0 && echo '✔ Your .less files look good, too.'",
"custom-tests": "echo \"(No other custom tests yet.)\" && echo",
"postinstall": "grunt build", // added this
...
The effect of this on heroku is the required running of the grunt task build, which compile and copy the assets to the appropriately referenced location (i.e.: .tmp)

Answer 2

The solution was pretty easy. Turns out that I didn't had the Grunt dependencies added for production env, only for development env in my package.json. I've added them and worked perfectly.
"dependencies": {
"#sailshq/connect-redis": "^3.2.1",
"#sailshq/lodash": "^3.10.3",
"#sailshq/socket.io-redis": "^5.2.0",
"async": "2.0.1",
"sails": "^1.0.2",
"sails-hook-apianalytics": "^2.0.0",
"sails-hook-organics": "^0.13.0",
"sails-hook-orm": "^2.0.0-16",
"sails-hook-sockets": "^1.4.0",
"sails-postgresql": "^1.0.1",
"grunt": "1.0.1", // I've added these two lines
"sails-hook-grunt": "^3.0.2" // I've added these two lines
},
"devDependencies": {
"#sailshq/eslint": "^4.19.3",
"#sailshq/htmlhint": "^0.9.16",
"#sailshq/lesshint": "^4.6.6",
"grunt": "1.0.1",
"sails-hook-grunt": "^3.0.2"
},