added descriptive comments to app functions

config/database.js

@@ -1,5 +1,6 @@
 const mongoose = require("mongoose");
 
+// connect to database
 const connectDB = async () => {
   try {
     const conn = await mongoose.connect(process.env.DB_STRING, {

config/passport.js

@@ -2,6 +2,7 @@ const LocalStrategy = require("passport-local").Strategy;
 const mongoose = require("mongoose");
 const User = require("../models/User");
 
+// configure passport authentication
 module.exports = function (passport) {
   passport.use(
     new LocalStrategy({ usernameField: "email" }, (email, password, done) => {
@@ -31,10 +32,12 @@ module.exports = function (passport) {
     })
   );
 
+  // serialize user id for session, essentially reduces what is stored in session memory to just the userid which can then be used to retrieve the full user data when needed for requests
   passport.serializeUser((user, done) => {
     done(null, user.id);
   });
 
+  // retrieves the user data via the serialized userid data
   passport.deserializeUser((id, done) => {
     User.findById(id, (err, user) => done(err, user));
   });

controllers/auth.js

@@ -2,6 +2,7 @@ const passport = require("passport");
 const validator = require("validator");
 const User = require("../models/User");
 
+// render login page
 exports.getLogin = (req, res) => {
   if (req.user) {
     return res.redirect("/profile");
@@ -11,6 +12,7 @@ exports.getLogin = (req, res) => {
   });
 };
 
+// handle login form submission
 exports.postLogin = (req, res, next) => {
   const validationErrors = [];
   if (!validator.isEmail(req.body.email))
@@ -44,6 +46,7 @@ exports.postLogin = (req, res, next) => {
   })(req, res, next);
 };
 
+// log user out and destroy session
 exports.logout = (req, res) => {
   req.logout(() => {
     console.log('User has logged out.')
@@ -56,6 +59,7 @@ exports.logout = (req, res) => {
   });
 };
 
+// render signup page
 exports.getSignup = (req, res) => {
   if (req.user) {
     return res.redirect("/profile");
@@ -65,6 +69,7 @@ exports.getSignup = (req, res) => {
   });
 };
 
+// handle signup form submission
 exports.postSignup = (req, res, next) => {
   const validationErrors = [];
   if (!validator.isEmail(req.body.email))

controllers/home.js

@@ -1,4 +1,5 @@
 module.exports = {
+  // renders home page
   getIndex: (req, res) => {
     res.render("index.ejs");
   },

controllers/posts.js

@@ -2,6 +2,7 @@ const cloudinary = require("../middleware/cloudinary");
 const Post = require("../models/Post");
 
 module.exports = {
+  // gets user profile with posts
   getProfile: async (req, res) => {
     try {
       const posts = await Post.find({ user: req.user.id });
@@ -10,6 +11,7 @@ module.exports = {
       console.log(err);
     }
   },
+  // get all posts for feed
   getFeed: async (req, res) => {
     try {
       const posts = await Post.find().sort({ createdAt: "desc" }).lean();
@@ -18,6 +20,7 @@ module.exports = {
       console.log(err);
     }
   },
+  // get single post
   getPost: async (req, res) => {
     try {
       const post = await Post.findById(req.params.id);
@@ -26,6 +29,7 @@ module.exports = {
       console.log(err);
     }
   },
+  // create new post with image upload
   createPost: async (req, res) => {
     try {
       // Upload image to cloudinary
@@ -45,6 +49,7 @@ module.exports = {
       console.log(err);
     }
   },
+  // increment post likes
   likePost: async (req, res) => {
     try {
       await Post.findOneAndUpdate(
@@ -59,6 +64,7 @@ module.exports = {
       console.log(err);
     }
   },
+  // delete post and image
   deletePost: async (req, res) => {
     try {
       // Find post by id

middleware/auth.js

@@ -1,11 +1,13 @@
 module.exports = {
+  // check if user is authenticated
   ensureAuth: function (req, res, next) {
     if (req.isAuthenticated()) {
       return next();
     } else {
       res.redirect("/");
     }
   },
+  // check if user is not authenticated
   ensureGuest: function (req, res, next) {
     if (!req.isAuthenticated()) {
       return next();

middleware/multer.js

@@ -3,7 +3,7 @@ const path = require("path");
 
 module.exports = multer({
   storage: multer.diskStorage({}),
-  fileFilter: (req, file, cb) => {
+  fileFilter: (req, file, cb) => { // check file type is a compatible image
     let ext = path.extname(file.originalname);
     if (ext !== ".jpg" && ext !== ".jpeg" && ext !== ".png") {
       cb(new Error("File type is not supported"), false);

models/User.js

@@ -9,6 +9,7 @@ const UserSchema = new mongoose.Schema({
 
 // Password hash middleware.
 
+// hash password before saving
 UserSchema.pre("save", function save(next) {
   const user = this;
   if (!user.isModified("password")) {
@@ -30,6 +31,7 @@ UserSchema.pre("save", function save(next) {
 
 // Helper method for validating user's password.
 
+// compare password with hash
 UserSchema.methods.comparePassword = function comparePassword(
   candidatePassword,
   cb