resolve path of a file in node js

const comparePassword = async (password, hash) => {
    try {
        // Compare password
        return await bcrypt.compare(password, hash);
    } catch (error) {
        console.log(error);
    }

    // Return false if error
    return false;
};

//use case
(async () => {
    // Hash fetched from DB
    const hash = `$2b$10$5ysgXZUJi7MkJWhEhFcZTObGe18G1G.0rnXkewEtXq6ebVx1qpjYW`;

    // Check if password is correct
    const isValidPass = await comparePassword('123456', hash);

    // Print validation status
    console.log(`Password is ${!isValidPass ? 'not' : ''} valid!`);
    // => Password is valid!
})();

const sessionMiddleware = expressSession({
    secret: 'Tecky Academy teaches typescript',
    resave:true,
    saveUninitialized:true,
    cookie:{secure:false}
});

app.use(sessionMiddleware);

io.use((socket,next)=>{
    let req = socket.request as express.Request
    let res = req.res as express.Response
    sessionMiddleware(req, res, next as express.NextFunction
});
//...
io.on('connection', function (socket) {
    // You can set any values you want to session here.
    const req = socket.request as express.Request;
    req.session['key'] = 'XXX';
    // There is no auto save for session.
    socket.request.session.save();

    // You can also send data using socket.emit() although it is not very useful
    socket.emit('any-key','values');
    socket.on("disconnect",()=>{
        //... rest of the code
    })
});

var fullUrl = req.protocol + '://' + req.get('host') + req.originalUrl;

var express = require('express');
var app = express();

app.enable('trust proxy'); //to detect if req.secure is true/false

//Block http requests. Only allow https requests
app.use(function (req, res, next) {
	if (req.headers['x-forwarded-proto'] !== 'https'){
      return res.status(404).send('Not found');
    } else {
    next();
    }
})

exports = module.exports = app;

const express = require('express')
const { graphqlHTTP } = require("express-graphql");
const {
  GraphQLSchema,
  GraphQLObjectType,
  GraphQLString,
  GraphQLList,
  GraphQLInt,
  GraphQLNonNull
} = require('graphql')
const app = express()
const port = 3000

// Sample Data
const authors = [
	{ id: 1, name: 'Dan Brown' },
	{ id: 2, name: 'J. R. R. Tolkien' },
	{ id: 3, name: 'Brent Weeks' }
]

const books = [
	{ id: 1, name: 'The Lost Symbol', authorId: 1 },
	{ id: 2, name: 'Angels and Demons', authorId: 1 },
	{ id: 3, name: 'The Davinci Code', authorId: 1 },
	{ id: 4, name: 'The Fellowship of the Ring', authorId: 2 },
	{ id: 5, name: 'The Two Towers', authorId: 2 },
	{ id: 6, name: 'The Return of the King', authorId: 2 },
	{ id: 7, name: 'The Way of Shadows', authorId: 3 },
	{ id: 8, name: 'Beyond the Shadows', authorId: 3 }
]

const BookType = new GraphQLObjectType({
  name: 'Book',
  description: 'This represents a book written by an author',
  fields: () => ({
    id: { type: GraphQLNonNull(GraphQLInt) },
    name: { type: GraphQLNonNull(GraphQLString) },
    authorId: { type: GraphQLNonNull(GraphQLInt) },
    author: {
      type: AuthorType, // AuthorType is defined below the same way that BookType is defined above
      resolve: (book) => {
        return authors.find(author => author.id === book.authorId)
      }
    }
  })
})

const AuthorType = new GraphQLObjectType({
  name: 'Author',
  description: 'This represents the author of a book',
  fields: () => ({
    id: { type: GraphQLNonNull(GraphQLInt) },
    name: { type: GraphQLNonNull(GraphQLString) }
  })
})

const RootQueryType = new GraphQLObjectType({
  name: 'Query',
  description: 'Root Query',
  fields: () => ({
    books: {
      type: new GraphQLList(BookType),
      description: "List of books",
      resolve: () => books
    }
  })
})

const schema = new GraphQLSchema({
  query: RootQueryType
})



app.use('/graphql', graphqlHTTP({
  schema: schema,
  graphiql: true
}))


app.get('/', (req, res) => {
  res.send(`<a href="http://localhost:${port}/graphql">GraphiQL</a>`)
})

// QUERY:
// 
// {
// 	books {
//     id
//   	name
//     author {
//       name
//     }
// 	}
// }

// RESULT
// 
// {
//   "data": {
//     "books": [
//       {
//         "id": 1,
//         "name": "The Lost Symbol",
//         "author": {
//           "name": "Dan Brown"
//         }
//       },
//       {
//         "id": 2,
//         "name": "Angels and Demons",
//         "author": {
//           "name": "Dan Brown"
//         }
//       }, //...
//     ]
//   }
// }

app.listen(port, () => {
  console.log(`App listening on http://localhost:${port}`)
});

// BASH
mkdir src
mkdir build
touch src/index.ts
touch .gitignore
touch README.md
tsc -y
npm init -y
npm install nodemon concurrently @types/express --save-dev

// package.json
...
"scripts": {
  "start:build": "tsc -w",
  "start:run": "nodemon ./build/index.js",
  "start": "concurrently npm:start:*"
},
...

// tsconfig.json
...
"outDir": "./build",
"rootDir": "./src",
...

// .gitignore
node_modules
*.env

// README.md
### Start
```bash
npm run start
```

// src/index.ts
import express from 'express'
const port = 3000
const app = express()

console.log("Hello, World!!!")

logSomething("This is a string that I'm logging")

app.listen(port, () => {
  console.log(`Listening on port ${port}`)
})

const appRoot = require('app-root-path')
const multer = require('multer')

const fileController = require(`${appRoot}/src/controllers/FileController.js`)
const INPUT_NAME = 'photos'

const fileStorage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'files')
  },
  filename: (req, file, cb) => {
    cb(null, file.originalname + '-' + (new Date()).toISOString())
  }
})

const fileFilter = (req, file, cb) => {
  if (['image/png', 'image/jpg', 'image/jpeg'].includes(file.mimetype)) {
    cb (null, true)
  } else {
    cb (null, false)
  }
}



module.exports = (app) => {
  app.use(multer({storage: fileStorage, fileFilter: fileFilter}).single('photo'))
  app.post('/upload', fileController.upload)
  app.post('/download', fileController.download)
}

const fs = require('fs')

exports.download = (req, res, next) => {
  console.log('fileController.download: started')
  const path = req.body.path
  const file = fs.createReadStream(path)
  const filename = (new Date()).toISOString()
  res.setHeader('Content-Disposition', 'attachment: filename="' + filename + '"')
  file.pipe(res)
}

function promiseWrapper(fn) {
    return (req, res, next) => {
         fn(req, res).catch(next);
    };
}

// in app.js
hbs.registerHelper(`ifEquals`, function (a, b, opts) {
    if (a.toString() === b.toString()) {
        return opts.fn(this);
    }
    return opts.inverse(this);
});

// in hbs template
{{#ifEquals name 'Foo'}}
      true
{{else}}
      false
{{/ifEquals}}

//cons name = 'me'

{{log 'author = ' name }}

//author = me

hbs.registerHelper(`iff`, function (a, operator, b, opts) {
    let bool = false;
    a.toString();
    b.toString();
    switch (operator) {
        case `===`:
            bool = a === b;
            break;
        case `>`:
            bool = a > b;
            break;
        case `<`:
            bool = a < b;
            break;
        default:
            bool = a === b;
    }

    if (bool) {
        return opts.fn(this);
    }
    return opts.inverse(this);
});

{{#iff value1 '>' value2}}
do the thing
{{/iff}}

// create a schema
const eventSchema = new Schema({
  name: String,
  slug: {
    type: String,
    unique: true
  },
  description: String
});

// create the model
const eventModel = mongoose.model('Event', eventSchema);

// middleware -----
// make sure that the slug is created from the name
eventSchema.pre('save', function(next) {
  this.slug = slugify(this.name);
  next();
});

// function to slugify a name
function slugify(text) {
  return text.toString().toLowerCase()
    .replace(/\s+/g, '-')           // Replace spaces with -
    .replace(/[^\w\-]+/g, '')       // Remove all non-word chars
    .replace(/\-\-+/g, '-')         // Replace multiple - with single -
    .replace(/^-+/, '')             // Trim - from start of text
    .replace(/-+$/, '');            // Trim - from end of text
}