Mediastream challenge Jalid Chaer

.eslintrc.js

@@ -3,22 +3,20 @@ module.exports = {
     browser: true,
     commonjs: true,
     es2021: true,
-    node: true
+    node: true,
   },
   extends: [
     'plugin:react/recommended',
     'plugin:jest/recommended',
-    'standard'
+    'standard',
+    'plugin:prettier/recommended',
   ],
   parserOptions: {
     ecmaFeatures: {
-      jsx: true
+      jsx: true,
     },
-    ecmaVersion: 12
+    ecmaVersion: 12,
   },
-  plugins: [
-    'react', 'react-hooks', 'jest'
-  ],
-  rules: {
-  }
-}
+  plugins: ['react', 'react-hooks', 'jest'],
+  rules: {},
+};

.prettierignore

@@ -0,0 +1 @@
+node_modules/*

.prettierrc

@@ -0,0 +1,9 @@
+{
+    "printWidth": 80,
+    "tabWidth": 2,
+    "useTabs": false,
+    "semi": true,
+    "singleQuote": true,
+    "trailingComma": "all",
+    "bracketSpacing": true
+}

01-basic-cs/index.js

@@ -1,19 +1,26 @@
-'use strict'
+'use strict';
 
-const _ = require('lodash') // https://lodash.com/docs/4.17.4
-const assert = require('assert')
+const _ = require('lodash'); // https://lodash.com/docs/4.17.4
+const assert = require('assert');
 
-const database = require('./database.json')
+const database = require('./database.json');
 
-const total = 0 // TODO
+const hats = _.flatMap(database, 'hats');
+const countOfHats = _.countBy(hats, 'id');
+const mostTopSelling = _(Object.values(countOfHats))
+  .sortBy()
+  .takeRight(3)
+  .value();
+
+const total = _(mostTopSelling).sum();
 
 // Throws error on failure
-assert.equal(total, 23, `Invalid result: ${total} != 23`)
+assert.equal(total, 23, `Invalid result: ${total} != 23`);
 
-console.log('Success!')
+console.log('Success!');
 
 /**
  * Time and space complexity in O() notation is:
- *   - time complexity: TODO
- *   - space complexity: TODO
+ *   - time complexity: O(n log n)
+ *   - space complexity: O(n)
  */

01-basic-cs/utils/seed.js

@@ -1,24 +1,24 @@
-'use strict'
+'use strict';
 
-const faker = require('faker')
-const _ = require('lodash')
+const faker = require('faker');
+const _ = require('lodash');
 
 const AMMOUNT = {
   USERS: 50,
-  HATS: 30
-}
+  HATS: 30,
+};
 
-const hats = _.times(AMMOUNT.HATS, n => ({
+const hats = _.times(AMMOUNT.HATS, (n) => ({
   id: faker.random.uuid(),
   name: faker.commerce.productName(),
   material: faker.commerce.productMaterial(),
-  price: faker.commerce.price()
-}))
+  price: faker.commerce.price(),
+}));
 
-const users = _.times(AMMOUNT.USERS, n => ({
+const users = _.times(AMMOUNT.USERS, (n) => ({
   id: faker.random.uuid(),
   email: faker.internet.email(),
-  hats: _.sampleSize(hats, _.random(0, 5))
-}))
+  hats: _.sampleSize(hats, _.random(0, 5)),
+}));
 
-console.log(JSON.stringify(users, null, 2))
+console.log(JSON.stringify(users, null, 2));

02-nodejs/index.js

@@ -1,12 +1,38 @@
-'use strict'
+'use strict';
 
-const express = require('express')
+const express = require('express');
+const fastcsv = require('fast-csv');
 
-const User = require('./models/User')
+const User = require('./models/User');
 
 // Setup Express.js app
-const app = express()
+const app = express();
 
 // TODO: everything else
 
-app.listen(3000)
+app.get('/users', async (req, res) => {
+  try {
+    const users = await User.find({}).select('name email').lean();
+
+    if (users.length > 0) {
+      res.setHeader('Content-Type', 'text/csv');
+      res.setHeader('Content-Disposition', 'attachment; filename=users.csv');
+      const csvStream = fastcsv.format({ headers: true });
+
+      csvStream.pipe(res);
+
+      users.forEach((user) => {
+        csvStream.write(user);
+      });
+
+      csvStream.end();
+    } else {
+      res.status(404).send('No data to export');
+    }
+  } catch (error) {
+    console.error(error);
+    res.status(500).send('Server Error');
+  }
+});
+
+app.listen(3000);

02-nodejs/models/User.js

@@ -1,12 +1,12 @@
-const mongoose = require('mongoose')
+const mongoose = require('mongoose');
 
 // Setup database
-mongoose.Promise = Promise
-mongoose.connect('mongodb://localhost/mediastream-challenge')
+mongoose.Promise = Promise;
+mongoose.connect('mongodb://localhost/mediastream-challenge');
 
 const User = mongoose.model('User', {
   name: String,
-  email: String
-})
+  email: String,
+});
 
-module.exports = User
+module.exports = User;

02-nodejs/utils/seed.js

@@ -1,19 +1,19 @@
-'use strict'
+'use strict';
 
-const faker = require('faker')
-const _ = require('lodash')
-const User = require('../models/User')
+const faker = require('faker');
+const _ = require('lodash');
+const User = require('../models/User');
 
 const AMMOUNT = {
-  USERS: 100000
-}
+  USERS: 100000,
+};
 
-const users = _.times(AMMOUNT.USERS, n => ({
+const users = _.times(AMMOUNT.USERS, (n) => ({
   name: faker.name.findName(),
-  email: faker.internet.email()
-}))
+  email: faker.internet.email(),
+}));
 
 User.insertMany(users).then(() => {
-  console.log('Seed complete')
-  process.exit(0)
-}, console.error.bind(console))
+  console.log('Seed complete');
+  process.exit(0);
+}, console.error.bind(console));