fixed errors and added solutions for 06_code_quality

exercises/06_code_quality/asyncFunctions.js

@@ -30,7 +30,7 @@ const checkValidCurrencyCode = code => new Promise( (resolve, reject) => {
 	request(baseURL, (err, res, body) => {
 		if (err) reject(new Error('invalid API call'))
 		const rates = JSON.parse(body).rates
-		if (!rates.hasOwnProperty(code)) it.throw(new Error(`invalid currency code ${code}`))
+		if (!rates.hasOwnProperty(code)) throw new Error(`invalid currency code ${code}`)
 		resolve()
 	})
 })

exercises/06_code_quality/todo/jsdoc.conf

@@ -0,0 +1,24 @@
+{
+    "plugins": ["jsdoc-route-plugin"],
+    "recurseDepth": 10,
+    "source": {
+        "include": [ "." ],
+        "exclude": [ "node_modules" ],
+        "includePattern": ".+\\.js(doc|x)?$",
+        "excludePattern": "(^|\\/|\\\\)_"
+    },
+    "sourceType": "module",
+    "tags": {
+        "allowUnknownTags": true,
+        "dictionaries": ["jsdoc","closure"]
+    },
+    "templates": {
+        "cleverLinks": false,
+        "monospaceLinks": false
+    },
+    "opts": {
+        "encoding": "utf8",
+        "destination": "./docs/jsdoc",
+        "recurse": true
+    }
+}

solutions/06_code_quality/asyncFunctions.js

@@ -0,0 +1,67 @@
+
+'use strict'
+
+const request = require('request')
+const readline = require('readline-sync')
+const fs = require('fs')
+
+const baseURL = 'https://api.exchangeratesapi.io/latest'
+
+async function main() {
+	try {
+		const base = await getInput('enter base currency')
+		await checkValidCurrencyCode(base)
+		const data = await getData(`${baseURL}?base=${base}`)
+		const rates = JSON.parse(data).rates
+		await printObject(data)
+		const to = await getInput('convert to')
+		await checkValidCurrencyCode(to)
+		console.log(to)
+		const amount = await getInput('enter exchange amount')
+		const decoder = await readObjectFromFile('currencies.json')
+		console.log(`${amount} ${decoder[base]} (${base}) is worth ${
+			(rates[to] * amount).toFixed(4)} ${decoder[to]} (${to})`)
+		process.exit()
+	} catch (err) {
+		console.log(`error: ${err.message}`)
+	}
+}
+
+const getInput = async prompt => readline.question(`${prompt}: `)
+
+const checkValidCurrencyCode = code => new Promise( (resolve, reject) => {
+	code = code.trim()
+	request(baseURL, (err, res, body) => {
+		if (err) reject(new Error('invalid API call'))
+		const rates = JSON.parse(body).rates
+		if (!rates.hasOwnProperty(code)) throw new Error(`invalid currency code ${code}`)
+		resolve()
+	})
+})
+
+const getData = url => new Promise( (resolve, reject) => {
+	request(url, (err, res, body) => {
+		if (err) reject(new Error('invalid API call'))
+		resolve(body)
+	})
+})
+
+const printObject = async data => {
+	const indent = 2
+	data = await JSON.parse(data)
+	const str = JSON.stringify(data, null, indent)
+	await new Promise( resolve => {
+		console.log(str)
+		resolve()
+	})
+
+}
+
+const readObjectFromFile = fileName => new Promise( (resolve, reject) => {
+	fs.readFile(fileName, 'utf-8', (err, content) => {
+		if (err) reject(new Error(err))
+		return resolve(JSON.parse(content))
+	})
+})
+
+main()

solutions/06_code_quality/nestedCallbacks.js

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+
+/* eslint max-lines-per-function: 0 */
+
+'use strict'
+
+const request = require('request')
+const readline = require('readline')
+const fs = require('fs')
+
+const io = { input: process.stdin, output: process.stdout }
+
+const read = readline.createInterface(io)
+read.question('input base currency: ', base => {
+	console.log(`You entered ${base}`)
+	read.close()
+	base = base.trim()
+	// now we need to check the code is valid
+	request('https://api.exchangeratesapi.io/latest', (err, res, body) => {
+		if (err) {
+			console.error(err.message)
+			process.exit()
+		}
+		const rates = JSON.parse(body).rates
+		if (!rates.hasOwnProperty(base)) {
+			console.error(`invalid currency code ${base}`)
+			process.exit()
+		}
+		// now we can get the currency rates
+		request(`https://api.exchangeratesapi.io/latest?base=${base}`, (err, res, body) => {
+			if (err) {
+				console.error(err.message)
+				process.exit()
+			}
+			body = JSON.parse(body)
+			console.log(body)
+			// lets ask another question
+			const read = readline.createInterface(io)
+			read.question('convert to: ', convertTo => {
+				read.question('amount to convert: ', amount => {
+					read.close()
+					fs.readFile('currencies.json', 'utf8', (err, content) => {
+						if(err) console.error(error.message)
+						const decoder = JSON.parse(content)
+						console.log(`${amount} ${decoder[base]} (${base}) is worth ${
+							(body.rates[convertTo] * amount).toFixed(4)} ${decoder[convertTo]} (${convertTo})`)
+					})
+				})
+			})
+		})
+	})
+})

solutions/06_code_quality/promises.js

@@ -0,0 +1,70 @@
+
+'use strict'
+
+const request = require('request')
+const readline = require('readline')
+const fs = require('fs')
+
+const baseURL = 'https://api.exchangeratesapi.io/latest'
+
+const getInput = prompt => new Promise(resolve => {
+	const read = readline.createInterface({ input: process.stdin, output: process.stdout })
+	read.question(`${prompt}: `, value => {
+		console.log(`You entered ${value}`)
+		read.close()
+		return resolve(value)
+	})
+})
+
+const checkValidCurrencyCode = code => new Promise( (resolve, reject) => {
+	code = code.trim()
+	request(baseURL, (err, res, body) => {
+		if (err) reject(new Error('invalid API call'))
+		const rates = JSON.parse(body).rates
+		if (!rates.hasOwnProperty(code)) reject(new Error(`invalid currency code ${code}`))
+		return resolve(code)
+	})
+})
+
+const getData = code => new Promise( (resolve, reject) => {
+	request(`${baseURL}?base=${code}`, (err, res, body) => {
+		if (err) reject(new Error('invalid API call'))
+		return resolve(body)
+	})
+})
+
+const printObject = data => new Promise( resolve => {
+	const indent = 2
+	data = JSON.parse(data)
+	const str = JSON.stringify(data, null, indent)
+	console.log(str)
+	return resolve()
+})
+
+const exit = () => new Promise( () => {
+	process.exit()
+})
+
+const readObjectFromFile = fileName => new Promise( (resolve, reject) => {
+	fs.readFile(fileName, 'utf-8', (err, content) => {
+		if (err) reject(new Error(err))
+		return resolve(JSON.parse(content))
+	})
+})
+
+getInput('enter base currency')
+	.then(checkValidCurrencyCode)
+	.then(code => this.base = code)
+	.then( () => getData(this.base))
+	.then( body => this.rates = JSON.parse(body).rates)
+	.then( () => getInput('convert to'))
+	.then(checkValidCurrencyCode)
+	.then( code => this.convertTo = code)
+	.then( () => readObjectFromFile('currencies.json'))
+	.then(fileObject => this.decoder = fileObject)
+	.then( () => getInput('enter exchange amount'))
+	.then( amount => console.log(`${amount} ${this.decoder[this.base]} (${this.base}) is worth ${
+		(this.rates[this.convertTo] * amount).toFixed(4)} ${this.decoder[this.convertTo]} (${this.convertTo})`))
+	.then(exit)
+	.catch(err => console.error(`error: ${err.message}`))
+	  .then(exit)

solutions/06_code_quality/todo/index.js

@@ -0,0 +1,80 @@
+#!/usr/bin/env node
+
+/**
+ * Server index module
+ * @module index
+ */
+
+const Koa = require('koa')
+const Router = require('koa-router')
+const stat = require('koa-static')
+const bodyParser = require('koa-bodyparser')
+const handlebars = require('koa-hbs-renderer')
+
+const app = new Koa()
+const router = new Router()
+app.use(stat('public'))
+app.use(bodyParser())
+app.use(handlebars({ paths: { views: `${__dirname}/views` } }))
+app.use(router.routes())
+
+// The through which the server will communicate
+const port = 8080
+
+const List = require('./modules/list').List
+const list = new List()
+
+/**
+ * Get the home page
+ * @name Home
+ * @route {GET} /
+ */
+router.get('/', ctx => {
+	try {
+		const items = list.getAll()
+		console.log(items)
+		const data = {items}
+		ctx.render('home', data)
+	} catch(err) {
+		console.log(err.message)
+		ctx.render('home', {msg: err.message})
+	}
+})
+
+/**
+ * Add an item to the list
+ * @name Add item
+ * @route {POST} /
+ */
+router.post('/', ctx => {
+	try {
+		const body = ctx.request.body
+		console.log(body)
+		list.add(body.item, body.qty)
+		ctx.redirect('/')
+	} catch(err) {
+		console.log(err.message)
+		ctx.redirect(`/?msg=${err.message}`)
+	}
+})
+
+/**
+ * Delete an item from the list
+ * @name Delete item
+ * @route {get} /delete/:key
+ */
+router.get('/delete/:key', ctx => {
+	try {
+		const key = ctx.params.key
+		console.log(`key: ${key}`)
+		list.delete(key)
+		ctx.redirect('/?msg=item deleted')
+	} catch(err) {
+		console.log(err.message)
+		ctx.redirect(`/${err.message}`)
+	}
+})
+
+module.exports = app.listen(port, () => {
+	console.log(`listening on port ${port}`)
+})

solutions/06_code_quality/todo/list.js

@@ -0,0 +1,53 @@
+
+/**
+ * Class representing a list of items.
+ * */
+class List {
+
+	/**
+	 * Create a list.
+	 */
+	constructor() {
+		this.items = []
+	}
+
+	/**
+	 * Add an item to the list.
+	 * @param {String} item - The name of the eitem.
+	 * @param {Number} qty - The number of items to add.
+	 */
+	add(item, qty) {
+		const data = {item: item, qty: qty}
+		this.items.push(data)
+	}
+
+	/**
+	 * Return the list of items.
+	 * @return {Array.<{item: String, qty: Number}>} An array containing the items.
+	 */
+	getAll() {
+		return this.items.map( (element, index) => ({key: index, item: element.item, qty: element.qty}))
+	}
+
+	/**
+	 * Delete an item from the list.
+	 * @param {Number} id - The index of the deletable item
+	 */
+	delete(id) {
+		this.items.splice(id, 1)
+	}
+
+	/**
+	 * Return the number of items in the list
+	 * @return {Number} The number of items in the list
+	 */
+	count() {
+		return this.items.count
+	}
+
+}
+
+// exporting the class by name adds the name to the documentation
+module.exports = {
+	List
+}