added extra labs

exercises/05_code_quality/currency/README.md

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+
+# Currency Converter
+
+This package converts from one currency to another using the current exchange rates.

exercises/05_code_quality/currency/index.js

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+
+'use strict'
+
+const request = require('request')
+const decimalPlaces = 2
+
+exports.convert = (base, symbol, units, callback) => {
+	try {
+		checkValidCurrencyCode(base, err => {
+			if (err) callback(err)
+			checkValidCurrencyCode(symbol, err => {
+				if (err) callback(err)
+				base = base.trim()
+				symbol = symbol.trim()
+				getData(`http://api.fixer.io/latest?base=${base}&symbols=${symbol}`, (err, data) => {
+					if (err) callback(err)
+					const obj = JSON.parse(data)
+					//printObject(obj)
+					const result = parseFloat((obj.rates[symbol] * units).toFixed(decimalPlaces))
+					//console.log(result)
+					callback(null, result)
+				})
+			})
+		})
+	} catch(err) {
+		console.log(err.message)
+	}
+}
+
+function checkValidCurrencyCode(code, callback) {
+	console.log(`currency: ${JSON.stringify(code)}`)
+	code = code.trim()
+	request('http://api.fixer.io/latest', (err, res, body) => {
+		if (err) callback(new Error('invalid API call'))
+		const rates = JSON.parse(body).rates
+		if (!rates.hasOwnProperty(code)) callback(new Error(`invalid currency code ${code}`))
+		callback(null, true)
+	})
+}
+
+function getData(url, callback) {
+	request(url, (err, res, body) => {
+		if (err) callback(new Error('invalid API call'))
+		callback(null, body)
+	})
+}
+
+function printObject(data) {
+	const indent = 2
+	const str = JSON.stringify(data, null, indent)
+	console.log(str)
+}
+

exercises/05_code_quality/currency/package.json

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+{
+  "name": "currency",
+  "version": "0.0.3",
+  "private": true,
+  "dependencies": {
+    "request": "^2.81.0"
+  },
+  "devDependencies": {
+    "jasmine": "^2.5.3",
+    "jasmine-console-reporter": "^1.2.7"
+  }
+}

exercises/05_code_quality/currency/spec/currency-spec.js

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+
+'use strict'
+
+// need to allow the use of arbitrary numbers when testing
+/* eslint no-magic-numbers: 0 */
+
+const currency = require('../index.js')
+
+describe('currency module', () => {
+	it('should return a number', done => {
+		currency.convert('GBP', 'USD', 100, (err, data) => {
+			try {
+				if(err) throw err // throw errors to the catch block
+				expect(data).toEqual(jasmine.any(Number))
+				expect(data).toBeGreaterThan(0)
+				done()
+			} catch(err) {
+				expect(true).toBe(false) // no error should be thrown
+			}
+		})
+	})
+
+	it('should return a value with 2 decimal places', done => {
+		currency.convert('GBP', 'USD', 111, (err, data) => {
+			try {
+				if(err) throw err // throw errors to the catch block
+				expect(data).toEqual(jasmine.any(Number))
+				expect(data).toBeGreaterThan(0)
+				expect(data).toEqual(parseFloat(data.toFixed(2)))
+				done()
+			} catch(err) {
+				expect(true).toBe(false) // no error should be thrown
+			}
+		})
+	})
+})

exercises/05_code_quality/currency/spec/jasmine.json

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+
+{
+	"spec_files": [
+		"spec/currency-spec.js"
+	],
+	"helpers": [
+		"helpers/**/*.js"
+	]
+}

exercises/05_code_quality/currency/spec/runTests.js

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+
+'use strict'
+
+const Jasmine = require('jasmine')
+const jasmine = new Jasmine()
+
+jasmine.loadConfigFile('spec/jasmine.json')
+
+const JasmineConsoleReporter = require('jasmine-console-reporter')
+const reporter = new JasmineConsoleReporter({
+	colors: true,
+	cleanStack: true,
+	verbosity: 4,
+	listStyle: 'indent',
+	activity: true
+})
+
+jasmine.addReporter(reporter)
+
+jasmine.execute()

exercises/05_code_quality/currencyTest/index.js

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+
+'use strict'
+
+const currency = require('currency')
+
+try {
+	getInput('enter base currency', (err, data) => {
+		if (err) throw err
+		const base = data
+		getInput('enter currency required', (err, data) => {
+			if (err) throw err
+ 			const symbol = data
+			getInput('enter amount to convert', (err, data) => {
+				if (err) throw err
+				const units = data
+				currency.convert(base, symbol, units, (err, data) => {
+					if (err) throw err
+					console.log(`${data} ${symbol}`)
+				})
+			})
+		})
+	})
+} catch(err) {
+	console.log(err.message)
+}
+
+
+function getInput(prompt, callback) {
+	try {
+		process.stdin.resume()
+		process.stdin.setEncoding('utf8')
+		process.stdout.write(`${prompt}: `)
+		process.stdin.on('data', text => callback(null, text.trim()))
+	} catch(err) {
+		callback(err)
+	}
+}

exercises/05_code_quality/currencyTest/package.json

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+{
+  "name": "currency-test",
+  "version": "1.0.0",
+  "description": "test for the local currency package",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "Mark J Tyers",
+  "license": "ISC",
+  "dependencies": {
+    "currency": "file:///Users/marktyers/Documents/304CEM/06 Writing Robust Code/currency"
+  }
+}

exercises/05_code_quality/shopping/debug.js

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+
+'use strict'
+
+const list = require('./modules/shopping')
+debugger
+list.add('bread')
+list.add('butter')
+debugger
+list.add('cheese')
+list.add('bread')
+list.add('bread')
+list.add('butter')
+debugger
+try {
+	list.decrement('bread', 2)
+	list.decrement('butter', 4)
+	list.decrement('jam', 3)
+} catch(err) {
+	console.log('ERROR: '+err.message)
+}
+
+const items = list.getAll()
+items.forEach( (element, index) => {
+	console.log(index+'. '+element.title+'\t x'+element.qty)
+})

exercises/05_code_quality/shopping/index.js

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+"use strict"
+
+const readline = require("readline-sync");
+
+const list = require('./modules/shopping');
+
+do 
+	{
+	var input = String(readline.question("enter command: ")).trim() 
+	if (input.indexOf('add ') == 0)  {
+			let space = input.indexOf(' ');
+		let item = input.substring(space).trim();
+		/* Let's echo the item details back to the user before adding it. Notice the use of Template Literals (https://goo.gl/Yjxa5o), a part of ECMA6. This allows you to include placeholders for variables without the need for concatenation. The string must be enclosed by backticks (`) */
+	console.log(`adding "${item}"`) 
+        list.add(item)
+	}
+	if (input.indexOf("list") == 0) {
+		const items = list.getAll()
+        let i = 1
+		for (var value of items) {
+            /* process.stdout.write prints to the terminal without adding a newline character at the end. the \t character inserts a tab and the \n character inserts a newline */
+	    	process.stdout.write(`${i}. ${value.title}`)
+			process.stdout.write(`\t${value.qty}\n`) 
+			i++ 
+	    }
+	}
+}  while (input !== "exit");

exercises/05_code_quality/shopping/modules/shopping.js

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+'use strict'
+
+/**
+ * Shopping Module.
+ * @module shopping
+ */
+
+/** this global 'map' object will be used to store the items and quantities. It stores each item against a named key. */
+var data = new Map();
+
+/** add a new item to the todo list. Notice that we are using the new 'Arrow Function' syntax from the ECMA6 specification. */
+exports.add = item  => {
+	/* check if the item is already in the list */
+	if (data.get(item) == undefined)
+	{
+		/* if the item is not found it is added to the list with its quantity set to 1 */
+		data.set(item, {title: item, qty: 1})
+	} 
+	else 
+	{
+		/* the item is already in the list so it is retrieved and the quantity is incremented */
+		let i = data.get(item)
+	    i.qty++
+		/* the new data is then stored in the map */
+		data.set(item, i)
+	}
+	return data.get(item)
+}
+
+
+/** calculates and returns the number of items in the list */
+exports.count = () => { 
+	/* the _Map_ object has a _size_ property that returns the number of items */
+	return data.size
+}
+
+/** empties the list */
+exports.clear = () => {
+	data = new Map()
+}
+
+/** Returns an array containing all todo items */
+exports.getAll = () => {
+	let data_array = []
+	for (var value of data.values()) {
+		data_array.push(value)
+	}
+	return data_array
+}
+
+/**
+ * Returns details for the named item.
+ * @param   {string} item - The item name to retrieve.
+ * @returns {string} The name of the item
+ * @throws  {InvalidItem} item not in list.
+ */
+exports.getItem = item => {
+	if (data.get(item) === undefined) {
+		throw new Error('item not in list')
+	}
+	return data.get(item)
+}
+
+/** Removes item with the corresponding name. */
+exports.removeItem = item => {
+	console.log('removeItem')
+	if (data.get(item) === undefined) {
+		throw new Error('item not in list')
+	}
+	data.delete(item)
+}
+
+/** Decrements the quantity of an item in the list. */
+exports.decrement = (item, count) => {
+	console.log(arguments)
+	if (item === undefined || count === undefined) {
+		throw new Error('function requires two parameters')
+	}
+	if (data.get(item) === undefined) {
+		throw new Error('item not in list')
+	}
+	if (isNaN(count)) {
+		throw new Error('second parameter should be a number')
+	}
+	count = parseInt(count)
+	let current = data.get(item)
+	if (current.qty <= count) {
+		data.delete(item)
+		return
+	}
+	current.qty = current.qty - count
+	data.set(item, current)
+}

exercises/05_code_quality/shopping/package.json

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+{
+  "name": "shopping",
+  "version": "1.0.0",
+  "description": "simple shopping list",
+  "main": "index.js",
+  "scripts": {
+    "app": "node index.js",
+    "lint": "node_modules/.bin/eslint modules/",
+    "test": "node_modules/.bin/jasmine-node spec --color --verbose --autotest --watch .",
+    "coverage": "./node_modules/.bin/istanbul cover -x **spec/** -x **index.js** -x **debug.js** ./node_modules/.bin/jasmine-node spec",
+    "doc": "node_modules/.bin/jsdoc modules/"
+  },
+  "keywords": [
+    "list",
+    "jasmine",
+    "module"
+  ],
+  "author": "Mark J Tyers",
+  "license": "ISC",
+  "dependencies": {
+    "readline-sync": "^1.2.22"
+  },
+  "devDependencies": {
+    "eslint": "^3.1.0",
+    "istanbul": "^0.4.0",
+    "jasmine-node": "^1.14.5",
+    "jsdoc": "^3.4.0",
+    "node-inspector": "^0.12.8"
+  }
+}