Merge pull request #30 from karlthomas3/main

Fixed implement input validation for division endpoint

__test__/math.test.ts

@@ -1,9 +1,11 @@
+/** @format */
+
 import {
 	addTwoNumbers,
 	divideTwoNumbers,
 	powerTwoNumbers,
 	multiplyTwoNumbers,
-	subtractTwoNumbers
+	subtractTwoNumbers,
 } from '../math.handler';
 
 /*
@@ -22,7 +24,8 @@ describe('test math handler', (): void => {
 		// number 3 using this function will result in the number 32. This is a
 		// very crude test to test our function as it could just be always giving
 		// out the number 32!
-		let a = 29, b = 3;
+		let a = 29,
+			b = 3;
 		let result = addTwoNumbers(a, b);
 		// The expect function will return a Jest object with the result we gave it
 		// to actually test if the result we gave it is what we want, we need to use
@@ -38,6 +41,7 @@ describe('test math handler', (): void => {
 	// The following tests have been collapsed for brevety
 	test('divide two numbers', (): void => {
 		expect(divideTwoNumbers(10, 2)).toBe(5);
+		expect(divideTwoNumbers(1, 0)).toBe(NaN);
 	});
 
 	test('sub two numbers', (): void => {

index.ts

@@ -1,11 +1,13 @@
+/** @format */
+
 import express, { Express, Request, Response } from 'express';
 // Import our library
 import {
 	addTwoNumbers,
 	divideTwoNumbers,
+	subtractTwoNumbers,
 	powerTwoNumbers,
 	multiplyTwoNumbers,
-	subtractTwoNumbers
 } from './math.handler';
 
 /*
@@ -64,7 +66,7 @@ app.get('/', (_req: Request, res: Response) => {
 	});
 });
 
-// This GET route is very flexible, it will answer any request going to 
+// This GET route is very flexible, it will answer any request going to
 // `/sum/*/*` and assign the wildcards into the parameters with the key given
 app.get('/sum/:a/:b', (req: Request, res: Response) => {
 	// Extract the request parameters
@@ -78,21 +80,30 @@ app.get('/sum/:a/:b', (req: Request, res: Response) => {
 		operation: 'success',
 		a,
 		b,
-		sum
+		sum,
 	});
 });
 
 // Handler for the division route.
 app.get('/div/:a/:b', (req: Request, res: Response) => {
 	const { a, b } = { a: req.params.a, b: req.params.b };
-	const division = divideTwoNumbers(Number(a), Number(b));
-	res.json({
-		message: 'Div Operation',
-		operation: 'success',
-		a,
-		b,
-		c: division
-	});
+	if (b == '0') {
+		res.json({
+			message: 'You cannot divide by zero',
+			operation: 'failure',
+			a,
+			b,
+		});
+	} else {
+		const division = divideTwoNumbers(Number(a), Number(b));
+		res.json({
+			message: 'Div Operation',
+			operation: 'success',
+			a,
+			b,
+			c: division,
+		});
+	}
 });
 
 // Handler for the subtraction route
@@ -111,14 +122,14 @@ subtraction
 // Handler for the exponencial route
 app.get('/power/:a/:b', (req: Request, res: Response) => {
 	const { a, b } = { a: Number(req.params.a), b: Number(req.params.b) };
- 	const exponencial = powerTwoNumbers(Number(a), Number(b));
- 	res.json({
- 		message: 'Power Operation',
- 		operation: 'success',
- 		a,
- 		b,
- 		exponencial
- 	});
+	const exponencial = powerTwoNumbers(Number(a), Number(b));
+	res.json({
+		message: 'Power Operation',
+		operation: 'success',
+		a,
+		b,
+		exponencial,
+	});
 });
 // Handler for the multiply endpoint
 app.get('/multiply/:a/:b', (req: Request, res: Response) => {
@@ -129,7 +140,7 @@ app.get('/multiply/:a/:b', (req: Request, res: Response) => {
 		operation: 'success',
 		a,
 		b,
-		c: multiplication
+		c: multiplication,
 	});
 });
 

math.handler.ts

@@ -1,12 +1,16 @@
-/*
-This file contains our wonderful maths library
-
-@see Math documentation: https://en.wikipedia.org/wiki/Mathematics
-*/
+/**
+ * This file contains our wonderful maths library
+ *
+ * @format
+ * @see Math documentation: https://en.wikipedia.org/wiki/Mathematics
+ */
 
 const addTwoNumbers = (a: number, b: number): number => a + b;
 
-const divideTwoNumbers = (a: number, b: number): number => a / b;
+const divideTwoNumbers = (a: number, b: number): number => {
+	if (b == 0) return NaN;
+	return a / b;
+};
 
 const subtractTwoNumbers = (a: number, b: number): number => a - b;
 
@@ -15,9 +19,9 @@ const powerTwoNumbers = (a: number, b: number): number => a ** b;
 const multiplyTwoNumbers = (a: number, b: number): number => a * b;
 
 export {
-  addTwoNumbers,
-  divideTwoNumbers,
-  powerTwoNumbers,
-  multiplyTwoNumbers,
-  subtractTwoNumbers
+	addTwoNumbers,
+	divideTwoNumbers,
+	powerTwoNumbers,
+	multiplyTwoNumbers,
+	subtractTwoNumbers,
 };