feat: email validator (#526)

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 
 ## [Unreleased]
 
+### :zap: Added
+
+- `toBeEmail` - Expect a value to be an email (contributed by [@alandev2](https://github.com/alandev2))
+
 ## [1.0.4] - 2019-12-27
 
 ### :policeman: Security
@@ -34,7 +38,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 
 ## [1.0.0] - 2017-06-22
 
-### Added
+### :zap: Added
 
 - `toBeTrue` - Expect a condition to be true
 - `toBeFalse` - Expect a condition to be false

src/Expect.ts

@@ -79,3 +79,17 @@ export function toBeCharCodes(value: string, minCharCode: number, maxCharCode: n
         }
     }
 }
+
+/**
+ * Expect a value to be an email.
+ * @param email The value expected to be an email.
+ * @param errorMessage The optional error message displayed if expectation fails.
+ * @throws {ExpectationError}
+ */
+export function toBeEmail(email: string, errorMessage?: string) {
+    const regex = /[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/
+    const match = email.match(regex);
+    if(match === null || (match[0] !== email)) {
+        throw new ExpectationError(errorMessage);
+    }
+}

test/Expect.spec.ts

@@ -5,8 +5,9 @@ import {
     toBeFalse,
     toBeTrue,
     toExist,
-    toNotExist
-} from './../src';
+    toNotExist,
+    toBeEmail
+} from '../src';
 
 describe('expect', () => {
 
@@ -116,4 +117,44 @@ describe('expect', () => {
             expect(() => toBeCharCodes(String.fromCharCode(64, 90), 65, 90, errorMessage)).toThrow(ExpectationError);
         });
     });
+
+    describe('#toBeEmail', () => {
+        test('should pass if expectation is fulfilled', () => {
+            toBeEmail('email@example.com')
+            toBeEmail('firstname.lastname@example.com')
+            toBeEmail('email@subdomain.example.com')
+            toBeEmail('firstname+lastname@example.com')
+            toBeEmail('email@123.123.123.123')
+            toBeEmail('1234567890@example.com')
+            toBeEmail('email@example-one.com')
+            toBeEmail('_______@example.com')
+            toBeEmail('email@example.web')
+            toBeEmail('email@example.name')
+            toBeEmail('email@example.museum')
+            toBeEmail('email@example.co.jp')
+            toBeEmail('firstname-lastname@example.com')
+        })
+
+        test('should fail if expectation is unfulfilled', () => {
+            expect(() => toBeEmail('email@[123.123.123.123]')).toThrow(ExpectationError);
+            expect(() => toBeEmail('"email"@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('plainaddress')).toThrow(ExpectationError);
+            expect(() => toBeEmail('#@%^%#$@#$@#.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('Joe Smith <email@example.com>')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email.example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email@example@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('.email@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email.@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email..email@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email@example.com (Joe Smith)')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email@example')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email@-example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('email@example..com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('Abc..123@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('”(),:;<>[\]@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('just”not”right@example.com')).toThrow(ExpectationError);
+            expect(() => toBeEmail('this\ is"really"not\allowed@example.com')).toThrow(ExpectationError);
+        })
+    })
 });