Add is email

src/is/types.js

@@ -125,6 +125,16 @@ export function isWindowObject(value) {
     return value != null && typeof value === 'object' && 'setInterval' in value;
 }
 
+/**
+ * Returns whether a given value is an email
+ * @param {*} value the value to check
+ */
+export function isEmail(value) {
+    /* eslint-disable-next-line no-useless-escape */
+    const re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
+    return re.test(String(value).toLowerCase());
+}
+
 export default {
     object: isObject,
     array: isArray,
@@ -142,4 +152,5 @@ export default {
     regexp: isRegexp,
     undefined: isUndefined,
     windowObject: isWindowObject,
+    email: isEmail,
 };

test/is/types.test.js

@@ -197,3 +197,15 @@ describe('isWindowObject', () => {
     });
     testFalsyWithNullable(is.windowObject);
 });
+
+describe('isEmail', () => {
+    test('returns true', () => {
+        expect(is.email('very.common@example.com')).toBeTruthy();
+        expect(is.email('other.email-with-hyphen@example.com')).toBeTruthy();
+        expect(is.email('user.name+tag+sorting@example.com')).toBeTruthy();
+    });
+    test('returns false', () => {
+        expect(is.email('john..doe@example.com')).toBeFalsy();
+    });
+    testFalsyWithNullable(is.email);
+});