Add is_url function

readme.md

@@ -37,6 +37,7 @@ composer require hedii/helpers
 - [string_contains](#string_contains)
 - [string_finish](#string_finish)
 - [string_random](#string_random)
+- [is_url](#is_url)
 - [class_basename](#class_basename)
 - [is_windows_os](#is_windows_os)
 
@@ -213,6 +214,23 @@ $string = string_random(40);
 
 ---
 
+<a name="is_url"></a>
+#### `is_url(string $string)`
+
+Determine if a string is a valid url.
+
+```php
+is_url('http://example.com');
+
+// true
+
+is_url('tel:+1-111-222-333');
+
+// false
+```
+
+---
+
 <a name="class_basename"></a>
 #### `class_basename(string|object $class)`
 

src/helpers.php

@@ -237,6 +237,19 @@ function string_finish($value, $cap)
     }
 }
 
+if (! function_exists('is_url')) {
+    /**
+     * Determine if a string is a valid url.
+     *
+     * @param string $string
+     * @return bool
+     */
+    function is_url($string)
+    {
+        return (bool) filter_var($string, FILTER_VALIDATE_URL);
+    }
+}
+
 if (! function_exists('class_basename')) {
     /**
      * Get the class "basename" of the given object / class.
@@ -262,4 +275,5 @@ function is_windows_os()
     {
         return strtolower(substr(PHP_OS, 0, 3)) === 'win';
     }
-}
+}
+

tests/HelpersTest.php

@@ -6,6 +6,28 @@ class HelpersTest extends TestCase
 {
     private $string = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.';
 
+    private $validUrls = [
+        'ftp://ftp.is.co.za.example.org/rfc/rfc1808.txt',
+        'gopher://spinaltap.micro.umn.example.edu/00/Weather/California/Los%20Angeles',
+        'http://www.ietf.org/rfc/rfc2396.txt',
+        'http://www.math.uio.no.example.net/faq/compression-faq/part1.html',
+        'https://www.youtube.com/watch?v=6FOUqQt3Kg0',
+        'ldap://[2001:db8::7]/c=GB?objectClass?one',
+        'mailto:John.Doe@example.com',
+        'mailto:mduerst@ifi.unizh.example.gov',
+        'news:comp.infosystems.www.servers.unix',
+        'news:comp.infosystems.www.servers.unix',
+        'telnet://192.0.2.16:80/',
+        'telnet://melvyl.ucop.example.edu/'
+    ];
+
+    private $invalidUrls = [
+        'example.com',
+        'http:/example.com/',
+        'tel:+1-816-555-1212',
+        'urn:oasis:names:specification:docbook:dtd:xml:4.1.2'
+    ];
+
     public function setUp()
     {
         parent::setUp();
@@ -101,6 +123,19 @@ public function test_it_should_have_string_random_helper()
         $this->assertEquals(16, strlen(string_random(16)));
     }
 
+    public function test_it_should_have_is_url_helper()
+    {
+        foreach ($this->validUrls as $url) {
+            $this->assertTrue(is_url($url));
+            $this->assertInternalType('boolean', is_url($url));
+        }
+
+        foreach ($this->invalidUrls as $url) {
+            $this->assertFalse(is_url($url));
+            $this->assertInternalType('boolean', is_url($url));
+        }
+    }
+
     public function test_it_should_have_class_basename_helper()
     {
         $this->assertEquals('HelpersTest', class_basename($this));