Add tests

Author: Ayesh

tests/ArrayFindTest.php

@@ -7,8 +7,46 @@
 class ArrayFindTest extends TestCase {
 
     public function testArrayFind() {
+        $array1 = [
+            "a" => 1,
+            "b" => 2,
+            "c" => 3,
+            "d" => 4,
+            "e" => 5,
+        ];
+
+        $array2 = [
+            1, 2, 3, 4, 5,
+        ];
+
+        $evenFunction = static function($input) {
+            return $input % 2 === 0;
+        };
+
         self::assertSame(array_find(['apple', 'banana'], static function($value, $key) {
             return $value === 'banana';
         }), 'banana');
+
+        self::assertSame(2, array_find($array1, $evenFunction));
+
+        self::assertNull(array_find($array2, static function($value) {
+            return $value > 5;
+        }));
+
+        self::assertNull(array_find($array2, static function($value) {
+            return $value > 5;
+        }));
+
+        self::assertNull(array_find([], static function($value) {
+            return true;
+        }));
+
+        self::assertSame(3, array_find($array1, static function($value, $key) {
+            return $key === "c";
+        }));
+
+        self::assertNull(array_find($array1, static function($value) {
+            return false;
+        }));
     }
 }