Added method join and wraps

Author: emsifa

src/Helper.php

@@ -203,4 +203,49 @@ public static function snakeCase(string $value, string $delimiter = '_'): string
 
         return $value;
     }
+
+    /**
+     * Join string[] to string with given $separator and $lastSeparator.
+     *
+     * @param  array        $pieces
+     * @param  string       $separator
+     * @param  string|null  $lastSeparator
+     * @return string
+     */
+    public static function join(array $pieces, string $separator, string $lastSeparator = null): string
+    {
+        if (is_null($lastSeparator)) {
+            $lastSeparator = $separator;
+        }
+
+        $last = array_pop($pieces);
+
+        switch (count($pieces)) {
+            case 0:
+                return $last ?: '';
+            case 1:
+                return $pieces[0] . $lastSeparator . $last;
+            default:
+                return implode($separator, $pieces) . $lastSeparator . $last;
+        }
+    }
+
+    /**
+     * Wrap string[] by given $prefix and $suffix
+     *
+     * @param  array        $strings
+     * @param  string       $prefix
+     * @param  string|null  $suffix
+     * @return array
+     */
+    public static function wraps(array $strings, string $prefix, string $suffix = null): array
+    {
+        if (is_null($suffix)) {
+            $suffix = $prefix;
+        }
+
+        return array_map(function ($str) use ($prefix, $suffix) {
+            return $prefix . $str . $suffix;
+        }, $strings);
+    }
 }

tests/HelperTest.php

@@ -131,4 +131,28 @@ public function testArrayUnset()
             'message' => "lorem ipsum",
         ]);
     }
+
+    public function testJoin()
+    {
+        $pieces0 = [];
+        $pieces1 = [1];
+        $pieces2 = [1, 2];
+        $pieces3 = [1, 2, 3];
+
+        $separator = ', ';
+        $lastSeparator = ', and ';
+
+        $this->assertEquals(Helper::join($pieces0, $separator, $lastSeparator), '');
+        $this->assertEquals(Helper::join($pieces1, $separator, $lastSeparator), '1');
+        $this->assertEquals(Helper::join($pieces2, $separator, $lastSeparator), '1, and 2');
+        $this->assertEquals(Helper::join($pieces3, $separator, $lastSeparator), '1, 2, and 3');
+    }
+
+    public function testWraps()
+    {
+        $inputs = [1, 2, 3];
+
+        $this->assertEquals(Helper::wraps($inputs, '-'), ['-1-', '-2-', '-3-']);
+        $this->assertEquals(Helper::wraps($inputs, '-', '+'), ['-1+', '-2+', '-3+']);
+    }
 }