[12.x] Add Stringable::doesntContain() to match API symmetry (#57279)

* Add Stringable::doesntContain() method

This adds the missing doesntContain() method to the Stringable class
to provide symmetry with the contains() method. The method proxies to
the existing Str::doesntContain() implementation.

* Add tests for Stringable::doesntContain() method

Tests cover all parameter combinations including arrays, collections,
case sensitivity, and edge cases. All tests pass successfully.

Author: michaelcontento

src/Illuminate/Support/Stringable.php

@@ -222,6 +222,18 @@ public function containsAll($needles, $ignoreCase = false)
         return Str::containsAll($this->value, $needles, $ignoreCase);
     }
 
+    /**
+     * Determine if a given string doesn't contain a given substring.
+     *
+     * @param  string|iterable<string>  $needles
+     * @param  bool  $ignoreCase
+     * @return bool
+     */
+    public function doesntContain($needles, $ignoreCase = false)
+    {
+        return Str::doesntContain($this->value, $needles, $ignoreCase);
+    }
+
     /**
      * Convert the case of a string.
      *

tests/Support/SupportStringableTest.php

@@ -848,6 +848,19 @@ public function testContainsAll()
         $this->assertFalse($this->stringable('taylor otwell')->containsAll(['taylor', 'xxx']));
     }
 
+    public function testDoesntContain()
+    {
+        $this->assertTrue($this->stringable('taylor')->doesntContain('xxx'));
+        $this->assertTrue($this->stringable('taylor')->doesntContain(['xxx']));
+        $this->assertTrue($this->stringable('taylor')->doesntContain(['xxx', 'yyy']));
+        $this->assertTrue($this->stringable('taylor')->doesntContain(collect(['xxx', 'yyy'])));
+        $this->assertTrue($this->stringable('taylor')->doesntContain(''));
+        $this->assertFalse($this->stringable('taylor')->doesntContain('ylo'));
+        $this->assertFalse($this->stringable('taylor')->doesntContain('taylor'));
+        $this->assertFalse($this->stringable('taylor')->doesntContain(['xxx', 'ylo']));
+        $this->assertFalse($this->stringable('taylor')->doesntContain(['LOR'], true));
+    }
+
     public function testParseCallback()
     {
         $this->assertEquals(['Class', 'method'], $this->stringable('Class@method')->parseCallback('foo'));