[11.x] add lazy default to when helper (#52747)

* add lazy default to when helper

* Update helpers.php

---------

Co-authored-by: Taylor Otwell <[email protected]>

src/Illuminate/Collections/helpers.php

@@ -239,18 +239,19 @@ function value($value, ...$args)
 
 if (! function_exists('when')) {
     /**
-     * Output a value if the given condition is true.
+     * Return a value if the given condition is true.
      *
      * @param  mixed  $condition
-     * @param  \Closure|mixed  $output
+     * @param  \Closure|mixed  $value
+     * @param  \Closure|mixed  $default
      * @return mixed
      */
-    function when($condition, $output)
+    function when($condition, $value, $default = null)
     {
         if ($condition) {
-            return value($output);
+            return value($value, $condition);
         }
 
-        return null;
+        return value($default, $condition);
     }
 }

tests/Support/SupportHelpersTest.php

@@ -103,15 +103,23 @@ public function testClassBasename()
     public function testWhen()
     {
         $this->assertEquals('Hello', when(true, 'Hello'));
-        $this->assertEquals(null, when(false, 'Hello'));
+        $this->assertNull(when(false, 'Hello'));
         $this->assertEquals('There', when(1 === 1, 'There')); // strict types
         $this->assertEquals('There', when(1 == '1', 'There')); // loose types
-        $this->assertEquals(null, when(1 == 2, 'There'));
-        $this->assertEquals(null, when('1', fn () => null));
-        $this->assertEquals(null, when(0, fn () => null));
+        $this->assertNull(when(1 == 2, 'There'));
+        $this->assertNull(when('1', fn () => null));
+        $this->assertNull(when(0, fn () => null));
         $this->assertEquals('True', when([1, 2, 3, 4], 'True')); // Array
-        $this->assertEquals(null, when([], 'True')); // Empty Array = Falsy
+        $this->assertNull(when([], 'True')); // Empty Array = Falsy
         $this->assertEquals('True', when(new StdClass, fn () => 'True')); // Object
+        $this->assertEquals('World', when(false, 'Hello', 'World'));
+        $this->assertEquals('World', when(1 === 0, 'Hello', 'World')); // strict types
+        $this->assertEquals('World', when(1 == '0', 'Hello', 'World')); // loose types
+        $this->assertNull(when('', fn () => 'There', fn () => null));
+        $this->assertNull(when(0, fn () => 'There', fn () => null));
+        $this->assertEquals('False', when([], 'True', 'False'));  // Empty Array = Falsy
+        $this->assertTrue(when(true, fn ($value) => $value, fn ($value) => ! $value)); // lazy evaluation
+        $this->assertTrue(when(false, fn ($value) => $value, fn ($value) => ! $value)); // lazy evaluation
     }
 
     public function testFilled()