[12.x] create new @hasStack Blade directive

src/Illuminate/View/Compilers/Concerns/CompilesConditionals.php

@@ -137,6 +137,17 @@ protected function compileHasSection($expression)
         return "<?php if (! empty(trim(\$__env->yieldContent{$expression}))): ?>";
     }
 
+    /**
+     * Compile the has-stack statements into valid PHP.
+     *
+     * @param  string  $expression
+     * @return string
+     */
+    protected function compileHasStack($expression)
+    {
+        return "<?php if (! \$__env->isStackEmpty{$expression}): ?>";
+    }
+
     /**
      * Compile the section-missing statements into valid PHP.
      *

src/Illuminate/View/Concerns/ManagesStacks.php

@@ -148,7 +148,7 @@ protected function extendPrepend($section, $content)
      */
     public function yieldPushContent($section, $default = '')
     {
-        if (! isset($this->pushes[$section]) && ! isset($this->prepends[$section])) {
+        if ($this->isStackEmpty($section)) {
             return $default;
         }
 
@@ -165,6 +165,14 @@ public function yieldPushContent($section, $default = '')
         return $output;
     }
 
+    /**
+     * Determine if the stack has any content in it.
+     */
+    public function isStackEmpty(string $section): bool
+    {
+        return ! isset($this->pushes[$section]) && ! isset($this->prepends[$section]);
+    }
+
     /**
      * Flush all of the stacks.
      *

tests/View/Blade/BladeHasStackTest.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Illuminate\Tests\View\Blade;
+
+class BladeHasStackTest extends AbstractBladeTestCase
+{
+    public function testHasStackStatementsAreCompiled()
+    {
+        $string = '@hasStack("stack")
+breeze
+@endif';
+        $expected = '<?php if (! $__env->isStackEmpty("stack")): ?>
+breeze
+<?php endif; ?>';
+        $this->assertEquals($expected, $this->compiler->compileString($string));
+    }
+}

tests/View/Concerns/ManagesStacksTest.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Illuminate\Tests\View\Concerns;
+
+use Illuminate\View\Concerns\ManagesStacks;
+use PHPUnit\Framework\TestCase;
+
+class ManagesStacksTest extends TestCase
+{
+    public function testStackIsEmpty()
+    {
+        $this->assertTrue((new FakeViewFactory)->isStackEmpty('my-stack'));
+    }
+
+    public function testStackIsNotEmptyWithPushedContent()
+    {
+        $object = new FakeViewFactory;
+        $object->startPush('my-stack', 'some pushed content');
+
+        $this->assertFalse($object->isStackEmpty('my-stack'));
+    }
+
+    public function testStackIsNotEmptyWithPrependedContent()
+    {
+        $object = new FakeViewFactory;
+        $object->startPrepend('my-stack', 'some prepended content');
+
+        $this->assertFalse($object->isStackEmpty('my-stack'));
+    }
+}
+
+class FakeViewFactory
+{
+    use ManagesStacks;
+
+    protected int $renderCount = 0;
+}