[TwigComponent] Merge data-action when using ComponentAttributes

Author: weaverryan

src/TwigComponent/src/ComponentAttributes.php

@@ -80,7 +80,7 @@ public function defaults(iterable $attributes): self
         }
 
         foreach ($this->attributes as $key => $value) {
-            if (\in_array($key, ['class', 'data-controller'], true) && isset($attributes[$key])) {
+            if (\in_array($key, ['class', 'data-controller', 'data-action'], true) && isset($attributes[$key])) {
                 $attributes[$key] = "{$attributes[$key]} {$value}";
 
                 continue;

src/TwigComponent/tests/Unit/ComponentAttributesTest.php

@@ -146,6 +146,28 @@ public function testCanAddStimulusControllerViaStimulusAttributes(): void
         ], $attributes->all());
     }
 
+    public function testCanAddStimulusActionViaStimulusAttributes(): void
+    {
+        // if PHP less than 8.1, skip
+        if (version_compare(\PHP_VERSION, '8.1.0', '<')) {
+            $this->markTestSkipped('PHP 8.1+ required');
+        }
+
+        $attributes = new ComponentAttributes([
+            'class' => 'foo',
+            'data-action' => 'live#foo',
+        ]);
+
+        $stimulusAttributes = new StimulusAttributes(new Environment(new ArrayLoader()));
+        $stimulusAttributes->addAction('foo', 'barMethod');
+        $attributes = $attributes->defaults([...$stimulusAttributes]);
+
+        $this->assertEquals([
+            'class' => 'foo',
+            'data-action' => 'foo#barMethod live#foo',
+        ], $attributes->all());
+    }
+
     public function testBooleanBehaviour(): void
     {
         $attributes = new ComponentAttributes(['disabled' => true]);