fix: allow content to be empty when calling Crawler::html() method (#616)

* fix: allow content to be empty when calling Crawler::html() method

* use default value when content is empty

* cast default value as string

* add test when no default value is provided

Author: syl20b

src/DomCrawler/Crawler.php

@@ -229,13 +229,13 @@ public function html(string $default = null): string
                 return $this->webDriver->getPageSource();
             }
 
-            return $this->attr('outerHTML');
+            return $this->attr('outerHTML', (string) $default);
         } catch (\InvalidArgumentException $e) {
             if (null === $default) {
                 throw $e;
             }
 
-            return (string) $default;
+            return $default;
         }
     }
 

tests/DomCrawler/CrawlerTest.php

@@ -242,7 +242,7 @@ public function testChildren(callable $clientFactory): void
             $names[$i] = $c->nodeName();
         });
 
-        $this->assertSame(['h1', 'main', 'p', 'p', 'input', 'p'], $names);
+        $this->assertSame(['h1', 'main', 'p', 'p', 'input', 'p', 'div'], $names);
     }
 
     /**
@@ -385,6 +385,24 @@ public function testHtmlDefault(callable $clientFactory): void
         $this->assertSame('default', $crawler->filter('header')->html('default'));
     }
 
+    /**
+     * @dataProvider clientFactoryProvider
+     */
+    public function testEmptyHtml(callable $clientFactory): void
+    {
+        $crawler = $this->request($clientFactory, '/basic.html');
+        $this->assertEmpty($crawler->filter('.empty')->html(''));
+    }
+
+    /**
+     * @dataProvider clientFactoryProvider
+     */
+    public function testEmptyHtmlWithoutDefault(callable $clientFactory): void
+    {
+        $crawler = $this->request($clientFactory, '/basic.html');
+        $this->assertEmpty($crawler->filter('.empty')->html());
+    }
+
     /**
      * @dataProvider clientFactoryProvider
      */

tests/fixtures/basic.html

@@ -16,5 +16,6 @@ <h1>Main</h1>
     <p class="p-2">P2</p>
     <input name="in" value="test">
     <p class="price" data-old-price="42">36</p>
+    <div class="empty"></div>
 </body>
 </html>