Make ::clone work with the help of the MemoryContentStorageHandler

src/Content/ContentStorageHandler.php

@@ -128,6 +128,30 @@ public function ensure(VersionId $versionId, Language $language): bool
 	 */
 	abstract public function exists(VersionId $versionId, Language $language): bool;
 
+	/**
+	 * Creates a new storage instance with all the versions
+	 * from the given storage instance.
+	 */
+	public static function from(self $fromStorage): static
+	{
+		$toStorage = new static(
+			model: $fromStorage->model()
+		);
+
+		// copy all versions from the given storage instance
+		// and add them to the new storage instance.
+		foreach ($fromStorage->all() as $versionId => $language) {
+			$toStorage->create($versionId, $language, $fromStorage->read($versionId, $language));
+		}
+
+		return $toStorage;
+	}
+
+	public function model(): ModelWithContent
+	{
+		return $this->model;
+	}
+
 	/**
 	 * Returns the modification timestamp of a version if it exists
 	 */

src/Content/LabPage.php

@@ -14,6 +14,18 @@
  */
 class LabPage extends Page
 {
+	/**
+	 * Creates a new instance with the same
+	 * initial properties
+	 *
+	 * @todo eventually refactor without need of propertyData
+	 */
+	public function clone(array $props = []): static
+	{
+		$this->storage = MemoryContentStorageHandler::from($this->storage);
+		return parent::clone($props);
+	}
+
 	/**
 	 * Returns the content for the default version and given language code
 	 */
@@ -38,8 +50,9 @@ public function save(
 		string|null $languageCode = null,
 		bool $overwrite = false
 	): static {
-		$this->version()->save($data, $languageCode ?? 'current', $overwrite);
-		return $this;
+		$clone = $this->clone();
+		$clone->version()->save($data, $languageCode ?? 'current', $overwrite);
+		return $clone;
 	}
 
 	/**
@@ -49,8 +62,9 @@ protected function saveContent(
 		array|null $data = null,
 		bool $overwrite = false
 	): static {
-		$this->version()->save($data, 'current', $overwrite);
-		return $this;
+		$clone = $this->clone();
+		$clone->version()->save($data, 'current', $overwrite);
+		return $clone;
 	}
 
 	/**
@@ -61,8 +75,9 @@ protected function saveTranslation(
 		string|null $languageCode = null,
 		bool $overwrite = false
 	): static {
-		$this->version()->save($data, $languageCode ?? 'current', $overwrite);
-		return $this;
+		$clone = $this->clone();
+		$clone->version()->save($data, $languageCode ?? 'current', $overwrite);
+		return $clone;
 	}
 
 	/**
@@ -143,7 +158,7 @@ public function translations(): Translations
 	 */
 	public function writeContent(array $data, string|null $languageCode = null): bool
 	{
-		$this->version()->save($data, $languageCode ?? 'default', true);
+		$this->clone()->version()->save($data, $languageCode ?? 'default', true);
 		return true;
 	}
 }

tests/Content/LabPageTest.php

@@ -234,4 +234,74 @@ public function testTranslationsSingleLanguage()
 		$this->assertCount(1, $translations);
 		$this->assertSame($content, $translations->first()->content());
 	}
+
+	public function testUpdateMultiLanguage()
+	{
+		$this->setUpMultiLanguage();
+
+		$page = new LabPage([
+			'slug'     => 'test',
+			'template' => 'article'
+		]);
+
+		// make sure to be authenticated
+		$this->app->impersonate('kirby');
+
+		// write something to the content file to make sure it
+		// can be read from disk for the test.
+		Data::write($page->root() . '/article.en.txt', $en = [
+			'title' => 'Test English'
+		]);
+
+		Data::write($page->root() . '/article.de.txt', $de = [
+			'title' => 'Test Deutsch'
+		]);
+
+		$updatedPage = $page->update([
+			'title' => 'Updated Test English'
+		], 'en');
+
+		$updatedPage = $page->update([
+			'title' => 'Updated Test Deutsch'
+		], 'de');
+
+		// check if the old version is still the same
+		$this->assertSame('Test English', $page->title()->value());
+
+		$this->assertSame('Updated Test English', $updatedPage->title()->value());
+		$this->assertSame('Updated Test English', $updatedPage->content('en')->title()->value());
+		$this->assertSame('Updated Test English', Data::read($updatedPage->root() . '/article.en.txt')['title']);
+
+		$this->assertSame('Updated Test Deutsch', $updatedPage->content('de')->title()->value());
+		$this->assertSame('Updated Test Deutsch', Data::read($updatedPage->root() . '/article.de.txt')['title']);
+	}
+
+	public function testUpdateSingleLanguage()
+	{
+		$this->setUpSingleLanguage();
+
+		$page = new LabPage([
+			'slug'     => 'test',
+			'template' => 'article'
+		]);
+
+		// make sure to be authenticated
+		$this->app->impersonate('kirby');
+
+		// write something to the content file to make sure it
+		// can be read from disk for the test.
+		Data::write($page->root() . '/article.txt', $content = [
+			'title' => 'Test'
+		]);
+
+		$updatedPage = $page->update([
+			'title' => 'Updated title'
+		]);
+
+		// check if the old version is still the same
+		$this->assertSame('Test', $page->title()->value());
+
+		$this->assertSame('Updated title', $updatedPage->title()->value());
+		$this->assertSame('Updated title', Data::read($updatedPage->root() . '/article.txt')['title']);
+	}
 }