fix(files_external): ignore unsatisfied optional dependencies

apps/files_external/lib/Controller/StoragesController.php

@@ -140,7 +140,7 @@ protected function validate(StorageConfig $storage) {
 		$backend = $storage->getBackend();
 		/** @var AuthMechanism */
 		$authMechanism = $storage->getAuthMechanism();
-		if ($backend->checkDependencies()) {
+		if ($backend->checkRequiredDependencies()) {
 			// invalid backend
 			return new DataResponse(
 				[

apps/files_external/lib/Lib/DependencyTrait.php

@@ -13,11 +13,23 @@
 trait DependencyTrait {
 
 	/**
-	 * Check if object is valid for use
+	 * Check if object has unsatisfied required or optional dependencies
 	 *
 	 * @return MissingDependency[] Unsatisfied dependencies
 	 */
 	public function checkDependencies() {
 		return []; // no dependencies by default
 	}
+
+	/**
+	 * Check if object has unsatisfied required dependencies
+	 *
+	 * @return MissingDependency[] Unsatisfied required dependencies
+	 */
+	public function checkRequiredDependencies() {
+		return array_filter(
+			$this->checkDependencies(),
+			fn (MissingDependency $dependency) => !$dependency->isOptional()
+		);
+	}
 }

apps/files_external/lib/Service/BackendService.php

@@ -13,7 +13,6 @@
 use OCA\Files_External\Lib\Backend\Backend;
 use OCA\Files_External\Lib\Config\IAuthMechanismProvider;
 use OCA\Files_External\Lib\Config\IBackendProvider;
-use OCA\Files_External\Lib\MissingDependency;
 use OCP\EventDispatcher\GenericEvent;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\IAppConfig;
@@ -188,10 +187,7 @@ public function getBackends() {
 	 * @return Backend[]
 	 */
 	public function getAvailableBackends() {
-		return array_filter($this->getBackends(), function ($backend) {
-			$missing = array_filter($backend->checkDependencies(), fn (MissingDependency $dependency) => !$dependency->isOptional());
-			return count($missing) === 0;
-		});
+		return array_filter($this->getBackends(), fn (Backend $backend) => !$backend->checkRequiredDependencies());
 	}
 
 	/**

apps/files_external/tests/Service/BackendServiceTest.php

@@ -175,11 +175,11 @@ public function testGetAvailableBackends(): void {
 
 		$backendAvailable = $this->getBackendMock('\Backend\Available');
 		$backendAvailable->expects($this->once())
-			->method('checkDependencies')
+			->method('checkRequiredDependencies')
 			->willReturn([]);
 		$backendNotAvailable = $this->getBackendMock('\Backend\NotAvailable');
 		$backendNotAvailable->expects($this->once())
-			->method('checkDependencies')
+			->method('checkRequiredDependencies')
 			->willReturn([
 				$this->getMockBuilder('\OCA\Files_External\Lib\MissingDependency')
 					->disableOriginalConstructor()