fix app provider new file action and improve app provider error codes (#2210)

Author: wkloucek

changelog/unreleased/app-provider-new-file.md

@@ -0,0 +1,8 @@
+Change: Fix app provider new file creation and improved error codes
+
+We've fixed the behavior for the app provider when creating new files.
+Previously the app provider would overwrite already existing files when creating a new file, this is now handled and prevented.
+The new file endpoint accepted a path to a file, but this does not work for spaces. Therefore we now use the resource id of the folder where the file should be created and a filename to create the new file.
+Also the app provider returns more useful error codes in a lot of cases.
+
+https://github.com/cs3org/reva/pull/2210

internal/grpc/services/gateway/appprovider.go

@@ -242,7 +242,7 @@ func (s *svc) findAppProvider(ctx context.Context, ri *storageprovider.ResourceI
 
 		// we did not find a default provider
 		if res.Status.Code == rpc.Code_CODE_NOT_FOUND {
-			err := errtypes.NotFound(fmt.Sprintf("gateway: default app rovider for mime type:%s not found", ri.MimeType))
+			err := errtypes.NotFound(fmt.Sprintf("gateway: default app provider for mime type:%s not found", ri.MimeType))
 			return nil, err
 		}
 
@@ -285,7 +285,10 @@ func (s *svc) findAppProvider(ctx context.Context, ri *storageprovider.ResourceI
 	}
 	res.Providers = filteredProviders
 
-	// if we only have one app provider we verify that it matches the requested app name
+	if len(res.Providers) == 0 {
+		return nil, errtypes.NotFound(fmt.Sprintf("app '%s' not found", app))
+	}
+
 	if len(res.Providers) == 1 {
 		return res.Providers[0], nil
 	}