fix(templates): handle upload errors properly

cypress/e2e/templates.spec.js

@@ -58,6 +58,62 @@ describe('Global templates', function() {
 		})
 	})
 
+	it('Surfaces the reason the server rejected the upload', function() {
+		cy.intercept('POST', '**/richdocuments/template', {
+			statusCode: 400,
+			body: { data: { message: 'File is too big' } },
+		}).as('templateUploadRequest')
+
+		cy.uploadSystemTemplate({
+			fixturePath: 'templates/presentation.otp',
+			fileName: 'errortemplate.otp',
+			mimeType: 'application/vnd.oasis.opendocument.presentation-template',
+		})
+
+		cy.wait('@templateUploadRequest')
+		cy.contains('[role="alert"]', 'File is too big').should('be.visible')
+		cy.get('.template-btn[data-cy-template-btn-name="errortemplate"]').should('not.exist')
+	})
+
+	it('Reports a failure even when the error response carries no message', function() {
+		cy.intercept('POST', '**/richdocuments/template', {
+			statusCode: 500,
+			body: '',
+		}).as('templateUploadRequest')
+
+		cy.uploadSystemTemplate({
+			fixturePath: 'templates/presentation.otp',
+			fileName: 'errortemplate.otp',
+			mimeType: 'application/vnd.oasis.opendocument.presentation-template',
+		})
+
+		cy.wait('@templateUploadRequest')
+		cy.contains('[role="alert"]', 'Failed to upload the file').should('be.visible')
+		cy.get('.template-btn[data-cy-template-btn-name="errortemplate"]').should('not.exist')
+	})
+
+	it('Can be picked a second time after its upload failed', function() {
+		const template = {
+			fixturePath: 'templates/presentation.otp',
+			fileName: 'errortemplate.otp',
+			mimeType: 'application/vnd.oasis.opendocument.presentation-template',
+		}
+
+		cy.intercept('POST', '**/richdocuments/template', {
+			statusCode: 400,
+			body: { data: { message: 'Failed to upload the file' } },
+		}).as('templateUploadRequest')
+
+		cy.uploadSystemTemplate(template)
+		cy.wait('@templateUploadRequest')
+
+		// Picking the same file only fires a change event if the input was reset
+		cy.selectSystemTemplate(template)
+		cy.wait('@templateUploadRequest')
+
+		cy.get('@templateUploadRequest.all').should('have.length', 2)
+	})
+
 	it('Can be created by a user', () => {
 		cy.uploadSystemTemplate({
 			fixturePath: 'templates/presentation.otp',

cypress/support/commands.js

@@ -368,6 +368,14 @@ Cypress.Commands.add('verifyOpen', (filename) => {
 	})
 })
 
+Cypress.Commands.add('selectSystemTemplate', ({ fixturePath, fileName, mimeType }) => {
+	cy.get('.settings-section input[type="file"]').selectFile({
+		contents: `cypress/fixtures/${fixturePath}`,
+		fileName,
+		mimeType,
+	}, { force: true })
+})
+
 Cypress.Commands.add('uploadSystemTemplate', ({ fixturePath, fileName, mimeType }) => {
 	cy.login(new User('admin', 'admin'))
 	cy.visit('/settings/admin/richdocuments')
@@ -376,11 +384,7 @@ Cypress.Commands.add('uploadSystemTemplate', ({ fixturePath, fileName, mimeType
 		.contains('Global Templates')
 		.scrollIntoView()
 
-	cy.get('.settings-section input[type="file"]').selectFile({
-		contents: `cypress/fixtures/${fixturePath}`,
-		fileName,
-		mimeType,
-	}, { force: true })
+	cy.selectSystemTemplate({ fixturePath, fileName, mimeType })
 })
 
 Cypress.Commands.add('submitTemplateFields', (fields) => {

lib/Controller/TemplatesController.php

@@ -101,17 +101,23 @@ public function add() {
 		$files = $this->request->getUploadedFile('files');
 
 		if (!is_null($files)) {
-			$mimeType = !empty($files['type'] ?? '') ? $files['type'] : $this->mimeTypeDetector->detect($files['tmp_name']);
 			$error = $files['error'] ?? 0;
 
 			if ($error !== 0) {
 				$this->logger->error('Failed to get the uploaded file. PHP file upload error code: ' . $error);
+				$message = match ($error) {
+					UPLOAD_ERR_INI_SIZE, UPLOAD_ERR_FORM_SIZE => $this->l10n->t('File is too big'),
+					UPLOAD_ERR_NO_FILE => $this->l10n->t('No file was uploaded'),
+					default => $this->l10n->t('Failed to upload the file'),
+				};
 				return new JSONResponse(
-					['data' => ['message' => $this->l10n->t('Failed to upload the file')]],
+					['data' => ['message' => $message]],
 					Http::STATUS_BAD_REQUEST
 				);
 			}
 
+			$mimeType = !empty($files['type'] ?? '') ? $files['type'] : $this->mimeTypeDetector->detect($files['tmp_name']);
+
 			if (is_uploaded_file($files['tmp_name']) && !Filesystem::isFileBlacklisted($files['tmp_name'])) {
 				if ($files['size'] > $this->maxSize) {
 					return new JSONResponse(

src/components/AdminSettings/GlobalTemplates.vue

@@ -112,17 +112,32 @@ export default {
 
 		async selectFile() {
 			const selectedFile = this.$refs.newTemplateInput?.files[0]
-			const templateAlreadyExists = this.existingTemplates.some((template) => {
-				return template.name === selectedFile.name
-			})
 
-			if (!templateAlreadyExists) {
+			if (!selectedFile) {
+				return
+			}
+
+			try {
+				const templateAlreadyExists = this.existingTemplates.some((template) => {
+					return template.name === selectedFile.name
+				})
+
+				if (templateAlreadyExists) {
+					showError(t('richdocuments', 'Template "{name}" already exists', { name: selectedFile.name }))
+					return
+				}
+
 				const template = await this.uploadTemplate(selectedFile)
 
+				if (template === null) {
+					return
+				}
+
 				this.existingTemplates.push(template)
 				showSuccess(t('richdocuments', 'Uploaded template "{name}"', { name: template.name }))
-			} else {
-				showError(t('richdocuments', 'Template "{name}" already exists', { name: selectedFile.name }))
+			} finally {
+				// Allow selecting the same file again after a failed upload
+				this.$refs.newTemplateInput.value = ''
 			}
 		},
 
@@ -132,18 +147,20 @@ export default {
 
 			formData.append('files', file)
 
-			let res = null
 			try {
-				res = await axios.post(url, formData, {
+				const res = await axios.post(url, formData, {
 					headers: {
 						'Content-Type': 'multipart/form-data',
 					},
 				})
+
+				return res.data.data
 			} catch (error) {
-				showError(error.response.data.data.message)
-			}
+				showError(error.response?.data?.data?.message
+					?? t('richdocuments', 'Failed to upload the file'))
 
-			return res.data.data
+				return null
+			}
 		},
 
 		async deleteTemplate(templateId) {

tests/lib/Controller/TemplatesControllerTest.php

@@ -0,0 +1,137 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace Tests\Richdocuments\Controller;
+
+use OCA\Richdocuments\Controller\TemplatesController;
+use OCA\Richdocuments\TemplateManager;
+use OCP\AppFramework\Http;
+use OCP\Files\IMimeTypeDetector;
+use OCP\IL10N;
+use OCP\IPreview;
+use OCP\IRequest;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+class TemplatesControllerTest extends TestCase {
+	private IRequest $request;
+	private IL10N $l10n;
+	private TemplateManager $manager;
+	private IMimeTypeDetector $mimeTypeDetector;
+	private LoggerInterface $logger;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->request = $this->createMock(IRequest::class);
+		$this->l10n = $this->createMock(IL10N::class);
+		$this->manager = $this->createMock(TemplateManager::class);
+		$this->mimeTypeDetector = $this->createMock(IMimeTypeDetector::class);
+		$this->logger = $this->createMock(LoggerInterface::class);
+
+		$this->l10n->method('t')->willReturnArgument(0);
+	}
+
+	private function makeController(): TemplatesController {
+		return new TemplatesController(
+			'richdocuments',
+			$this->request,
+			$this->l10n,
+			$this->manager,
+			$this->createMock(IPreview::class),
+			$this->mimeTypeDetector,
+			$this->logger,
+		);
+	}
+
+	private function givenUploadedFile(?array $file): void {
+		$this->request->method('getUploadedFile')->with('files')->willReturn($file);
+	}
+
+	private function getMessage(Http\Response $response): ?string {
+		return $response->getData()['data']['message'] ?? null;
+	}
+
+	public static function uploadErrorProvider(): array {
+		return [
+			'exceeds upload_max_filesize' => [UPLOAD_ERR_INI_SIZE, 'File is too big'],
+			'exceeds MAX_FILE_SIZE' => [UPLOAD_ERR_FORM_SIZE, 'File is too big'],
+			'no file submitted' => [UPLOAD_ERR_NO_FILE, 'No file was uploaded'],
+			'partial upload' => [UPLOAD_ERR_PARTIAL, 'Failed to upload the file'],
+			'missing temp dir' => [UPLOAD_ERR_NO_TMP_DIR, 'Failed to upload the file'],
+			'write failed' => [UPLOAD_ERR_CANT_WRITE, 'Failed to upload the file'],
+			'stopped by extension' => [UPLOAD_ERR_EXTENSION, 'Failed to upload the file'],
+		];
+	}
+
+	/**
+	 * @dataProvider uploadErrorProvider
+	 */
+	public function testAddReportsUploadErrors(int $error, string $expectedMessage): void {
+		$this->givenUploadedFile([
+			'name' => 'template.otp',
+			'type' => '',
+			'tmp_name' => '',
+			'error' => $error,
+			'size' => 0,
+		]);
+		$this->logger->expects($this->once())->method('error');
+
+		$response = $this->makeController()->add();
+
+		$this->assertSame(Http::STATUS_BAD_REQUEST, $response->getStatus());
+		$this->assertSame($expectedMessage, $this->getMessage($response));
+	}
+
+	/**
+	 * A failed upload leaves tmp_name empty, and detecting the mime type of an empty path
+	 * raises a ValueError that surfaces as a 500 instead of the upload error.
+	 *
+	 * @dataProvider uploadErrorProvider
+	 */
+	public function testAddDoesNotDetectMimeTypeOfAFailedUpload(int $error): void {
+		$this->givenUploadedFile([
+			'name' => 'template.otp',
+			'type' => '',
+			'tmp_name' => '',
+			'error' => $error,
+			'size' => 0,
+		]);
+		$this->mimeTypeDetector->expects($this->never())->method('detect');
+
+		$this->makeController()->add();
+	}
+
+	public function testAddRejectsAMissingUpload(): void {
+		$this->givenUploadedFile(null);
+		$this->mimeTypeDetector->expects($this->never())->method('detect');
+		$this->manager->expects($this->never())->method('add');
+
+		$response = $this->makeController()->add();
+
+		$this->assertSame(Http::STATUS_BAD_REQUEST, $response->getStatus());
+		$this->assertSame('Invalid file provided', $this->getMessage($response));
+	}
+
+	public function testAddRejectsAFileThatWasNotUploaded(): void {
+		$this->givenUploadedFile([
+			'name' => 'template.otp',
+			'type' => 'application/vnd.oasis.opendocument.presentation-template',
+			'tmp_name' => '/etc/passwd',
+			'error' => UPLOAD_ERR_OK,
+			'size' => 1024,
+		]);
+		$this->manager->expects($this->never())->method('add');
+
+		$response = $this->makeController()->add();
+
+		$this->assertSame(Http::STATUS_BAD_REQUEST, $response->getStatus());
+		$this->assertSame('Invalid file provided', $this->getMessage($response));
+	}
+}