fix: handle invalid package uploads

src/Admin/FileImportController.php

@@ -49,7 +49,23 @@ final class FileImportController {
 			throw new \RuntimeException( 'The package file could not be read.' );
 		}
 
+		try {
 			$package = $this->transport->import( $contents );
+		} catch ( \InvalidArgumentException $exception ) {
+			$this->logger->warning(
+				'Rejected imported content package.',
+				array(
+					'error' => $exception->getMessage(),
+				)
+			);
+
+			$this->redirectToDashboard(
+				array(
+					'wpcs_import_error' => $exception->getMessage(),
+				)
+			);
+			return;
+		}
 
 		$this->logger->info(
 			'Validated imported content package.',
@@ -59,9 +75,20 @@ final class FileImportController {
 			)
 		);
 
+		$this->redirectToDashboard(
+			array(
+				'wpcs_imported' => '1',
+			)
+		);
+	}
+
+	/**
+	 * @param array<string, string> $args Redirect query args.
+	 */
+	private function redirectToDashboard( array $args ): void {
 		wp_safe_redirect(
 			add_query_arg(
-				array( 'wpcs_imported' => '1' ),
+				$args,
 				admin_url( 'admin.php?page=wp-content-sync' )
 			)
 		);

templates/admin/dashboard.php

@@ -26,6 +26,20 @@ if ( ! defined( 'ABSPATH' ) ) {
 		</p>
 	</div>
 
+	<?php // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Displays redirect status only. ?>
+	<?php if ( isset( $_GET['wpcs_import_error'] ) ) : ?>
+		<div class="notice notice-error">
+			<p><?php echo esc_html( sanitize_text_field( wp_unslash( $_GET['wpcs_import_error'] ) ) ); ?></p>
+		</div>
+	<?php endif; ?>
+
+	<?php // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Displays redirect status only. ?>
+	<?php if ( isset( $_GET['wpcs_imported'] ) ) : ?>
+		<div class="notice notice-success">
+			<p><?php echo esc_html__( 'The package JSON file was validated successfully.', 'wp-content-sync' ); ?></p>
+		</div>
+	<?php endif; ?>
+
 	<h2><?php echo esc_html__( 'Current Defaults', 'wp-content-sync' ); ?></h2>
 	<table class="widefat striped">
 		<tbody>

tests/Unit/Admin/DashboardTemplateTest.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace WPContentSync\Tests\Unit\Admin;
+
+use PHPUnit\Framework\TestCase;
+use WPContentSync\Settings\Settings;
+
+class DashboardTemplateTest extends TestCase {
+	protected function tearDown(): void {
+		$_GET = array();
+
+		parent::tearDown();
+	}
+
+	public function test_it_renders_import_error_notices(): void {
+		$_GET['wpcs_import_error'] = 'The selected file is not valid JSON.';
+
+		$output = $this->renderDashboard();
+
+		self::assertStringContainsString( 'notice-error', $output );
+		self::assertStringContainsString( 'The selected file is not valid JSON.', $output );
+	}
+
+	public function test_it_renders_import_success_notices(): void {
+		$_GET['wpcs_imported'] = '1';
+
+		$output = $this->renderDashboard();
+
+		self::assertStringContainsString( 'notice-success', $output );
+		self::assertStringContainsString( 'The package JSON file was validated successfully.', $output );
+	}
+
+	private function renderDashboard(): string {
+		$settings = Settings::fromArray( array() );
+
+		ob_start();
+		include WPCS_PLUGIN_DIR . 'templates/admin/dashboard.php';
+
+		return (string) ob_get_clean();
+	}
+}

tests/Unit/Admin/FileImportControllerTest.php

@@ -82,6 +82,20 @@ class FileImportControllerTest extends TestCase {
 		self::assertStringContainsString( 'wpcs_imported=1', $GLOBALS['wpcs_redirect_location'] );
 	}
 
+	public function test_it_redirects_with_error_for_invalid_uploaded_packages(): void {
+		$file = $this->createTemporaryPackageFile( '{"schema_version":' );
+
+		$_FILES['wpcs_package_file'] = array(
+			'tmp_name' => $file,
+			'error'    => UPLOAD_ERR_OK,
+		);
+
+		$this->controller()->handleImport();
+
+		self::assertStringContainsString( 'wpcs_import_error=', $GLOBALS['wpcs_redirect_location'] );
+		self::assertStringContainsString( 'not+valid+JSON', $GLOBALS['wpcs_redirect_location'] );
+	}
+
 	private function controller(): FileImportController {
 		return new FileImportController(
 			new JsonFileTransport( new PackageValidator() ),