ECTO-2761 - fix client exception body parsing

src/Exception/ExtensionStoreApiException.php

@@ -17,14 +17,9 @@ public function __construct(ClientException $exception)
     {
         parent::__construct($exception);
 
-        try {
-            $data = json_decode($exception->getResponse()->getBody()->getContents(), true, 512, \JSON_THROW_ON_ERROR);
-        } catch (\JsonException) {
-        }
+        $data = $this->getData($exception);
         $this->apiCode = $data['code'] ?? '';
         $this->description = $data['description'] ?? '';
-        $this->title = $data['title'] ?? '';
-        $this->documentationLink = $data['documentationLink'] ?? '';
     }
 
     public function getErrors(bool $withTrace = false): \Generator
@@ -38,4 +33,27 @@ public function getErrors(bool $withTrace = false): \Generator
             ];
         }
     }
+
+    /**
+     * @return array<array-key, mixed>
+     */
+    private function getData(ClientException $exception): array
+    {
+        $body = $exception->getResponse()->getBody();
+
+        // The parent constructor already read the body to its end and left the stream at EOF,
+        // so reading it again without rewinding yields an empty string.
+        if ($body->isSeekable()) {
+            $body->rewind();
+        }
+
+        try {
+            $data = json_decode($body->getContents(), true, 512, \JSON_THROW_ON_ERROR);
+        } catch (\JsonException) {
+            return [];
+        }
+
+        // A body may be valid JSON without being an object, e.g. a bare string or number.
+        return \is_array($data) ? $data : [];
+    }
 }

tests/Exception/ExtensionStoreApiExceptionTest.php

@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SwagExtensionStore\Tests\Exception;
+
+use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Psr7\NoSeekStream;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\Psr7\Response;
+use GuzzleHttp\Psr7\Utils;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+use Shopware\Core\Framework\Log\Package;
+use SwagExtensionStore\Exception\ExtensionStoreApiException;
+
+#[Package('checkout')]
+class ExtensionStoreApiExceptionTest extends TestCase
+{
+    public function testErrorExposesTheCompleteStoreApiErrorBody(): void
+    {
+        $exception = new ExtensionStoreApiException($this->createClientException((string) json_encode([
+            'code' => 'STORE__EXTENSION_NOT_PURCHASABLE',
+            'title' => 'Extension cannot be purchased',
+            'description' => 'The extension is not available for your shop.',
+            'documentationLink' => 'https://docs.shopware.com/store-error',
+        ], \JSON_THROW_ON_ERROR)));
+
+        $error = $this->firstError($exception);
+
+        static::assertSame('STORE__EXTENSION_NOT_PURCHASABLE', $error['apiCode']);
+        static::assertSame('Extension cannot be purchased', $error['title']);
+        static::assertSame('The extension is not available for your shop.', $error['description']);
+        static::assertSame('The extension is not available for your shop.', $error['detail']);
+        static::assertIsArray($error['meta']);
+        static::assertSame('https://docs.shopware.com/store-error', $error['meta']['documentationLink']);
+    }
+
+    #[DataProvider('unusableBodyProvider')]
+    public function testErrorFallsBackToEmptyValuesOnAnUnusableBody(string $body): void
+    {
+        $exception = new ExtensionStoreApiException($this->createClientException($body));
+
+        $error = $this->firstError($exception);
+
+        static::assertSame('', $error['apiCode']);
+        static::assertSame('', $error['title']);
+        static::assertSame('', $error['description']);
+        static::assertSame('Store is not reachable', $error['detail']);
+        static::assertIsArray($error['meta']);
+        static::assertSame('', $error['meta']['documentationLink']);
+    }
+
+    /**
+     * @return \Generator<string, array{string}>
+     */
+    public static function unusableBodyProvider(): \Generator
+    {
+        yield 'gateway returns an html error page instead of json' => ['<html>gateway timeout</html>'];
+        yield 'response has no body at all' => [''];
+        yield 'body is valid json but decodes to a string' => ['"just a string"'];
+        yield 'body is valid json but decodes to a number' => ['42'];
+        yield 'body is valid json but decodes to null' => ['null'];
+        yield 'body is a json list instead of an error object' => ['[1, 2, 3]'];
+    }
+
+    public function testErrorKeepsTheFieldsTheParentParsedWhenTheBodyCannotBeReadTwice(): void
+    {
+        $body = new NoSeekStream(Utils::streamFor((string) json_encode([
+            'code' => 'STORE__EXTENSION_NOT_PURCHASABLE',
+            'title' => 'Extension cannot be purchased',
+            'description' => 'The extension is not available for your shop.',
+            'documentationLink' => 'https://docs.shopware.com/store-error',
+        ], \JSON_THROW_ON_ERROR)));
+
+        $exception = new ExtensionStoreApiException(new ClientException(
+            'Store is not reachable',
+            new Request('GET', '/swplatform/extensionstore/baskets'),
+            new Response(400, [], $body),
+        ));
+
+        $error = $this->firstError($exception);
+
+        static::assertSame('Extension cannot be purchased', $error['title']);
+        static::assertIsArray($error['meta']);
+        static::assertSame('https://docs.shopware.com/store-error', $error['meta']['documentationLink']);
+        static::assertSame('The extension is not available for your shop.', $error['detail']);
+        static::assertSame('', $error['apiCode']);
+        static::assertSame('', $error['description']);
+    }
+
+    /**
+     * The parent declares a sealed error shape, so the extra fields this exception adds are invisible
+     * to static analysis when read straight off the generator.
+     *
+     * @return array<string, mixed>
+     */
+    private function firstError(ExtensionStoreApiException $exception): array
+    {
+        return $exception->getErrors()->current();
+    }
+
+    private function createClientException(string $body): ClientException
+    {
+        return new ClientException(
+            'Store is not reachable',
+            new Request('GET', '/swplatform/extensionstore/baskets'),
+            new Response(400, [], $body),
+        );
+    }
+}