Fix: Content-type request header is missing

Author: erdemkose

src/Client.php

@@ -27,7 +27,6 @@
 use Psr\Http\Message\StreamFactoryInterface;
 use RuntimeException;
 
-use function array_map;
 use function curl_close;
 use function curl_exec;
 use function curl_getinfo;
@@ -43,7 +42,7 @@ class Client implements GeminiClientInterface
     private string $baseUrl = 'https://generativelanguage.googleapis.com';
 
     /**
-     * @var array<string, string>
+     * @var array<string, string|string[]>
      */
     private array $requestHeaders = [];
 
@@ -137,13 +136,11 @@ public function generateContentStream(
             throw new RuntimeException('Gemini API cannot initialize streaming content request');
         }
 
-        $headers = $this->requestHeaders + [
-            'content-type' => 'application/json',
-            self::API_KEY_HEADER_NAME => $this->apiKey,
-        ];
         $headerLines = [];
-        foreach ($headers as $name => $value) {
-            $headerLines[] = "{$name}: {$value}";
+        foreach ($this->getRequestHeaders() as $name => $values) {
+            foreach ((array) $values as $value) {
+                $headerLines[] = "{$name}: {$value}";
+            }
         }
 
         curl_setopt($ch, CURLOPT_URL, "{$this->baseUrl}/v1/{$request->getOperation()}");
@@ -198,17 +195,32 @@ public function withBaseUrl(string $baseUrl): self
     }
 
     /**
-     * @param array<string, string> $headers
+     * @param array<string, string|string[]> $headers
      * @return self
      */
     public function withRequestHeaders(array $headers): self
     {
         $clone = clone $this;
-        $clone->requestHeaders = array_map(strtolower(...), $headers);
+        $clone->requestHeaders = [];
+
+        foreach ($headers as $name => $value) {
+            $clone->requestHeaders[strtolower($name)] = $value;
+        }
 
         return $clone;
     }
 
+    /**
+     * @return array<string, string|string[]>
+     */
+    private function getRequestHeaders(): array
+    {
+        return $this->requestHeaders + [
+            'content-type' => 'application/json',
+            self::API_KEY_HEADER_NAME => $this->apiKey,
+        ];
+    }
+
     /**
      * @throws ClientExceptionInterface
      */
@@ -220,10 +232,9 @@ private function doRequest(RequestInterface $request): string
 
         $uri = "{$this->baseUrl}/v1/{$request->getOperation()}";
         $httpRequest = $this->requestFactory
-            ->createRequest($request->getHttpMethod(), $uri)
-            ->withAddedHeader(self::API_KEY_HEADER_NAME, $this->apiKey);
+            ->createRequest($request->getHttpMethod(), $uri);
 
-        foreach ($this->requestHeaders as $name => $value) {
+        foreach ($this->getRequestHeaders() as $name => $value) {
             $httpRequest = $httpRequest->withAddedHeader($name, $value);
         }
 

tests/Unit/ClientTest.php

@@ -120,7 +120,9 @@ public function testGenerateContent()
             ->with('POST', 'https://generativelanguage.googleapis.com/v1/models/gemini-pro:generateContent')
             ->willReturn($httpRequest);
 
-        $httpRequest = $httpRequest->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key');
+        $httpRequest = $httpRequest
+            ->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key')
+            ->withAddedHeader('content-type', 'application/json');
 
         $stream = Utils::streamFor('{"model":"models\/gemini-pro","contents":[{"parts":[{"text":"this is a text"}],"role":"user"}]}');
         $streamFactory = $this->createMock(StreamFactoryInterface::class);
@@ -173,7 +175,9 @@ public function testEmbedContent()
             ->with('POST', 'https://generativelanguage.googleapis.com/v1/models/embedding-001:embedContent')
             ->willReturn($httpRequest);
 
-        $httpRequest = $httpRequest->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key');
+        $httpRequest = $httpRequest
+            ->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key')
+            ->withAddedHeader('content-type', 'application/json');
 
         $stream = Utils::streamFor('{"content":{"parts":[{"text":"this is a text"}],"role":"user"}}');
         $streamFactory = $this->createMock(StreamFactoryInterface::class);
@@ -221,7 +225,9 @@ public function testCountTokens()
             ->with('POST', 'https://generativelanguage.googleapis.com/v1/models/gemini-pro:countTokens')
             ->willReturn($httpRequest);
 
-        $httpRequest = $httpRequest->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key');
+        $httpRequest = $httpRequest
+            ->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key')
+            ->withAddedHeader('content-type', 'application/json');
 
         $stream = Utils::streamFor('{"model":"models\/gemini-pro","contents":[{"parts":[{"text":"this is a text"}],"role":"user"}]}');
         $streamFactory = $this->createMock(StreamFactoryInterface::class);
@@ -300,7 +306,9 @@ public function testListModels()
             ->with('GET', 'https://generativelanguage.googleapis.com/v1/models')
             ->willReturn($httpRequest);
 
-        $httpRequest = $httpRequest->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key');
+        $httpRequest = $httpRequest
+            ->withAddedHeader(GeminiAPIClientInterface::API_KEY_HEADER_NAME, 'test-api-key')
+            ->withAddedHeader('content-type', 'application/json');
 
         $httpClient = $this->createMock(HttpClientInterface::class);
         $httpClient->expects(self::once())