fix(client): drop content-type on any bodyless request, not just delete

src/Core/BaseClient.php

@@ -146,6 +146,13 @@ protected function buildRequest(
             ...$idempotencyHeaders,
         ];
 
+        // Generated methods always pass `body` for operations that define a request
+        // body, so only elide the content-type header when the operation has no body
+        // at all, not when an optional body param was omitted.
+        if (null === $body && !array_key_exists('Content-Type', $headers)) {
+            unset($mergedHeaders['Content-Type']);
+        }
+
         $req = ['method' => strtoupper($method), 'path' => $uri, 'query' => $mergedQuery, 'headers' => $mergedHeaders, 'body' => $body];
 
         return [$req, $options];

src/Services/WebhooksRawService.php

@@ -263,7 +263,6 @@ public function delete(
             $params,
             $requestOptions,
         );
-
         // @phpstan-ignore-next-line return.type
         return $this->client->request(
             method: 'delete',

tests/ClientTest.php

@@ -41,4 +41,93 @@ public function testDefaultHeaders(): void
             $this->assertNotEmpty($sent);
         }
     }
+
+    public function testBodylessDeleteOmitsContentType(): void
+    {
+        $transporter = new Client;
+        $transporter->setDefaultResponse(
+            Psr17FactoryDiscovery::findResponseFactory()->createResponse()->withStatus(204)
+        );
+
+        $client = new \SentDm\Client(
+            baseUrl: 'http://localhost',
+            apiKey: 'My API Key',
+            requestOptions: ['transporter' => $transporter],
+        );
+
+        $client->webhooks->delete('d4f5a6b7-c8d9-4e0f-a1b2-c3d4e5f6a7b8');
+
+        $this->assertNotFalse($requested = $transporter->getRequests()[0] ?? false);
+        $this->assertSame('DELETE', $requested->getMethod());
+        $this->assertSame('', $requested->getHeaderLine('content-type'));
+        $this->assertSame('', (string) $requested->getBody());
+    }
+
+    public function testBodylessGetOmitsContentType(): void
+    {
+        $transporter = new Client;
+        $mockRsp = Psr17FactoryDiscovery::findResponseFactory()
+            ->createResponse()
+            ->withStatus(200)
+            ->withHeader('Content-Type', 'application/json')
+            ->withBody(Psr17FactoryDiscovery::findStreamFactory()->createStream(json_encode([], flags: Util::JSON_ENCODE_FLAGS) ?: ''))
+        ;
+        $transporter->setDefaultResponse($mockRsp);
+
+        $client = new \SentDm\Client(
+            baseUrl: 'http://localhost',
+            apiKey: 'My API Key',
+            requestOptions: ['transporter' => $transporter],
+        );
+
+        $client->messages->retrieveStatus('msg_123');
+
+        $this->assertNotFalse($requested = $transporter->getRequests()[0] ?? false);
+        $this->assertSame('GET', $requested->getMethod());
+        $this->assertSame('', $requested->getHeaderLine('content-type'));
+    }
+
+    public function testDeleteWithExplicitBodyKeepsContentType(): void
+    {
+        $transporter = new Client;
+        $transporter->setDefaultResponse(
+            Psr17FactoryDiscovery::findResponseFactory()->createResponse()->withStatus(204)
+        );
+
+        $client = new \SentDm\Client(
+            baseUrl: 'http://localhost',
+            apiKey: 'My API Key',
+            requestOptions: ['transporter' => $transporter],
+        );
+
+        $client->profiles->delete('770e8400-e29b-41d4-a716-446655440002');
+
+        $this->assertNotFalse($requested = $transporter->getRequests()[0] ?? false);
+        $this->assertSame('DELETE', $requested->getMethod());
+        $this->assertSame('application/json', $requested->getHeaderLine('content-type'));
+        $this->assertSame('{}', (string) $requested->getBody());
+    }
+
+    public function testBodylessRequestKeepsAnExplicitContentTypeOverride(): void
+    {
+        $transporter = new Client;
+        $transporter->setDefaultResponse(
+            Psr17FactoryDiscovery::findResponseFactory()->createResponse()->withStatus(204)
+        );
+
+        $client = new \SentDm\Client(
+            baseUrl: 'http://localhost',
+            apiKey: 'My API Key',
+            requestOptions: ['transporter' => $transporter],
+        );
+
+        $client->request(
+            method: 'delete',
+            path: 'v3/webhooks/d4f5a6b7-c8d9-4e0f-a1b2-c3d4e5f6a7b8',
+            headers: ['Content-Type' => 'application/json'],
+        );
+
+        $this->assertNotFalse($requested = $transporter->getRequests()[0] ?? false);
+        $this->assertSame('application/json', $requested->getHeaderLine('content-type'));
+    }
 }