Clean up adding headers and multiple Response objects

Author: jer-k

src/startServerAndCreateNextHandler.ts

@@ -36,6 +36,11 @@ function startServerAndCreateNextHandler<
       },
     });
 
+    const headers: Record<string, string> = {};
+    for (const [key, value] of httpGraphQLResponse.headers) {
+      headers[key] = value;
+    }
+
     if (isNextApiRequest(req)) {
       if (!res) {
         throw new Error('API Routes require you to pass both the req and res object.');
@@ -50,9 +55,7 @@ function startServerAndCreateNextHandler<
       if (httpGraphQLResponse.body.kind === 'complete') {
         res.send(httpGraphQLResponse.body.string);
       } else {
-        res.writeHead(200, {
-          'Content-Type': 'multipart/mixed; boundary="-"',
-        });
+        res.writeHead(200, headers);
 
         for await (const chunk of httpGraphQLResponse.body.asyncIterator) {
           res.write(chunk);
@@ -63,36 +66,25 @@ function startServerAndCreateNextHandler<
       return;
     }
 
-    const headers: Record<string, string> = {};
-    for (const [key, value] of httpGraphQLResponse.headers) {
-      headers[key] = value;
-    }
+    let responseObject: string | ReadableStream;
 
     if (httpGraphQLResponse.body.kind === 'complete') {
-      // eslint-disable-next-line consistent-return
-      return new Response(httpGraphQLResponse.body.string, {
-        headers,
-        status: httpGraphQLResponse.status || 200,
+      responseObject = httpGraphQLResponse.body.string;
+    } else {
+      const responseBody = httpGraphQLResponse.body;
+      responseObject = new ReadableStream({
+        async start(controller) {
+          for await (const chunk of responseBody.asyncIterator) {
+            controller.enqueue(chunk);
+          }
+          controller.close();
+        },
       });
     }
 
-    const responseBody = httpGraphQLResponse.body;
-    const stream = new ReadableStream({
-      async start(controller) {
-        for await (const chunk of responseBody.asyncIterator) {
-          controller.enqueue(chunk);
-        }
-        controller.close();
-      },
-    });
-
     // eslint-disable-next-line consistent-return
-    return new Response(stream, {
-      headers: {
-        ...headers,
-        'Content-Type': 'application/json',
-        'Transfer-Encoding': 'chunked',
-      },
+    return new Response(responseObject, {
+      headers,
       status: httpGraphQLResponse.status || 200,
     });
   }