From eb9e4e0489dc23ae99abd5429c3c0c9e7d83f033 Mon Sep 17 00:00:00 2001
From: Varun Chandrasekar <varun7.ch@gmail.com>
Date: Thu, 27 Jan 2022 23:54:14 -0800
Subject: [PATCH 1/3] Made the 'Content-type' response header detection
 case-insensitive

---
 src/index.ts | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 46398fd3e..43249c7a8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -535,14 +535,20 @@ export default request
  * todo
  */
 function getResult(response: Dom.Response): Promise<any> {
-  const contentType = response.headers.get('Content-Type')
-  if (contentType && contentType.startsWith('application/json')) {
+  let contentType: string | undefined
+
+  response.headers.forEach((value, key) => {
+    if (key.toLowerCase() === 'Content-Type'.toLowerCase()) {
+      contentType = value
+    }
+  })
+
+  if (contentType && contentType.toLowerCase().startsWith('application/json')) {
     return response.json()
   } else {
     return response.text()
   }
 }
-
 /**
  * helpers
  */

From 0cfa26ae5fb73fae3e848727ac18ccffcc61ea32 Mon Sep 17 00:00:00 2001
From: Varun Chandrasekar <varun7.ch@gmail.com>
Date: Fri, 28 Jan 2022 00:48:14 -0800
Subject: [PATCH 2/3] fix: Made content-type literal in check lower case

---
 src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 43249c7a8..903a2902b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -538,7 +538,7 @@ function getResult(response: Dom.Response): Promise<any> {
   let contentType: string | undefined
 
   response.headers.forEach((value, key) => {
-    if (key.toLowerCase() === 'Content-Type'.toLowerCase()) {
+    if (key.toLowerCase() === 'content-type') {
       contentType = value
     }
   })

From 6675b55a5c576dd74d79d9b4ced34555ec0a6e0e Mon Sep 17 00:00:00 2001
From: Varun Chandrasekar <varun7.ch@gmail.com>
Date: Fri, 28 Jan 2022 14:19:19 -0800
Subject: [PATCH 3/3] Added test

---
 tests/general.test.ts | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/tests/general.test.ts b/tests/general.test.ts
index 8277a5c70..acc701bcd 100644
--- a/tests/general.test.ts
+++ b/tests/general.test.ts
@@ -1,5 +1,6 @@
 import { GraphQLClient, rawRequest, request } from '../src'
 import { setupTestServer } from './__helpers'
+import * as Dom from '../src/types.dom'
 
 const ctx = setupTestServer()
 
@@ -149,3 +150,32 @@ test.skip('extra fetch options', async () => {
     ]
   `)
 })
+
+test('case-insensitive content-type header for custom fetch', async () => {
+  const testData = { data: { test: 'test' } }
+  const testResponseHeaders = new Map()
+  testResponseHeaders.set('ConTENT-type', 'apPliCatiON/JSON')
+
+  const options: Dom.RequestInit = {
+    fetch: function (url: string) {
+      return Promise.resolve({
+        headers: testResponseHeaders,
+        data: testData,
+        json: function () {
+          return testData
+        },
+        text: function () {
+          return JSON.stringify(testData)
+        },
+        ok: true,
+        status: 200,
+        url,
+      })
+    },
+  }
+
+  const client = new GraphQLClient(ctx.url, options)
+  const result = await client.request('{ test }')
+
+  expect(result).toBe(testData.data)
+})