From 89f99f9c84950da532f620daac26bb246d8f3a0b Mon Sep 17 00:00:00 2001
From: Lenz Weber-Tronic <lorenz.weber-tronic@apollographql.com>
Date: Tue, 12 Sep 2023 14:37:50 +0200
Subject: [PATCH] read json and body text concurrently

---
 src/link/http/__tests__/HttpLink.ts        |  6 ++----
 src/link/http/parseAndCheckHttpResponse.ts | 18 ++++++++++++------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/link/http/__tests__/HttpLink.ts b/src/link/http/__tests__/HttpLink.ts
index 6c9c9f191c4..5346221dc5a 100644
--- a/src/link/http/__tests__/HttpLink.ts
+++ b/src/link/http/__tests__/HttpLink.ts
@@ -1320,8 +1320,7 @@ describe("HttpLink", () => {
           makeCallback(resolve, reject, (e: ServerError) => {
             expect(e.message).toMatch(/Received status code 302/);
             expect(e.statusCode).toBe(302);
-            // JSON.parse consumed the buffer, we cannot read it with `.text` anymore
-            expect(e.result).toEqual(undefined);
+            expect(e.result).toEqual("Error! Foo bar");
           })
         );
       }
@@ -1590,8 +1589,7 @@ describe("HttpLink", () => {
             expect(e.message).toMatch(/JSON/);
             expect(e.statusCode).toBe(200);
             expect(e.response).toBeDefined();
-            // bodyText cannot be read a second time - the buffer has been consumed by `Response.json()`
-            expect(e.bodyText).toBe("");
+            expect(e.bodyText).toBe("{");
           })
         );
       }
diff --git a/src/link/http/parseAndCheckHttpResponse.ts b/src/link/http/parseAndCheckHttpResponse.ts
index b40323cb0cc..03df2a50454 100644
--- a/src/link/http/parseAndCheckHttpResponse.ts
+++ b/src/link/http/parseAndCheckHttpResponse.ts
@@ -133,8 +133,17 @@ export async function parseJsonBody<T>(
   response: Response,
   bodyText?: string
 ): Promise<T> {
-  const tryParseAsync = () =>
-    bodyText !== undefined ? JSON.parse(bodyText) : response.json();
+  const tryParseAsync = () => {
+    if (bodyText !== undefined) return JSON.parse(bodyText);
+
+    const json = response.clone().json();
+    return response
+      .text()
+      .then((text) => {
+        bodyText = text;
+      })
+      .then(() => json);
+  };
   if (response.status >= 300) {
     // Network error
     throwServerError(
@@ -151,10 +160,7 @@ export async function parseJsonBody<T>(
     parseError.name = "ServerParseError";
     parseError.response = response;
     parseError.statusCode = response.status;
-    parseError.bodyText =
-      bodyText ||
-      // at this point, the response has already been consumed, so we cannot get the body anymore
-      "";
+    parseError.bodyText = bodyText!;
     throw parseError;
   }
 }