From 49f9bbbf3d40758e3c6fa0b7f63839d12e3ff3d0 Mon Sep 17 00:00:00 2001
From: Offir Golan <offirgolan@gmail.com>
Date: Tue, 1 Jun 2021 18:02:43 -0700
Subject: [PATCH] fix: Clone the arraybuffer if it fails instanceof check

---
 packages/@pollyjs/adapter-fetch/src/index.js  | 21 +++++++++++++++++--
 packages/@pollyjs/adapter-xhr/src/index.js    | 21 +++++++++++++++++--
 packages/@pollyjs/utils/src/index.js          |  1 +
 .../utils/src/utils/clone-arraybuffer.js      | 12 +++++++++++
 4 files changed, 51 insertions(+), 4 deletions(-)
 create mode 100644 packages/@pollyjs/utils/src/utils/clone-arraybuffer.js

diff --git a/packages/@pollyjs/adapter-fetch/src/index.js b/packages/@pollyjs/adapter-fetch/src/index.js
index 75c8c9c7..d755bc01 100644
--- a/packages/@pollyjs/adapter-fetch/src/index.js
+++ b/packages/@pollyjs/adapter-fetch/src/index.js
@@ -1,5 +1,5 @@
 import Adapter from '@pollyjs/adapter';
-import { isBufferUtf8Representable } from '@pollyjs/utils';
+import { cloneArrayBuffer, isBufferUtf8Representable } from '@pollyjs/utils';
 import isNode from 'detect-node';
 import { Buffer } from 'buffer/';
 import bufferToArrayBuffer from 'to-arraybuffer';
@@ -167,7 +167,24 @@ export default class FetchAdapter extends Adapter {
       }
     ]);
 
-    const buffer = Buffer.from(await response.arrayBuffer());
+    let arrayBuffer = await response.arrayBuffer();
+
+    /*
+      If the returned array buffer is not an instance of the global ArrayBuffer,
+      clone it in order to pass Buffer.from's instanceof check. This can happen
+      when using this adapter with a different context.
+
+      https://github.com/feross/buffer/issues/289
+    */
+    if (
+      arrayBuffer &&
+      !(arrayBuffer instanceof ArrayBuffer) &&
+      'byteLength' in arrayBuffer
+    ) {
+      arrayBuffer = cloneArrayBuffer(arrayBuffer);
+    }
+
+    const buffer = Buffer.from(arrayBuffer);
     const isBinaryBuffer = !isBufferUtf8Representable(buffer);
 
     return {
diff --git a/packages/@pollyjs/adapter-xhr/src/index.js b/packages/@pollyjs/adapter-xhr/src/index.js
index ca51964e..de33bf5b 100644
--- a/packages/@pollyjs/adapter-xhr/src/index.js
+++ b/packages/@pollyjs/adapter-xhr/src/index.js
@@ -1,6 +1,6 @@
 import fakeXhr from '@offirgolan/nise/lib/fake-xhr';
 import Adapter from '@pollyjs/adapter';
-import { isBufferUtf8Representable } from '@pollyjs/utils';
+import { cloneArrayBuffer, isBufferUtf8Representable } from '@pollyjs/utils';
 import { Buffer } from 'buffer/';
 import bufferToArrayBuffer from 'to-arraybuffer';
 
@@ -112,7 +112,24 @@ export default class XHRAdapter extends Adapter {
 
     // responseType will either be `arraybuffer` or `text`
     if (xhr.responseType === 'arraybuffer') {
-      const buffer = Buffer.from(xhr.response);
+      let arrayBuffer = xhr.response;
+
+      /*
+        If the returned array buffer is not an instance of the global ArrayBuffer,
+        clone it in order to pass Buffer.from's instanceof check. This can happen
+        when using this adapter with a different context.
+
+        https://github.com/feross/buffer/issues/289
+      */
+      if (
+        arrayBuffer &&
+        !(arrayBuffer instanceof ArrayBuffer) &&
+        'byteLength' in arrayBuffer
+      ) {
+        arrayBuffer = cloneArrayBuffer(arrayBuffer);
+      }
+
+      const buffer = Buffer.from(arrayBuffer);
 
       isBinary = !isBufferUtf8Representable(buffer);
       body = buffer.toString(isBinary ? 'hex' : 'utf8');
diff --git a/packages/@pollyjs/utils/src/index.js b/packages/@pollyjs/utils/src/index.js
index 8e803735..086cc67b 100644
--- a/packages/@pollyjs/utils/src/index.js
+++ b/packages/@pollyjs/utils/src/index.js
@@ -17,3 +17,4 @@ export { default as URL } from './utils/url';
 export {
   default as isBufferUtf8Representable
 } from './utils/is-buffer-utf8-representable';
+export { default as cloneArrayBuffer } from './utils/clone-arraybuffer';
diff --git a/packages/@pollyjs/utils/src/utils/clone-arraybuffer.js b/packages/@pollyjs/utils/src/utils/clone-arraybuffer.js
new file mode 100644
index 00000000..66908056
--- /dev/null
+++ b/packages/@pollyjs/utils/src/utils/clone-arraybuffer.js
@@ -0,0 +1,12 @@
+/**
+ * Clone an array buffer
+ *
+ * @param {ArrayBuffer} arrayBuffer
+ */
+export default function cloneArrayBuffer(arrayBuffer) {
+  const clonedArrayBuffer = new ArrayBuffer(arrayBuffer.byteLength);
+
+  new Uint8Array(clonedArrayBuffer).set(new Uint8Array(arrayBuffer));
+
+  return clonedArrayBuffer;
+}