fix(body mixin): only allow Uint8Array chunks (nodejs#1550)

lib/fetch/body.js

@@ -291,6 +291,10 @@ function bodyMixinMethods (instance) {
       const chunks = []
 
       for await (const chunk of consumeBody(this[kState].body)) {
+        if (!isUint8Array(chunk)) {
+          throw new TypeError('Expected Uint8Array chunk')
+        }
+
         // Assemble one final large blob with Uint8Array's can exhaust memory.
         // That's why we create create multiple blob's and using references
         chunks.push(new Blob([chunk]))
@@ -314,6 +318,10 @@ function bodyMixinMethods (instance) {
         let offset = 0
 
         for await (const chunk of consumeBody(this[kState].body)) {
+          if (!isUint8Array(chunk)) {
+            throw new TypeError('Expected Uint8Array chunk')
+          }
+
           buffer.set(chunk, offset)
           offset += chunk.length
         }
@@ -331,6 +339,10 @@ function bodyMixinMethods (instance) {
       let size = 0
 
       for await (const chunk of consumeBody(this[kState].body)) {
+        if (!isUint8Array(chunk)) {
+          throw new TypeError('Expected Uint8Array chunk')
+        }
+
         chunks.push(chunk)
         size += chunk.byteLength
       }
@@ -355,6 +367,10 @@ function bodyMixinMethods (instance) {
       const textDecoder = new TextDecoder()
 
       for await (const chunk of consumeBody(this[kState].body)) {
+        if (!isUint8Array(chunk)) {
+          throw new TypeError('Expected Uint8Array chunk')
+        }
+
         result += textDecoder.decode(chunk, { stream: true })
       }
 

test/fetch/response.js

@@ -4,6 +4,7 @@ const { test } = require('tap')
 const {
   Response
 } = require('../../')
+const { ReadableStream } = require('stream/web')
 
 test('arg validation', async (t) => {
   // constructor
@@ -164,3 +165,68 @@ test('Modifying headers using Headers.prototype.set', (t) => {
 
   t.end()
 })
+
+// https://github.com/nodejs/node/issues/43838
+test('constructing a Response with a ReadableStream body', async (t) => {
+  const text = '{"foo":"bar"}'
+  const uint8 = new TextEncoder().encode(text)
+
+  t.test('Readable stream with Uint8Array chunks', async (t) => {
+    const readable = new ReadableStream({
+      start (controller) {
+        controller.enqueue(uint8)
+        controller.close()
+      }
+    })
+
+    const response1 = new Response(readable)
+    const response2 = response1.clone()
+    const response3 = response1.clone()
+
+    t.equal(await response1.text(), text)
+    t.same(await response2.arrayBuffer(), uint8.buffer)
+    t.same(await response3.json(), JSON.parse(text))
+
+    t.end()
+  })
+
+  t.test('Readable stream with non-Uint8Array chunks', async (t) => {
+    const readable = new ReadableStream({
+      start (controller) {
+        controller.enqueue(text) // string
+        controller.close()
+      }
+    })
+
+    const response = new Response(readable)
+
+    await t.rejects(response.text(), TypeError)
+
+    t.end()
+  })
+
+  t.test('Readable with ArrayBuffer chunk still throws', async (t) => {
+    const readable = new ReadableStream({
+      start (controller) {
+        controller.enqueue(uint8.buffer)
+        controller.close()
+      }
+    })
+
+    const response1 = new Response(readable)
+    const response2 = response1.clone()
+    const response3 = response1.clone()
+    // const response4 = response1.clone()
+
+    await t.rejects(response1.arrayBuffer(), TypeError)
+    await t.rejects(response2.text(), TypeError)
+    await t.rejects(response3.json(), TypeError)
+    // TODO: on Node v16.8.0, this throws a TypeError
+    // because the body is detected as disturbed.
+    // await t.rejects(response4.blob(), TypeError)
+
+    t.end()
+  })
+
+  t.end()
+})