fix: add

Author: ghernandez345

README.md

@@ -43,6 +43,7 @@ This project "fixes" the following global APIs, overriding whichever polyfills t
 - `URL`
 - `URLSearchParams`
 - `BroadcastChannel`
+- `TransformStream`
 
 ## Getting started
 

index.js

@@ -21,6 +21,7 @@ class FixedJSDOMEnvironment extends JSDOMEnvironment {
     this.global.URLSearchParams = URLSearchParams
 
     this.global.BroadcastChannel = BroadcastChannel
+    this.global.TransformStream = TransformStream
   }
 }
 

index.test.js

@@ -163,3 +163,9 @@ test('exposes "BroadcastChannel"', () => {
   expect(channel).toBeInstanceOf(BuiltinBroadcastChannel)
   channel.unref()
 })
+
+test('exposes "TransformStream"', () => {
+  expect(globalThis).toHaveProperty('TransformStream')
+  const channel = new TransformStream()
+  expect(channel).toBeInstanceOf(TransformStream)
+})