stream: add Symbol.toStringTag to Compression Streams

PR-URL: #50712
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: panva

lib/internal/webstreams/compression.js

@@ -2,6 +2,7 @@
 
 const {
   ObjectDefineProperties,
+  SymbolToStringTag,
 } = primordials;
 
 const {
@@ -137,11 +138,21 @@ class DecompressionStream {
 ObjectDefineProperties(CompressionStream.prototype, {
   readable: kEnumerableProperty,
   writable: kEnumerableProperty,
+  [SymbolToStringTag]: {
+    __proto__: null,
+    configurable: true,
+    value: 'CompressionStream',
+  },
 });
 
 ObjectDefineProperties(DecompressionStream.prototype, {
   readable: kEnumerableProperty,
   writable: kEnumerableProperty,
+  [SymbolToStringTag]: {
+    __proto__: null,
+    configurable: true,
+    value: 'DecompressionStream',
+  },
 });
 
 module.exports = {

test/parallel/test-whatwg-webstreams-compression.js

@@ -15,6 +15,9 @@ async function test(format) {
   const gzip = new CompressionStream(format);
   const gunzip = new DecompressionStream(format);
 
+  assert.strictEqual(gzip[Symbol.toStringTag], 'CompressionStream');
+  assert.strictEqual(gunzip[Symbol.toStringTag], 'DecompressionStream');
+
   gzip.readable.pipeTo(gunzip.writable).then(common.mustCall());
 
   const reader = gunzip.readable.getReader();