stream: fix the ReadableStreamBYOBReader error message

PR-URL: #40846
Reviewed-By: Robert Nagy <ronagy@icloud.com>

Author: jasnell

lib/internal/webstreams/readablestream.js

@@ -508,6 +508,8 @@ class ReadableStream {
     return customInspect(depth, options, this[kType], {
       locked: this.locked,
       state: this[kState].state,
+      supportsBYOB:
+        this[kState].controller instanceof ReadableByteStreamController,
     });
   }
 
@@ -1745,7 +1747,7 @@ function setupReadableStreamBYOBReader(reader, stream) {
     controller,
   } = stream[kState];
   if (!isReadableByteStreamController(controller))
-    throw new ERR_INVALID_ARG_VALUE('reader', reader, 'must be a byte stream');
+    throw new ERR_INVALID_ARG_VALUE('stream', stream, 'must be a byte stream');
   readableStreamReaderGenericInitialize(reader, stream);
   reader[kState].readIntoRequests = [];
 }

test/parallel/test-whatwg-readablestream.js

@@ -1410,10 +1410,12 @@ class Source {
 
   assert.strictEqual(
     inspect(readable),
-    'ReadableStream { locked: false, state: \'readable\' }');
+    'ReadableStream { locked: false, state: \'readable\', ' +
+    'supportsBYOB: false }');
   assert.strictEqual(
     inspect(readable, { depth: null }),
-    'ReadableStream { locked: false, state: \'readable\' }');
+    'ReadableStream { locked: false, state: \'readable\', ' +
+    'supportsBYOB: false }');
   assert.strictEqual(
     inspect(readable, { depth: 0 }),
     'ReadableStream [Object]');