From 144a216b7340117c1bed99ae91b3ee8b4f99710a Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Thu, 18 Nov 2021 16:44:14 +0100
Subject: [PATCH] stream: fix finished regression when working with legacy
 Stream

Signed-off-by: Matteo Collina <hello@matteocollina.com>
---
 lib/internal/streams/end-of-stream.js |  4 ++--
 test/parallel/test-stream-finished.js | 11 ++++++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/lib/internal/streams/end-of-stream.js b/lib/internal/streams/end-of-stream.js
index c224b44eac6631..ab60f5a7ea78f1 100644
--- a/lib/internal/streams/end-of-stream.js
+++ b/lib/internal/streams/end-of-stream.js
@@ -165,13 +165,13 @@ function eos(stream, options, callback) {
   } else if (
     !readable &&
     (!willEmitClose || isReadable(stream)) &&
-    (writableFinished || !isWritable(stream))
+    (writableFinished || isWritable(stream) === false)
   ) {
     process.nextTick(onclose);
   } else if (
     !writable &&
     (!willEmitClose || isWritable(stream)) &&
-    (readableFinished || !isReadable(stream))
+    (readableFinished || isReadable(stream) === false)
   ) {
     process.nextTick(onclose);
   } else if ((rState && stream.req && stream.aborted)) {
diff --git a/test/parallel/test-stream-finished.js b/test/parallel/test-stream-finished.js
index 8ada0c4c348cb7..f1b90772aa8100 100644
--- a/test/parallel/test-stream-finished.js
+++ b/test/parallel/test-stream-finished.js
@@ -7,7 +7,8 @@ const {
   Transform,
   finished,
   Duplex,
-  PassThrough
+  PassThrough,
+  Stream
 } = require('stream');
 const assert = require('assert');
 const EE = require('events');
@@ -630,3 +631,11 @@ testClosed((opts) => new Writable({ write() {}, ...opts }));
     }));
   }));
 }
+
+{
+  // Legacy Streams do not inherit from Readable or Writable.
+  // We cannot really assume anything about them, so we cannot close them
+  // automatically.
+  const s = new Stream();
+  finished(s, common.mustNotCall());
+}