From 6d0b2267ce0802703af029027ca99ea387a4377b Mon Sep 17 00:00:00 2001
From: Robert Nagy <ronagy@icloud.com>
Date: Mon, 27 Jan 2020 14:46:10 +0100
Subject: [PATCH] stream: fix finished w/ 'close' before 'finish'

Emitting 'close' before 'finish' on a Writable should
result in a premature close error.

PR-URL: https://github.com/nodejs/node/pull/31534
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
---
 lib/internal/streams/end-of-stream.js | 16 ++++++++++++----
 test/parallel/test-stream-finished.js | 13 +++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/internal/streams/end-of-stream.js b/lib/internal/streams/end-of-stream.js
index 877db6fbe1cb34..d6e1c5804eaf4a 100644
--- a/lib/internal/streams/end-of-stream.js
+++ b/lib/internal/streams/end-of-stream.js
@@ -25,6 +25,13 @@ function isWritable(stream) {
     !!stream._writableState;
 }
 
+function isWritableFinished(stream) {
+  if (stream.writableFinished) return true;
+  const wState = stream._writableState;
+  if (!wState || wState.errored) return false;
+  return wState.finished || (wState.ended && wState.length === 0);
+}
+
 function eos(stream, opts, callback) {
   if (arguments.length === 2) {
     callback = opts;
@@ -49,10 +56,11 @@ function eos(stream, opts, callback) {
     if (!stream.writable) onfinish();
   };
 
-  let writableEnded = stream._writableState && stream._writableState.finished;
+  let writableFinished = stream.writableFinished ||
+    (stream._writableState && stream._writableState.finished);
   const onfinish = () => {
     writable = false;
-    writableEnded = true;
+    writableFinished = true;
     if (!readable) callback.call(stream);
   };
 
@@ -75,8 +83,8 @@ function eos(stream, opts, callback) {
         err = new ERR_STREAM_PREMATURE_CLOSE();
       return callback.call(stream, err);
     }
-    if (writable && !writableEnded) {
-      if (!stream._writableState || !stream._writableState.ended)
+    if (writable && !writableFinished) {
+      if (!isWritableFinished(stream))
         err = new ERR_STREAM_PREMATURE_CLOSE();
       return callback.call(stream, err);
     }
diff --git a/test/parallel/test-stream-finished.js b/test/parallel/test-stream-finished.js
index 5b26349d7476e2..f6515a01b8d077 100644
--- a/test/parallel/test-stream-finished.js
+++ b/test/parallel/test-stream-finished.js
@@ -202,3 +202,16 @@ const { promisify } = require('util');
     assert.strictEqual(err.code, 'ERR_STREAM_PREMATURE_CLOSE');
   }));
 }
+
+{
+  const w = new Writable({
+    write(chunk, encoding, callback) {
+      setImmediate(callback);
+    }
+  });
+  finished(w, common.mustCall((err) => {
+    assert.strictEqual(err.code, 'ERR_STREAM_PREMATURE_CLOSE');
+  }));
+  w.end('asd');
+  w.destroy();
+}