http2: use getter replace use directly _witableState.finished

doc/api/stream.md

@@ -502,6 +502,16 @@ This property contains the number of bytes (or objects) in the queue
 ready to be written. The value provides introspection data regarding
 the status of the `highWaterMark`.
 
+##### writable.writableFinished
+<!-- YAML
+added: v12.4.0
+-->
+
+* {boolean}
+
+Is `true` if all data has been flushed to the underlying system. After
+the [`'finish'`][] event has been emitted.
+
 ##### writable.writableObjectMode
 <!-- YAML
 added: v12.3.0

lib/_stream_duplex.js

@@ -98,6 +98,16 @@ Object.defineProperty(Duplex.prototype, 'writableLength', {
   }
 });
 
+Object.defineProperty(Duplex.prototype, 'writableFinished', {
+  // Making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get() {
+    return this._writableState.finished;
+  }
+});
+
 // The no-half-open enforcer
 function onend() {
   // If the writable side ended, then we're ok.

lib/_stream_writable.js

@@ -714,6 +714,16 @@ Object.defineProperty(Writable.prototype, 'writableObjectMode', {
   }
 });
 
+Object.defineProperty(Writable.prototype, 'writableFinished', {
+  // Making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get() {
+    return this._writableState.finished;
+  }
+});
+
 Writable.prototype.destroy = destroyImpl.destroy;
 Writable.prototype._undestroy = destroyImpl.undestroy;
 Writable.prototype._destroy = function(err, cb) {

lib/internal/http2/core.js

@@ -1556,7 +1556,7 @@ function closeStream(stream, code, rstStreamStatus = kSubmitRstStream) {
   stream.setTimeout(0);
   stream.removeAllListeners('timeout');
 
-  const { ending, finished } = stream._writableState;
+  const { ending } = stream._writableState;
 
   if (!ending) {
     // If the writable side of the Http2Stream is still open, emit the
@@ -1572,7 +1572,7 @@ function closeStream(stream, code, rstStreamStatus = kSubmitRstStream) {
 
   if (rstStreamStatus !== kNoRstStream) {
     const finishFn = finishCloseStream.bind(stream, code);
-    if (!ending || finished || code !== NGHTTP2_NO_ERROR ||
+    if (!ending || stream.writableFinished || code !== NGHTTP2_NO_ERROR ||
         rstStreamStatus === kForceRstStream)
       finishFn();
     else
@@ -1982,8 +1982,7 @@ class Http2Stream extends Duplex {
       return;
     }
 
-    // TODO(mcollina): remove usage of _*State properties
-    if (this._writableState.finished) {
+    if (this.writableFinished) {
       if (!this.readable && this.closed) {
         this.destroy();
         return;

test/parallel/test-stream-duplex-writable-finished.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const common = require('../common');
+const { Duplex } = require('stream');
+const assert = require('assert');
+
+// basic
+{
+  // Find it on Duplex.prototype
+  assert(Duplex.prototype.hasOwnProperty('writableFinished'));
+}
+
+// event
+{
+  const duplex = new Duplex();
+
+  duplex._write = (chunk, encoding, cb) => {
+    // The state finished should start in false.
+    assert.strictEqual(duplex.writableFinished, false);
+    cb();
+  };
+
+  duplex.on('finish', common.mustCall(() => {
+    assert.strictEqual(duplex.writableFinished, true);
+  }));
+
+  duplex.end('testing finished state', common.mustCall(() => {
+    assert.strictEqual(duplex.writableFinished, true);
+  }));
+}

test/parallel/test-stream-writable-finished.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const common = require('../common');
+const { Writable } = require('stream');
+const assert = require('assert');
+
+// basic
+{
+  // Find it on Writable.prototype
+  assert(Writable.prototype.hasOwnProperty('writableFinished'));
+}
+
+// event
+{
+  const writable = new Writable();
+
+  writable._write = (chunk, encoding, cb) => {
+    // The state finished should start in false.
+    assert.strictEqual(writable.writableFinished, false);
+    cb();
+  };
+
+  writable.on('finish', common.mustCall(() => {
+    assert.strictEqual(writable.writableFinished, true);
+  }));
+
+  writable.end('testing finished state', common.mustCall(() => {
+    assert.strictEqual(writable.writableFinished, true);
+  }));
+}