From 42b261bbdc968ad0049010055a70b3455a5e9ebf Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Tue, 10 Feb 2026 23:05:56 +0100
Subject: [PATCH 1/2] doc: fix methods being documented as properties in
 `process.md`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

PR-URL: https://github.com/nodejs/node/pull/61765
Reviewed-By: René <contact.9a5d6388@renegade334.me.uk>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
---
 doc/api/process.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/api/process.md b/doc/api/process.md
index 1c04b53275516f..ec41b349c14443 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -907,7 +907,7 @@ changes:
     description: Change stability index for this feature from Experimental to Stable.
 -->
 
-* Type: {number}
+* Returns: {number}
 
 Gets the amount of free memory that is still available to the process
 (in bytes).
@@ -1081,7 +1081,7 @@ changes:
     description: Aligned return value with `uv_get_constrained_memory`.
 -->
 
-* Type: {number}
+* Returns: {number}
 
 Gets the amount of memory available to the process (in bytes) based on
 limits imposed by the OS. If there is no such constraint, or the constraint

From 04946a7a8cd6a0b8c1ffc78e860490dfd2defeef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9?= <contact.9a5d6388@renegade334.me.uk>
Date: Wed, 11 Feb 2026 02:15:43 +0000
Subject: [PATCH 2/2] stream: rename `Duplex.toWeb()` type option to
 `readableType`

PR-URL: https://github.com/nodejs/node/pull/61632
Refs: https://github.com/nodejs/node/pull/58664
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Mattias Buelens <mattias@buelens.com>
---
 doc/api/deprecations.md             | 16 ++++++++++++++++
 doc/api/stream.md                   | 13 ++++++++++---
 lib/internal/webstreams/adapters.js | 14 ++++++++++----
 test/parallel/test-stream-duplex.js |  6 +++++-
 4 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/doc/api/deprecations.md b/doc/api/deprecations.md
index 78268b2b666138..bb8ca3e63e0096 100644
--- a/doc/api/deprecations.md
+++ b/doc/api/deprecations.md
@@ -4415,6 +4415,21 @@ import { opendir } from 'node:fs/promises';
 }
 ```
 
+### DEP0201: Passing `options.type` to `Duplex.toWeb()`
+
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/61632
+    description: Documentation-only deprecation.
+-->
+
+Type: Documentation-only
+
+Passing the `type` option to [`Duplex.toWeb()`][] is deprecated. To specify the
+type of the readable half of the constructed readable-writable pair, use the
+`readableType` option instead.
+
 [DEP0142]: #dep0142-repl_builtinlibs
 [NIST SP 800-38D]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf
 [RFC 6066]: https://tools.ietf.org/html/rfc6066#section-3
@@ -4433,6 +4448,7 @@ import { opendir } from 'node:fs/promises';
 [`Buffer.isBuffer()`]: buffer.md#static-method-bufferisbufferobj
 [`Cipheriv`]: crypto.md#class-cipheriv
 [`Decipheriv`]: crypto.md#class-decipheriv
+[`Duplex.toWeb()`]: stream.md#streamduplextowebstreamduplex-options
 [`Error.isError`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/isError
 [`REPLServer.clearBufferedCommand()`]: repl.md#replserverclearbufferedcommand
 [`ReadStream.open()`]: fs.md#class-fsreadstream
diff --git a/doc/api/stream.md b/doc/api/stream.md
index ef6dd51eabfd5e..73009939fe721b 100644
--- a/doc/api/stream.md
+++ b/doc/api/stream.md
@@ -3219,7 +3219,8 @@ changes:
       If no value is provided, the size will be `1` for all the chunks.
       * `chunk` {any}
       * Returns: {number}
-  * `type` {string} Must be 'bytes' or undefined.
+  * `type` {string} Specifies the type of the created `ReadableStream`. Must be
+    `'bytes'` or undefined.
 * Returns: {ReadableStream}
 
 ### `stream.Writable.fromWeb(writableStream[, options])`
@@ -3398,9 +3399,13 @@ duplex.once('readable', () => console.log('readable', duplex.read()));
 <!-- YAML
 added: v17.0.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/61632
+    description: Added the 'readableType' option to specify the ReadableStream
+                 type. The 'type' option is deprecated.
   - version: v25.4.0
     pr-url: https://github.com/nodejs/node/pull/58664
-    description: Add 'type' option to specify 'bytes'.
+    description: Added the 'type' option to specify the ReadableStream type.
   - version:
       - v24.0.0
       - v22.17.0
@@ -3410,7 +3415,9 @@ changes:
 
 * `streamDuplex` {stream.Duplex}
 * `options` {Object}
-  * `type` {string} Must be 'bytes' or undefined.
+  * `readableType` {string} Specifies the type of the `ReadableStream` half of
+    the created readable-writable pair. Must be `'bytes'` or undefined.
+    (`options.type` is a deprecated alias for this option.)
 * Returns: {Object}
   * `readable` {ReadableStream}
   * `writable` {WritableStream}
diff --git a/lib/internal/webstreams/adapters.js b/lib/internal/webstreams/adapters.js
index 8d5c1d9fc6d9d0..ed9847f250f1ca 100644
--- a/lib/internal/webstreams/adapters.js
+++ b/lib/internal/webstreams/adapters.js
@@ -624,7 +624,7 @@ function newStreamReadableFromReadableStream(readableStream, options = kEmptyObj
 
 /**
  * @param {Duplex} duplex
- * @param {{ type?: 'bytes' }} [options]
+ * @param {{ readableType?: 'bytes' }} [options]
  * @returns {ReadableWritablePair}
  */
 function newReadableWritablePairFromDuplex(duplex, options = kEmptyObject) {
@@ -641,9 +641,15 @@ function newReadableWritablePairFromDuplex(duplex, options = kEmptyObject) {
 
   validateObject(options, 'options');
 
+  const readableOptions = {
+    __proto__: null,
+    // DEP0201: 'options.type' is a deprecated alias for 'options.readableType'
+    type: options.readableType ?? options.type,
+  };
+
   if (isDestroyed(duplex)) {
     const writable = new WritableStream();
-    const readable = new ReadableStream({ type: options.type });
+    const readable = new ReadableStream({ type: readableOptions.type });
     writable.close();
     readable.cancel();
     return { readable, writable };
@@ -659,8 +665,8 @@ function newReadableWritablePairFromDuplex(duplex, options = kEmptyObject) {
 
   const readable =
     isReadable(duplex) ?
-      newReadableStreamFromStreamReadable(duplex, options) :
-      new ReadableStream({ type: options.type });
+      newReadableStreamFromStreamReadable(duplex, readableOptions) :
+      new ReadableStream({ type: readableOptions.type });
 
   if (!isReadable(duplex))
     readable.cancel();
diff --git a/test/parallel/test-stream-duplex.js b/test/parallel/test-stream-duplex.js
index 6fa5541c555c28..862e1fec0baf6c 100644
--- a/test/parallel/test-stream-duplex.js
+++ b/test/parallel/test-stream-duplex.js
@@ -147,10 +147,14 @@ process.on('exit', () => {
     })
   });
 
-  const { writable, readable } = Duplex.toWeb(duplex, { type: 'bytes' });
+  const { writable, readable } = Duplex.toWeb(duplex, { readableType: 'bytes' });
   writable.getWriter().write(dataToWrite);
   const data = new Uint8Array(dataToRead.length);
   readable.getReader({ mode: 'byob' }).read(data).then(common.mustCall((result) => {
     assert.deepStrictEqual(Buffer.from(result.value), dataToRead);
   }));
+
+  // Ensure that the originally-named `options.type` still works as an alias for `options.readableType`
+  // `getReader({ mode: 'byob' })` throws if the underlying ReadableStream is not a byte stream
+  Duplex.toWeb(duplex, { type: 'bytes' }).readable.getReader({ mode: 'byob' });
 }