streams: implement streams to webstreams adapters

Experimental adapters for the webstreams API

Signed-off-by: James M Snell <jasnell@gmail.com>

doc/api/webstreams.md

@@ -1118,5 +1118,90 @@ added: REPLACEME
   * `chunk` {any}
   * Returns: {number}
 
+## Node.js Streams Adapters
+
+The Node.js Streams Adapters are additional Node.js-specific APIs that are used
+to adapt `ReadableStream`, `WritableStream`, and `TransformStream` objects to
+the Node.js streams API.
+
+### Adapting Node.js streams to Web Streams
+
+#### `newReadableStreamFromStreamReadable(streamReadable)`
+
+* `streamReadable` {stream.Readable}
+* Returns: {ReadableStream}
+
+Creates and returns a {ReadableStream} that wraps a {stream.Readable}.
+
+#### `newReadableWritablePairFromStreamDuplex(streamDuplex)`
+
+* `streamDuplex` {stream.Duplex}
+* Returns: {Object}
+  * `readable` {ReadableStream}
+  * `writable` {WritableStream}
+
+Creates and returns a {ReadableStream} and {WritableStream} pair that wraps a
+{stream.Duplex}.
+
+#### `newWritableStreamFromStreamWritable(streamWritable)`
+
+* `streamWritable` {stream.Writable}
+* Returns: {WritableStream}
+
+Creates and returns a {WritableStream} that wraps a {stream.Writable}.
+
+### Adapting Web Streams to Node.js streams
+
+#### `newStreamDuplexFromReadableWritablePair(pair[, options])`
+
+* `pair`: {Object}
+  * `readable` {ReadableStream}
+  * `writable` {WritableStream}
+* `options` {Object}
+  * `decodeStrings` {boolean} When `true`, the created {stream.Duplex}
+    will decode strings passed to it.
+  * `encoding` {string} The text encoding used by the created {stream.Duplex}.
+  * `highWaterMark` {number} The high water mark used by the created
+    {stream.Duplex}.
+  * `objectMode` {boolean} When `true`, the {stream.Duplex} will be put into
+    object mode.
+  * `signal` {AbortSignal} The {AbortSignal} passed into the created
+    {stream.Duplex}.
+* Returns: {stream.Duplex}
+
+Creates and returns a {stream.Duplex} that wraps a {ReadableStream} and
+{WritableStream} pair.
+
+#### `newStreamReadableFromReadableStream(readableStream[, options])`
+
+* `readableStream` {ReadableStream}
+* `options` {Object}
+  * `highWaterMark` {number} The high water mark used by the created
+    {stream.Readable}.
+  * `encoding` {string} The text encoding used by the created {stream.Readable}.
+  * `objectMode` {boolean} When `true`, the created {stream.Readable} will be
+    put into object mode.
+  * `signal` {AbortSignal} The {AbortSignal} passed into the created
+    {stream.Readable}.
+* Returns: {stream.Readable}
+
+Creates and returns a {stream.Readable} that wraps a {ReadableStream}.
+
+#### `newStreamWritableFromWritableStream(writableStream[, options])`
+
+* `writableStream` {WritableStream}
+* `options` {Object}
+  * `highWaterMark` {number} The high water mark used by the created
+    {stream.Writable}.
+  * `decodeStrings` {boolean} When `true`, the created {stream.Writable}
+    will decode strings passed to it.
+  * `objectMode` {boolean} When `true`, the created {stream.Writable} will be
+    put into object mode.
+  * `signal` {AbortSignal} The {AbortSignal} passed into the created
+    {stream.Writable}.
+* Returns: {stream.Writable}
+
+Creates and returns a {stream.Writable} that wraps a {WritableStream}.
+
 [Streams]: stream.md
 [WHATWG Streams Standard]: https://streams.spec.whatwg.org/

lib/internal/fs/promises.js

@@ -788,6 +788,8 @@ module.exports = {
     appendFile,
     readFile,
     watch,
+
+    kHandle,
   },
 
   FileHandle,