Add addAbortSignal support (#18)

Author: yassernasc

index.d.ts

@@ -1,5 +1,6 @@
 import EventEmitter, { EventMap } from 'bare-events'
 import Buffer, { BufferEncoding } from 'bare-buffer'
+import { AbortSignal } from 'bare-abort-controller'
 
 type StreamEncoding = BufferEncoding | 'buffer'
 
@@ -191,6 +192,8 @@ declare namespace Stream {
   export function isWritable(stream: Stream): boolean
 
   export function getStreamError(stream: Stream, opts?: { all?: boolean }): Error | null
+
+  export function addAbortSignal<S extends Stream>(signal: AbortSignal, stream: S): S
 }
 
 export = Stream

index.js

@@ -27,6 +27,17 @@ exports.isWritable = function isWritable(stream) {
 
 exports.getStreamError = stream.getStreamError
 
+exports.addAbortSignal = function addAbortSignal(signal, stream) {
+  function onAbort() {
+    stream.destroy(signal.reason)
+  }
+
+  if (signal.aborted) onAbort()
+  else signal.addEventListener('abort', onAbort)
+
+  return stream
+}
+
 exports.Stream = exports
 
 exports.Readable = class Readable extends stream.Readable {

package.json

@@ -41,17 +41,22 @@
     "teex": "^1.0.1"
   },
   "devDependencies": {
+    "bare-abort-controller": "^1.1.0",
     "bare-buffer": "^3.0.0",
     "bare-events": "^2.5.4",
     "brittle": "^3.5.2",
     "prettier": "^3.3.3",
     "prettier-config-holepunch": "^2.0.0"
   },
   "peerDependencies": {
+    "bare-abort-controller": "*",
     "bare-buffer": "*",
     "bare-events": "*"
   },
   "peerDependenciesMeta": {
+    "bare-abort-controller": {
+      "optional": true
+    },
     "bare-buffer": {
       "optional": true
     },

test/basic.js

@@ -1,4 +1,6 @@
 const test = require('brittle')
+const AbortController = require('bare-abort-controller')
+
 const {
   Stream,
   Readable,
@@ -10,7 +12,8 @@ const {
   isErrored,
   isReadable,
   isWritable,
-  duplexPair
+  duplexPair,
+  addAbortSignal
 } = require('..')
 
 test('default export', (t) => {
@@ -735,4 +738,16 @@ test('async disposable', async (t) => {
   t.ok(writable.destroyed)
 })
 
+test('addAbortSignal', (t) => {
+  t.plan(1)
+
+  const controller = new AbortController()
+
+  const stream = addAbortSignal(controller.signal, new Readable())
+
+  finished(stream, (err) => t.is(err.message, 'The operation was aborted'))
+
+  controller.abort()
+})
+
 function noop() {}