removing an eventListener on abort.

Author: martinheidegger

index.js

@@ -525,7 +525,9 @@ class Stream extends EventEmitter {
         if (opts.signal.aborted) {
           throw new Error('Stream aborted.')
         }
-        opts.signal.addEventListener('abort', abort.bind(this))
+        const handler = abort.bind(this)
+        this._clearSignal = clearSignal.bind(null, opts.signal, handler)
+        opts.signal.addEventListener('abort', handler)
       }
     }
   }
@@ -571,6 +573,9 @@ class Stream extends EventEmitter {
         this._writableState.updateNextTick()
       }
       this._predestroy()
+      if (this._clearSignal !== undefined) {
+        this._clearSignal()
+      }
     }
   }
 
@@ -976,6 +981,10 @@ function abort () {
   this.destroy(new Error('Stream aborted.'))
 }
 
+function clearSignal (signal, handler) {
+  signal.removeEventListener('abort', handler)
+}
+
 module.exports = {
   pipeline,
   pipelinePromise,

test/async-iterator.js

@@ -158,6 +158,8 @@ tape('using abort controller', async function (t) {
     return r
   }
   const controller = new AbortController()
+  let removeCalled = false
+  beforeFn(controller.signal, 'removeEventListener', () => { removeCalled = true })
   const inc = []
   setTimeout(() => controller.abort(), 10)
   try {
@@ -167,8 +169,17 @@ tape('using abort controller', async function (t) {
   } catch (err) {
     t.same(err.message, 'Stream aborted.')
   }
+  t.same(removeCalled, true)
   t.same(inc, [0])
   t.end()
+
+  function beforeFn (obj, fnName, handler) {
+    const orig = obj[fnName]
+    obj[fnName] = function () {
+      handler.apply(this, arguments)
+      orig.apply(this, arguments)
+    }
+  }
 })
 tape('using aborted abort controller', async function (t) {
   const controller = new AbortController()