Merge de9c24b into feb759f

README.md

@@ -26,8 +26,12 @@ Destroy the given stream. In most cases, this is identical to a simple
      and add a listener to the `open` event to call `stream.close()` if it is
      fired. This is for a Node.js bug that will leak a file descriptor if
      `.destroy()` is called before `open`.
-  2. If the `stream` is not an instance of `Stream`, then nothing happens.
-  3. If the `stream` has a `.destroy()` method, then call it.
+  1. If the `stream` is not an instance of `Stream`, then nothing happens.
+  1. If the `stream` is a zlib stream, it will first call
+     `stream.destroy()` (if that function exists), followed by
+     `stream.close()` as that will correctly release the zlib handle from
+     memory.
+  1. If the `stream` has a `.destroy()` method, then call it.
 
 The function returns the `stream` passed in as the argument.
 

index.js

@@ -12,6 +12,7 @@
  */
 
 var ReadStream = require('fs').ReadStream
+var zlib = require('zlib')
 var Stream = require('stream')
 
 /**
@@ -37,13 +38,46 @@ function destroy (stream) {
     return stream
   }
 
+  if (stream instanceof zlib.Gzip ||
+      stream instanceof zlib.Gunzip ||
+      stream instanceof zlib.Deflate ||
+      stream instanceof zlib.DeflateRaw ||
+      stream instanceof zlib.Inflate ||
+      stream instanceof zlib.InflateRaw ||
+      stream instanceof zlib.Unzip) {
+    return destroyZlibStream(stream)
+  }
+
   if (typeof stream.destroy === 'function') {
     stream.destroy()
   }
 
   return stream
 }
 
+/**
+ * Destroy a zlib stream
+ *
+ * Zlib streams doesn't have a destroy function in Node.js 6. On top of that
+ * simply calling destroy on a zlib stream in Node.js 8+ will result in a
+ * memory leak. So until that is fixed, we need to call both close AND destroy.
+ *
+ * PR to fix memory leak: https://github.com/nodejs/node/pull/23734
+ *
+ * In Node.js 6+8, it's important that destroy is called before close as the
+ * stream would otherwise emit the error 'zlib binding closed'.
+ *
+ * @param {object} stream
+ * @private
+ */
+
+function destroyZlibStream (stream) {
+  if (typeof stream.destroy === 'function') stream.destroy()
+  if (typeof stream.close === 'function') stream.close()
+
+  return stream
+}
+
 /**
  * Destroy a ReadStream.
  *

test/test.js

@@ -2,6 +2,7 @@
 var assert = require('assert')
 var fs = require('fs')
 var net = require('net')
+var zlib = require('zlib')
 
 var destroy = require('..')
 
@@ -72,6 +73,41 @@ describe('destroy', function () {
       })
     })
   })
+
+  describe('zlib', function () {
+    var version = process.versions.node.split('.').map(function (n) {
+      return Number(n)
+    })
+    var preNode0_10 = version[0] === 0 && version[1] < 10
+    var types = ['Gzip', 'Gunzip', 'Deflate', 'DeflateRaw', 'Inflate', 'InflateRaw', 'Unzip']
+
+    types.forEach(function (type) {
+      var constructor = 'create' + type
+
+      it('should destroy a ' + type + ' stream created sync', function () {
+        var stream = zlib[constructor]()
+        destroy(stream)
+        if (preNode0_10) {
+          assert.strictEqual(stream._ended, true)
+        } else {
+          assert.strictEqual(stream._closed, true)
+        }
+      })
+
+      it('should destroy a ' + type + ' stream created async', function (done) {
+        var stream = zlib[constructor]()
+        setTimeout(function () {
+          destroy(stream)
+          if (preNode0_10) {
+            assert.strictEqual(stream._ended, true)
+          } else {
+            assert.strictEqual(stream._closed, true)
+          }
+          done()
+        }, 0)
+      })
+    })
+  })
 })
 
 function isdestroyed (stream) {