Can call destroy twice

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v3.0.1 2018-02-05
+
+  * Can call `destroy` twice.
+
 ## v3.0.0 2018-02-04
 
   * New `setEncoding` and `destroy` methods.

lib/promise-duplex.js

@@ -126,10 +126,14 @@ class PromiseDuplex extends PromiseReadable /* and PromiseWritable */ {
   }
 
   destroy () {
-    this.readable.destroy()
-    delete this.readable
-    this.writable.destroy()
-    delete this.writable
+    if (this.readable) {
+      this.readable.destroy()
+      delete this.readable
+    }
+    if (this.writable) {
+      this.writable.destroy()
+      delete this.writable
+    }
   }
 }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "promise-duplex",
-  "version": "3.0.0",
+  "version": "3.0.1",
   "description": "Return promise for duplex stream",
   "main": "lib/promise-duplex.js",
   "typings": "lib/promise-duplex.d.ts",
@@ -23,8 +23,8 @@
     "node": ">=4.0.0"
   },
   "dependencies": {
-    "promise-readable": "^3.1.1",
-    "promise-writable": "^3.1.0"
+    "promise-readable": "^3.1.3",
+    "promise-writable": "^3.1.1"
   },
   "devDependencies": {
     "@types/node": "^9.4.0",

test/promise-duplex.js

@@ -95,7 +95,11 @@ Feature('Test promise-duplex module', () => {
       return promise.should.eventually.deep.equal(Buffer.from('chunk1'))
     })
 
-    And('stream can be destroyed', () => {
+    And('PromiseDuplex object can be destroyed', () => {
+      promiseDuplex.destroy()
+    })
+
+    And('PromiseDuplex object can be destroyed', () => {
       promiseDuplex.destroy()
     })
   })
@@ -377,6 +381,14 @@ Feature('Test promise-duplex module', () => {
       Then('promise is rejected', () => {
         return promise.should.be.rejectedWith(Error, 'boom')
       })
+
+      And('PromiseDuplex object can be destroyed', () => {
+        promiseDuplex.destroy()
+      })
+
+      And('PromiseDuplex object can be destroyed', () => {
+        promiseDuplex.destroy()
+      })
     })
 
     Scenario(`Wait for ${event} from stream with error emitted before method`, () => {