Add test of sending Buffer

spec/api-ipc-spec.js

@@ -286,7 +286,7 @@ describe('ipc module', function () {
       ipcRenderer.send('message', obj)
     })
 
-    it('can send instance of Date', function (done) {
+    it('can send instances of Date', function (done) {
       const currentDate = new Date()
       ipcRenderer.once('message', function (event, value) {
         assert.equal(value, currentDate.toISOString())
@@ -295,6 +295,15 @@ describe('ipc module', function () {
       ipcRenderer.send('message', currentDate)
     })
 
+    it('can send instances of Buffer', function (done) {
+      var buffer = Buffer.from('hello')
+      ipcRenderer.once('message', function (event, message) {
+        assert.ok(buffer.equals(message))
+        done()
+      })
+      ipcRenderer.send('message', buffer)
+    })
+
     it('can send objects with DOM class prototypes', function (done) {
       ipcRenderer.once('message', function (event, value) {
         assert.equal(value.protocol, 'file:')