Add specs for cookie changed event

spec/api-session-spec.js

@@ -179,6 +179,51 @@ describe('session module', function () {
         })
       })
     })
+
+    describe('changed events', function () {
+      it('emits an event when a cookie is set', function (done) {
+        session.defaultSession.cookies.on('changed', function cookieChanged(event, cookie, cause, removed) {
+          if (cookie.name !== 'foo') return
+
+          assert.equal(cookie.name, 'foo')
+          assert.equal(cookie.value, 'bar')
+          assert.equal(cause, 'explicit')
+          assert.equal(removed, false)
+          session.defaultSession.cookies.removeListener('changed', cookieChanged)
+          done()
+        })
+        session.defaultSession.cookies.set({
+          url: url,
+          name: 'foo',
+          value: 'bar'
+        }, function (error) {
+          if (error) return done(error)
+        })
+      })
+
+      it('emits an event when a cookie is removed', function (done) {
+        session.defaultSession.cookies.on('changed', function cookieChanged(event, cookie, cause, removed) {
+          if (cookie.name !== 'foo' || removed == false) return
+
+          assert.equal(cookie.name, 'foo')
+          assert.equal(cookie.value, 'bar')
+          assert.equal(cause, 'overwrite')
+          assert.equal(removed, true)
+          session.defaultSession.cookies.removeListener('changed', cookieChanged)
+          done()
+        })
+        session.defaultSession.cookies.set({
+          url: url,
+          name: 'foo',
+          value: 'bar'
+        }, function (error) {
+          if (error) return done(error)
+          session.defaultSession.cookies.remove(url, 'foo', function (error) {
+            if (error) return done(error)
+          })
+        })
+      })
+    })
   })
 
   describe('ses.clearStorageData(options)', function () {