Assert that listener count decreases after a remove event.

lib/browser/rpc-server.js

@@ -146,7 +146,7 @@ const throwRPCError = function (message) {
   throw error
 }
 
-const rendererMissingErrorMessage = (meta, args, callIntoRenderer) => {
+const removeRemoteListenersAndLogWarning = (meta, args, callIntoRenderer) => {
   let message = `Attempting to call a function in a renderer window that has been closed or released.` +
     `\nFunction provided here: ${meta.location}`
 
@@ -218,7 +218,7 @@ const unwrapArgs = function (sender, args) {
           if (!sender.isDestroyed() && webContentsId === sender.getId()) {
             sender.send('ELECTRON_RENDERER_CALLBACK', meta.id, valueToMeta(sender, args))
           } else {
-            console.warn(rendererMissingErrorMessage(meta, args, callIntoRenderer))
+            console.warn(removeRemoteListenersAndLogWarning(meta, args, callIntoRenderer))
           }
         }
 

spec/api-ipc-spec.js

@@ -495,7 +495,7 @@ describe('ipc module', function () {
       assert.equal(w.listenerCount('test'), 0)
     })
 
-    it('shows a warning when a function is called in a destroyed renderer', (done) => {
+    it('detaches listeners subscribed to destroyed renderers, and shows a warning', (done) => {
       w = new BrowserWindow({
         show: false
       })
@@ -506,8 +506,10 @@ describe('ipc module', function () {
             'Function provided here: remote-event-handler.html:11:33',
             'Remote event names: remote-handler, other-remote-handler'
           ].join('\n')
-          const warningMessage = ipcRenderer.sendSync('try-emit-web-contents-event', w.webContents.id, 'remote-handler')
+          const {warningMessage, listenerCountBefore, listenerCountAfter} =
+            ipcRenderer.sendSync('try-emit-web-contents-event', w.webContents.id, 'remote-handler')
           assert.equal(warningMessage, expectedMessage)
+          assert.equal(listenerCountAfter, listenerCountBefore - 1)
           done()
         })
         w.webContents.reload()

spec/static/main.js

@@ -252,12 +252,20 @@ ipcMain.on('prevent-next-new-window', (event, id) => {
 
 ipcMain.on('try-emit-web-contents-event', (event, id, eventName) => {
   const consoleWarn = console.warn
-  let lastWarning = null
+  let warningMessage = null
   console.warn = (message) => {
-    lastWarning = message
+    warningMessage = message
   }
+
   const contents = webContents.fromId(id)
+  const listenerCountBefore = contents.listenerCount(eventName)
   contents.emit(eventName, {sender: contents})
-  event.returnValue = lastWarning
+  const listenerCountAfter = contents.listenerCount(eventName)
+
+  event.returnValue = {
+    warningMessage,
+    listenerCountBefore,
+    listenerCountAfter
+  }
   console.warn = consoleWarn
 })