Use queueMicrotask to isolate calls to user provided event handlers

packages/child/index.js

@@ -158,7 +158,7 @@ function iframeResizerChild() {
 
     sendTitle()
     initEventListeners()
-    setTimeout(onReady)
+    queueMicrotask(onReady)
 
     log('Initialization complete')
     log('---')
@@ -1244,6 +1244,12 @@ This version of <i>iframe-resizer</> can auto detect the most suitable ${type} c
   }
 
   function receiver(event) {
+    const { freeze } = Object
+    const { parse } = JSON
+    const parseFrozen = (data) => freeze(parse(data))
+
+    const notExpected = (type) => sendMsg(0, 0, `${type}Stop`)
+
     const processRequestFromParent = {
       init: function initFromParent() {
         initMsg = event.data
@@ -1282,10 +1288,9 @@ This version of <i>iframe-resizer</> can auto detect the most suitable ${type} c
         const msgBody = getData()
         log(`PageInfo received from parent: ${msgBody}`)
         if (onPageInfo) {
-          setTimeout(() => onPageInfo(JSON.parse(msgBody)))
+          queueMicrotask(() => onPageInfo(parse(msgBody)))
         } else {
-          // not expected, so cancel more messages
-          sendMsg(0, 0, 'pageInfoStop')
+          notExpected('pageInfo')
         }
         log(' --')
       },
@@ -1294,10 +1299,9 @@ This version of <i>iframe-resizer</> can auto detect the most suitable ${type} c
         const msgBody = getData()
         log(`ParentInfo received from parent: ${msgBody}`)
         if (onParentInfo) {
-          setTimeout(onParentInfo(Object.freeze(JSON.parse(msgBody))))
+          queueMicrotask(() => onParentInfo(parseFrozen(msgBody)))
         } else {
-          // not expected, so cancel more messages
-          sendMsg(0, 0, 'parentInfoStop')
+          notExpected('parentInfo')
         }
         log(' --')
       },
@@ -1306,7 +1310,7 @@ This version of <i>iframe-resizer</> can auto detect the most suitable ${type} c
         const msgBody = getData()
         log(`onMessage called from parent: ${msgBody}`)
         // eslint-disable-next-line sonarjs/no-extra-arguments
-        onMessage(JSON.parse(msgBody))
+        queueMicrotask(() => onMessage(parse(msgBody)))
         log(' --')
       },
     }

packages/core/index.js

@@ -659,8 +659,15 @@
     func = settings[iframeId][funcName]
 
     if (typeof func === 'function')
-      if (funcName === 'onClose' || funcName === 'onScroll') retVal = func(val)
-      else setTimeout(() => func(val))
+      if (funcName === 'onClose' || funcName === 'onScroll') {
+        try {
+          retVal = func(val)
+        } catch (error) {
+          // eslint-disable-next-line no-console
+          console.error(error)
+          warn(iframeId, `Error in ${funcName} callback`)
+        }
+      } else queueMicrotask(() => func(val))
     else
       throw new TypeError(
         `${funcName} on iFrame[${iframeId}] is not a function`,

spec/childSpec.js

@@ -195,22 +195,28 @@ define(['iframeResizerChild', 'jquery'], (mockMsgListener, $) => {
     })
 
     describe('inbound message', () => {
-      it('readyCallack', () => {
+      it('readyCallback', () => {
         expect(window.readyCalled).toEqual(true)
       })
 
-      it('message (String)', () => {
+      it('message (String)', (done) => {
         const msg = 'foo'
         mockMsgListener(createMsg('message:' + JSON.stringify(msg)))
 
-        expect(msgCalled).toBe(msg)
+        setTimeout(() => {
+          expect(msgCalled).toBe(msg)
+          done()
+        })
       })
 
-      it('message (Object)', () => {
+      it('message (Object)', (done) => {
         const msg = { foo: 'bar' }
         mockMsgListener(createMsg('message:' + JSON.stringify(msg)))
 
-        expect(msgCalled.foo).toBe('bar')
+        setTimeout(() => {
+          expect(msgCalled.foo).toBe('bar')
+          done()
+        })
       })
 
       it('reset 2', (done) => {