WkWebView Crash loop on load only with --minifyjs or --prod Ionic compilation

[adamduren]

I am using Ionic along with the WkWebView as suggested in my application and ran into an error where the app would continually crash when using the --prod flag. It continually tries to reload the app which triggers the issue again. Usually after reloading anywhere from 3-10 times it resolves itself. I tried varying various ionic options and found --minifyjs to be the culprit.

It seems like there might be two issues. One is that the WkWebView should not crash as a result of minified JavaScript. The second question of possible issue is Uglify doing something it shouldn't be doing?

I suspect that this has something to do with loading / rendering a large amount of data from the backend (firebase) although I can not explain why it only happens when minified. When I remove the data fetch it no longer occurs. Large in this case is relative but it started happening when I started querying for over 200 items.

We need a way to disable WkWebView from trying to automatically recover from a crash or to be able to set a maximum retry limit as it's making a massive amount of queries and burning through quotas. I can stop this in development but we have customers in production with this issue.

As far as debugging goes I cannot see if there are any console entries as the app crashes before I am able to attach the Safari debugger. Logs are also not being streamed to my console if they are being produced. I have attacked the stack trace of the failing thread and well as some console output from xcode.

In my debugging I switched back to UIWebView which did not have this issue.

Relevant package.json entiries

"ionic": "3.19.1",
"ionic-angular": "^3.9.2",
"@ionic/app-scripts": "^3.1.8",
"cordova-ios": "^4.5.4",
"cordova-plugin-ionic-webview": "^1.1.16",

Stacktrace:

Thread 7 name:  WTF::AutomaticThread
Thread 7 Crashed:
0   JavaScriptCore                	0x000000018ab911b8 WTFCrashWithInfo+ 9925048 (int, char const*, char const*, int) + 0
1   JavaScriptCore                	0x000000018a574a4c JSC::DFG::AbstractInterpreter<JSC::DFG::InPlaceAbstractState>::executeEffects+ 3517004 (unsigned int, JSC::DFG::Node*) + 39036
2   JavaScriptCore                	0x000000018a566f74 JSC::DFG::CFAPhase::performBlockCFA+ 3460980 (JSC::DFG::BasicBlock*) + 728
3   JavaScriptCore                	0x000000018a56676c JSC::DFG::CFAPhase::run+ 3458924 () + 280
4   JavaScriptCore                	0x000000018a5664d4 bool JSC::DFG::runAndLog<JSC::DFG::CFAPhase>+ 3458260 (JSC::DFG::CFAPhase&) + 56
5   JavaScriptCore                	0x000000018a2a2248 bool JSC::DFG::runPhase<JSC::DFG::CFAPhase>+ 557640 (JSC::DFG::Graph&) + 48
6   JavaScriptCore                	0x000000018a665c38 JSC::DFG::Plan::compileInThreadImpl+ 4504632 () + 1956
7   JavaScriptCore                	0x000000018a664f64 JSC::DFG::Plan::compileInThread+ 4501348 (JSC::DFG::ThreadData*) + 644
8   JavaScriptCore                	0x000000018a7133ec JSC::DFG::Worklist::ThreadBody::work+ 5215212 () + 320
9   JavaScriptCore                	0x000000018ab95318 WTF::Function<void ()>::CallableWrapper<WTF::AutomaticThread::start(WTF::AbstractLocker const&)::$_0>::call+ 9941784 () + 360
10  JavaScriptCore                	0x000000018a22570c WTF::threadEntryPoint+ 46860 (void*) + 120
11  JavaScriptCore                	0x000000018a22564c WTF::wtfThreadEntryPoint+ 46668 (void*) + 84
12  libsystem_pthread.dylib       	0x00000001834802b4 _pthread_body + 308
13  libsystem_pthread.dylib       	0x0000000183480180 _pthread_body + 0
14  libsystem_pthread.dylib       	0x000000018347eb74 thread_start + 4

XCode Logs

2018-01-31 11:46:01.898798-0500 IonicApp[806:315416] Apache Cordova native platform version 4.5.3 is starting.
2018-01-31 11:46:01.900179-0500 IonicApp[806:315416] Multi-tasking -> Device: YES, App: YES
2018-01-31 11:46:01.919945-0500 IonicApp[806:315416] CDVWKWebViewEngine: trying to inject XHR polyfill
2018-01-31 11:46:01.986398-0500 IonicApp[806:315416] [MC] Lazy loading NSBundle MobileCoreServices.framework
2018-01-31 11:46:01.986643-0500 IonicApp[806:315416] [MC] Loaded MobileCoreServices.framework
2018-01-31 11:46:01.993397-0500 IonicApp[806:315416] CDVWKWebViewEngine will reload WKWebView if required on resume
2018-01-31 11:46:01.993533-0500 IonicApp[806:315416] Using Ionic WKWebView
2018-01-31 11:46:01.994142-0500 IonicApp[806:315416] [CDVTimer][console] 0.212073ms
2018-01-31 11:46:01.994396-0500 IonicApp[806:315416] [CDVTimer][handleopenurl] 0.130057ms
2018-01-31 11:46:01.997296-0500 IonicApp[806:315416] [CDVTimer][intentandnavigationfilter] 2.807975ms
2018-01-31 11:46:01.997550-0500 IonicApp[806:315416] [CDVTimer][gesturehandler] 0.130057ms
2018-01-31 11:46:02.040939-0500 IonicApp[806:315416] [CDVTimer][statusbar] 43.223977ms
2018-01-31 11:46:02.043696-0500 IonicApp[806:315416] [CDVTimer][keyboard] 2.407908ms
2018-01-31 11:46:02.057501-0500 IonicApp[806:315416] [CDVTimer][splashscreen] 13.637066ms
2018-01-31 11:46:02.057631-0500 IonicApp[806:315416] [CDVTimer][TotalPluginStartup] 63.753009ms
2018-01-31 11:46:03.767100-0500 IonicApp[806:315416] Ionic Native: deviceready event fired after 581 ms
2018-01-31 11:46:06.193721-0500 IonicApp[806:315500] [ProcessSuspension]  0x1c4670340 - ProcessAssertion() Unable to acquire assertion for process with PID 0
2018-01-31 11:46:07.682214-0500 IonicApp[806:315416] Ionic Native: deviceready event fired after 680 ms
2018-01-31 11:46:09.782389-0500 IonicApp[806:315501] [ProcessSuspension]  0x1c0275b40 - ProcessAssertion() Unable to acquire assertion for process with PID 0

...the deviceready and ProcessSuspension lines loop until for some reason reloading does not cause a crash

[hartherbert]

having the same issue using the --prod flag

[adamduren]

@hartherbert Does it work for you if you use ionic cordova run ios --aot --minifycss --optimizejs? I believe that's all of the prod flags minus --minifyjs. Trying to figure out of it's strictly uglifyjs or a combination of things.

[hartherbert]

It's hard to tell if it works with only those flags ionic cordova run ios --aot --minifycss --optimizejs because it doesnt fail everytime.
In my case I am using onic cordova run ios --aot --minifycss --release