[BUG] Application Insights reports 'not_specified' to Azure when tracking unhandled browser exception

[PieterWillemen]

Description/Screenshot
Application Insights has automatic exception tracking enabled by default.
However, it seems to assume that the exception is always of type Error.
If the exception is simply a string, the trackException itself fails, throws an exception with message 'not_specified'.

Steps to Reproduce
Here is my setup:

import { DebugPlugin } from '@microsoft/applicationinsights-debugplugin-js';
import { ApplicationInsights } from '@microsoft/applicationinsights-web'

// Initialize AppInsights
const toTrack = [
	'trackEvent',
	'trackPageView',
	'trackPageViewPerformance',
	'trackException',
	'trackTrace',
	'trackMetric',
	'trackDependencyData',
	'throwInternal',        // called when a message is logged internally
	'logInternalMessage',   // called when a message is logged internally
	'triggerSend',          // called when data is queued to be sent to the server
	'_sender',              // called when data is sent to the server
];
const debugPluginInstance = new DebugPlugin();
const applocation = this.AppLocation;
const pageName = EAppLocationPage[applocation.Page];
const appInsights = new ApplicationInsights({
	config: {
		connectionString: (window as any).appInsightsConfig.connectionString,
		extensions: [debugPluginInstance],
		extensionConfig: {
			[DebugPlugin.identifier]: {
				trackers: toTrack
			}
		},
		disableExceptionTracking: false,
		enableDebug: false,
		loggingLevelConsole: 2, //0: off, 1: Critical errors only, 2: Everything(errors & warnings)
		loggingLevelTelemetry: 2, //0: off, 1: Critical errors only, 2: Everything(errors & warnings)
		enableRequestHeaderTracking: true,
		enableResponseHeaderTracking: true,
		correlationHeaderExcludedDomains: ['*.queue.core.windows.net']
	}
});
appInsights.setAuthenticatedUserContext((window as any).appInsightsConfig.authenticatedUserContext);
appInsights.addTelemetryInitializer((x) => {
	x.tags!['ai.operation.name'] = 'Full_Load/' + pageName;
});
appInsights.loadAppInsights();

When I throw a dummy exception with simply a string message in the console to test AI's auto trackException, this is what AI does:
(Stacktrace shown by using the @microsoft/applicationinsights-debugplugin-js plugin.)

It seems that AI then itself fails, as it does not expect a string, but an Error.
This it what is then reported to Azure:

AnalyticsPlugin/</_self[_DynamicConstants__WEBPACK_IMPORTED_MODULE_1__._DYN_SEND_EXCEPTION_INTER13]@https://localhost:44385/js/ViewModels/patientsViewModel.min.js?v=PVKRkSfmexWSsx2UaNtVhIFEkwUYJoTDiuQ6OoT7Tyw:15684:224
AnalyticsPlugin/</_self.trackException@https://localhost:44385/js/ViewModels/patientsViewModel.min.js?v=PVKRkSfmexWSsx2UaNtVhIFEkwUYJoTDiuQ6OoT7Tyw:15703:138
dynProtoProxy@https://localhost:44385/js/ViewModels/patientsViewModel.min.js?v=PVKRkSfmexWSsx2UaNtVhIFEkwUYJoTDiuQ6OoT7Tyw:33706:29
_createFunctionHook/<@https://localhost:44385/js/ViewModels/patientsViewModel.min.js?v=PVKRkSfmexWSsx2UaNtVhIFEkwUYJoTDiuQ6OoT7Tyw:26241:119
_createProxyFunction/<@https://localhost:44385/js/ViewModels/patientsViewModel.min.js?v=PVKRkSfmexWSsx2UaNtVhIFEkwUYJoTDiuQ6OoT7Tyw:25946:112
@debugger eval code:1:20

If I throw an exception in code of type Error and catch it myself to manually call trackException(),

try {
	throw new Error('TESTPIETER FULL');
}
catch (error) {
	if (error instanceof Error) {
		appInsights.trackException({
			exception: error
		});
	} else {
		appInsights.trackException({
			exception: new Error(error as string)
		});
	}
}

then I see the following:

And the error is correctly reported to Azure:

So, to me, it seems that AI exception tracking does not work correctly out of the box.
Currently, I would need to override the current global exception handler of the browser, to convert a string exception to an Error and call trackException() manually.
This should be done by AI itself out of the box.

• OS/Browser: Any browser
• SDK Version [e.g. 22]: 2.8.9
• How you initialized the SDK: npm

[PieterWillemen]

I found a related issue here, where it is recommended to use the correct syntax when calling trackException().
#1006

But the actual issue is not solved, i.e. AI itself calls trackException() with a string.

[PieterWillemen]

This issue also rises here:
OfficeDev/microsoft-teams-library-js#577

[MSNev]

We "should" be handling string "exceptions" and we have specific tests and code to handle this.

But at least on looking at the code it does appear that when using the snippet a "string" won't necessarily be handled (it falls back to window.event so it will work on some browsers).

For the scenario provided (using NPM) this should be working as it should come through this hook for the window.onerror https://github.com/microsoft/ApplicationInsights-JS/blob/master/extensions/applicationinsights-analytics-js/src/JavaScriptSDK/AnalyticsPlugin.ts#L699-L706 so it should "not" be calling trackException with a string value (the snippet onerror does look like this will happen)

[PieterWillemen]

This is what Application Insights reports as browser exceptions on our production environment:

As you can see on row 1, 3 and 6 'not_specified' is being reported.
Some errors like Uncaught TypeError or Uncaught SyntaxError are being successfully reported.

[MSNev]

Just a note to inform that this issue is not forgotten, but due to scheduling conflicts, release lockdowns and holidays it's probably going to be early next year (2023) before I can carve out a decent amount of time to understand why strings are not always supported... I suspect that we will need to move the current string detecting code a little deeper in the stack.

[MSNev]

Allocating to the next release, but there is a risk (depending on the size of any required change) that it may not make this release.

[PieterWillemen]

Great, thanks for following up!

[MSNev]

Ok, I've tried 4 scenarios

• Just call throw "string error" -> resulted in the window.onerror to get called (Chromium based Edge) with an Error with the message set as the string -- works
• Directly call trackException(theError: IExceptionTelemetry) with a string as the exception value -- works when called directly or in a catch with the caught string. See here for the definition of the trackException arguments
• Directly call trackException("string value") -- resulting in what looks like your scenario Error being reported in the sendExceptionInternal as it wraps the provided first object (which is supposed to be an IExceptionTelemetry object) in an error -- This is considered to be an invalid usage of the API

    <button onclick="javascript: throw 'String Error'">Throw String Exception</button>
    <button onclick="javascript: appInsights.trackException({ exception: 'String Error' })"">trackException with String as the exception</button>
    <button onclick="javascript: try { throw 'String Error'; } catch(e) { appInsights.trackException({exception: e})}">trackException with try / catch</button>
    <button onclick="javascript: appInsights.trackException('String Error')"">trackException with String</button>

So while I could instead use our helper dumpObj() function to dump the object as theError instead of creating a new Error instance, there could still be other issues as the rest of the code is still attempting to use the first argument as an iExceptionTelemetry instance...

So you "should" be able to just use the following

try {
	throw 'TESTPIETER FULL';
}
catch (error) {
   appInsights.trackException({
	exception: error
   });
}

or just let the exception bubble up to the window.onerror handler.

Here is a screendump of the appInsights.trackException("String Error") version

For the one where I let it bubble to the window.onerror

And finally with appInsights.trackexception({ exception: "String Error" }), this is also the same for the try / catch example

The screen dumps where taken using F12 dev tools with the breakpoint @

ApplicationInsights-JS/extensions/applicationinsights-analytics-js/src/JavaScriptSDK/AnalyticsPlugin.ts

Line 427 in 65fddb1

_self.core.track(telemetryItem);

this is after we have created the envelope (the event detail) but before we send it off for batching.

Shorter answer
Please call trackException with an object that conforms to the IExceptionTelemetry interface.

[PieterWillemen]

I just figured out that in 1 place we were in fact using trackException with the wrong type of parameter.

Although this will not be the cause of all of our errors.

[MSNev]

The PR that I've just pushed in (so it will be in the next release) provides a "fallback" cases for cases where someone passes a non-IExceptionTelemetry (doesn't contain an error or exception object) to attempt to convert to provide more information.

This has test coverage and appears to now be handling strings or Error instances directly (as well as null / undefined which should be the only cases for the "not_specified" now)

[PieterWillemen]

Great!

[github-actions]

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