[BUG] AppInsights stub methods captured incorrect method names in the closure

[chenxinyanc]

Description/Screenshot

ApplicationInsights-JS/AISKU/snippet/snippet.js

Lines 225 to 240 in 5cb9e44

	function _createMethods(methods) {
	while (methods.length) {
	var name = methods.pop();
	// Define a temporary method that queues-up a the real method call
	appInsights[name] = function () {
	// Capture the original arguments passed to the method
	var originalArguments = arguments;
	if (!loadFailed) { // If we have detected that the main script failed to load then stop queuing events that will never be processed
	// Queue-up a call to the real method
	appInsights.queue.push(function () {
	// Invoke the real method with the captured original arguments
	appInsights[name].apply(appInsights, originalArguments);
	});
	}
	};
	}

Note the statement on L227:

var name = methods.pop();

Since var spans the variable scope to the containing function (i.e. _createMethods), the value of this variable gets replaced among each iteration of the while loops.

This causes all the appInsights.[method] calls before ai.2.js has loaded incorrectly forwarded as appInsights.trackEvent calls.

Steps to Reproduce
Copy-paste all the code in snippet.js, or its minimized version on README.md. Then follows the code. Ensure the following code is executed before ai.2.js has been downloaded.

appInsights.addTelemetryInitializer(function (e) { /* dummy */ } );

When running the code, you will find there are 2 trackEvent calls to the actual appInsights object, making 2 extra (invalid) event traces.

• OS/Browser:
• SDK Version [e.g. 22]: v2
• How you initialized the SDK: with snippet (snippet.js)

Expected behavior
I should have telemetry initializer set up. And there should be trackPageView called so I should have its telemetry.

Additional context
Add any other context about the problem here.

[MSNev]

NICE CATCH! - the issue is on line 234 as you identified where it's using effectively the last popped name!

[MSNev]

Reopening for release tracking

[MSNev]

Release is now fully deployed

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.