Does Testcomplete only support basic html?
<div class="mat-input-infix mat-form-field-infix">
<mat-select class="mat-select ng-tns-c12-17 ng-tns-c7-13 TESTID_COMMONCONFIG_TIMEZONEAREA ng-pristine ng-valid ng-touched" role="listb...
Forum Discussion
TestComplete recognizes a number of different web control packages and such. Did a quick google search and the "mat" classes are Angular Material design components which, by default, TestComplete doesn't recognize "out of the box", at least not in any documentation that I can find.
This doesn't mean you are SOL, just means that you will need to get creative in automating those components. You won't be able to do the typical "ClickItem" kind of thing but might need to write custom code to operate with the identified DIV panels.
Documentation on supported web controls can be found at
https://support.smartbear.com/testcomplete/docs/app-testing/web/general/control-support.html
Specifically, for AngularUI, read
https://support.smartbear.com/testcomplete/docs/general-info/supported-technologies/controls/angularui.html