Not as much in Jetbrains IDEs: it detects the string is HTML and highlighting, formatting, and mode-specific functionality all just work inside the string. In an Angular source file, all the template properties like "ng-if" autocomplete too, not sure if any code completion inside props works though (it doesn't with the AngularJS 1.x I just tested, but that's a different plugin that's probably less capable). Have to be careful about escaping the outermost quotes too if you use them in the template. So not exactly terrible, but still a little bit janky.