I’m trying to use the performance.now() method, but using Delphi in TMS WEB Core.

In JavaScript I can do this:

const t0 = window.performance.now();

for (let i = 0; i < 100000; i++) {
  // some code
}

const t1 = window.performance.now();
console.log(`For Loop took ${t1 - t0} milliseconds.`);

I can see that in the Delphi IDE code completion, there is a window.performance which is of type TJSPerformance:

But I’m not sure how to use it and I can’t find any documentation on it. If I ctrl+left-click into TJSPerformance, it’s defined in the Web unit, but it’s empty:

TJSPerformance = class(TJSObject)
end;

But I’ve seen many things that appear empty when I ctrl+left-click, but then they still work and actually have things in it somewhere.

I’m not able to do window.Performance.now() in Delphi as that results in an error that says:

[Error] uIndex.pas(197): identifier not found “now”

I basically want to use this to calculate the execution time of Delphi code in TMS WEB Core.

So how does window.Performance and window.performance.now() work in Delphi?