ReferenceError: performance is not defined when using performance.now()

Question

I am getting an error ReferenceError: performance is not defined when trying to use performance.now() to measure the execution time of a function call:

export async function find(someId: string, ctx: context.IContext) {        try {         var t0 = performance.now();          var res = someModel.find(someId, ctx.cookies);          var t1 = performance.now();         console.log("Call to find took " + (t1 - t0) + " milliseconds.");          return res;       } catch (err) {         console.error(err);         throw err;       }     } 

Any ideas how I can fix this?

Answer 1

I know this is tagged front-end but if anyone comes across this looking for a node.js solution (like me), you need to first require performance from the perf_hooks module (available in node 8.5+).

const {performance} = require('perf_hooks'); const t0 = performance.now(); ...