How to profile JavaScript

Note: this functionality may change in future

NativeScript runtime for Android provides __startCPUProfiler and __stopCPUProfiler global functions which help you to profile your JavaScript code. Here is an exameple

__startCPUProfiler("myprofile");
// some JavaScript code
__stopCPUProfiler("myprofile");

This will create a new file with the following naming scheme /sdcard/<package name>-<profile>-<timestamp>.cpuprofile.For example, if your application package name is org.nativescript.app1 then the output file will be named something like org.nativescript.app1-myprofile-19388793.672149.cpuprofile. Once you have a *.cpuprofile file you can pull it from the device with the following command

adb pull /sdcard/org.nativescript.app1-myprofile-19388793.672149.cpuprofile

Then you can load the file with Chrome DevTools.