Instrumentation profiling for the NativeScript framework

To use the tool first make sure you have everything in source control. The instrumentation may brake stuff.

Installation:

npm install nativescript-dev-fondue

Instrument the JavaScript. The following will rewrite the .js files in place without taking backups. You can remove the node_modules folder and reinstall modules from npm. For the app folder you may consider git init, git commit, and git reset --hard after you are done profiling.

To instrument files, at the root of your app use:

./node_modules/.bin/nsfondue "node_modules/tns-core-modules/**/*.js"
./node_modules/.bin/nsfondue "app/**/*.js"

Try not to instrument the fondue itself.

In your app/app.js add the following require as a first statement:

var calltree = require('nativescript-dev-fondue/tracers/calltree');

Avoid profiling large calltrees since output is now transfered through the console output to the host machine and may be slow. To start tracing execute the following in your app (on button tap?):

calltree.start();

To end the trace and dump the output call:

calltree.stop();

When you are ready with the installation and have placed the instrumentation start/stop calls run:

tns run ios | ./node_modules/.bin/calltreefilter log.js

The calltreefilter will redirect trace console logs to the logfile.js leaving other logs in the terminal. Open logfile.js with VSCode, you should be able to use codefolding to navigate through calls.

In the log.js you should see traces such as:

// } missing start time for: Observable.notify node_modules/tns-core-modules/data/observable/observable.js:138:34~158:5
// } missing start time for: Observable._emit node_modules/tns-core-modules/data/observable/observable.js:170:33~176:5
// } missing start time for: ActionItem._raiseTap node_modules/tns-core-modules/ui/action-bar/action-bar-common.js:317:37~319:5
// } missing start time for: TapBarItemHandlerImpl.tap node_modules/tns-core-modules/ui/action-bar/action-bar.ios.js:229:42~234:5
// offset: 787066328.2049471
DataSource.tableViewCellForRowAtIndexPath() { // node_modules/tns-core-modules/ui/list-view/list-view.ios.js:58:58~72:5
  // start:    0ms
  ListView._prepareCell() { // node_modules/tns-core-modules/ui/list-view/list-view.ios.js:265:38~300:5
    // start:    0.08081090450286865ms
    get view() { // node_modules/tns-core-modules/ui/list-view/list-view.ios.js:31:13~33:9
      // start:    0.08956897258758545ms
      // end:      0.09389388561248779ms
    } // duration: 0.004324913024902344ms
    notifyForItemAtIndex() { // node_modules/tns-core-modules/ui/list-view/list-view.ios.js:39:0~43:1
      // start:    0.10458683967590332ms
      Observable.notify() { // node_modules/tns-core-modules/data/observable/observable.js:138:34~158:5
        // start:    0.1276949644088745ms
        Observable._getEventList() { // node_modules/tns-core-modules/data/observable/observable.js:177:41~187:5
          // start:    0.13662993907928467ms
          // end:      0.1387479305267334ms
        } // duration: 0.0021179914474487305ms
        // end:      0.13974297046661377ms
      } // duration: 0.012048006057739258ms
      // end:      0.14091193675994873ms
    } // duration: 0.03632509708404541ms