Aragorn

A Simple Type Script Library, to track events in our JS code bases.

And easiest way to track performance of some UI/ BE event is to calculate the time taken from the starting and ending point of the event.

Aragorn helps the JS devs to carry out this easily in his/her code base by just asking to start and stop an event when needed and Aragorn the legendary tracer will do the rest and will either return the time elapsed for an event or will throw a cautionary error warning for the mortals to correct his/her request.

Its usage is very simple , import Aragorn wherever you want to avail his services.

import Aragorn from './Aragorn';

{
Aragorn.startTrace('CUSTOM_EVENT_NAME');
//code block you want to trace
}

{
//code block you want to trace
Aragorn.stopTrace('CUSTOM_EVENT_NAME',printEventDuration)
}

Note: Aragorn also takes a function when you ask him to stop the trace.

Aragorn will return details like event name and event duration for you to use.

function printEventDuration(traceObj: any) {
  if (traceObj) console.log('Event : ' + traceObj.key + ' Duration:' + traceObj.duration);
}

Use Cases

Use Case 1 : values of event name is given with delay

Aragorn.startTrace('CUSTOM_EVENT_1');
//add delay then stop
setTimeout(() => { Aragorn.stopTrace('CUSTOM_EVENT_1',printEventDuration)},2000);

Case 2 : values of event is given without any delay

Aragorn.startTrace('CUSTOM_EVENT_2');
//piece of code you want to track for time
Aragorn.stopTrace('CUSTOM_EVENT_2',printEventDuration)

Case 3 : clear all exisiting traces

Aragorn.clearAllTrace();

Case 4 : Log all event activity

Aragorn.enableLogs(true);

Case 5 : Pass Extra Properties with the events

let traceProperties = new Map();  
  
traceProperties.set('property1', 'value1');     
traceProperties.set('property2', 'www.androidiots.in');       


Aragorn.startTrace('CUSTOM_EVENT_WITH_MAP', traceProperties);
//add delay then stop
setTimeout(() => { Aragorn.stopTrace('CUSTOM_EVENT_WITH_MAP',printEventDurationAndMap)},2000);


function printEventDurationAndMap(traceObj){
  
  if(traceObj)
  console.log("Event : " +traceObj.key + " Duration:" + traceObj.duration);
  
  if(traceObj.properties)
  {
    traceObj.properties.forEach((value: string, key: string) => {
      console.log(key, value);
  });
  }
}

All the Use Cases are also available under samples/index.js

Edge Cases

Case 1 : event stop is called incorrectly before starting the trace

Aragorn.stopTrace('CUSTOM_EVENT_3',printEventDuration) //reference error will be thrown 
Aragorn.stopTrace(122,printEventDuration) //type error will be thrown

Case 2 : event start is is called multiple times before

Eg

let count = 5;
var myVar = setInterval(startIntervalTimer, 1000);

function startIntervalTimer() {
    if (--count === 0) {
    console.log('Stop Trace Called')
    Aragorn.stopTrace('CUSTOM_EVENT_4',printEventDuration);
    stopIntervalTimer();
    }
    else {
        console.log('Start trace started called ' + (5 - count) + ' time');
        Aragorn.startTrace('CUSTOM_EVENT_4');
    }
  }
  
  function stopIntervalTimer() {
    clearInterval(myVar);
  }

Case 3 : null is passed as key to start or stop trace

  Aragorn.startTrace(null); // Reference error will be thrown

  Aragorn.stopTrace(null);  // Reference error will be thrown