The Dart SDK comes with a profiling tool since version 1.4. It's still in development, so we're going to look at just the basic things. Observatory has a comfortable browser GUI that makes it easy to use for everyone. You're probably not going to spend much time profiling your apps unless you're working with large amounts of data or in a field where performance matters a lot (such as games). However, it's good to know that there's such tool and it's built right inside Dart's VM.

You can run the profiler for both the standalone Dart VM and web apps, but we'll take a look only at the standalone Dart VM, because we can easily run it from Dart Editor.

For this example, we'll reuse the fuzzy search code from Chapter 2, Practical Dart, and create a test CLI app that runs a few search queries:

import 'dart:io';
import 'dart:convert';
import '../../Chapter_02_doc_search/lib/FuzzySearch.dart';

main() {
  FuzzySearch fuzzy;
  
  void testSearch() {
    List testTerms...