A JavaScript tool to compare the performance difference between different algorithms, functions or versions of the same code.

How it works ?

The CodeRunner class is used to group the code blocks, then execute them several times, while calculating the average execution time for each one.

Import and initialize an instance of the CodeRunner class.

const { CodeRunner } = require('@shvmerc/performance');
const runner = new CodeRunner();

Add the code blocks using the add method, you must enter the following parameters.

• id: Name or ID for the code block, must be unique.
• fn: The function that contains the code to be executed.

runner.add('Method 1', () => {
  const array: number[] = [];
  for (let i = 0; i <= 100; i++) {
    array.push(i);
  }
  return array;
});

runner.add('Method 2', () => {
  const array = Array(101);
  for (let i = 0; i <= 100; i++) {
    array[i] = i;
  }
  return array as number[];
});

runner.add('Method 3', () => {
  return Array.from({ length: 101 }, (_, index) => index);
});

runner.add('Method 4', () => {
  return Array(101).map((_, index) => index);
});

runner.add('Method 5', () => {
  return [...Array(101).keys()];
});

Run the comparison using the run method and passing the number of repetitions.

A larger number of repetitions results in a more accurate comparison, but can significantly increase the total duration.

const performances = runner.run(100000);

Now you can use the results as you wish, but the package includes a simple way to print the results into the console.

First, create a new instance of the PerformancePrinter class, you must enter the results directly as the constructor argument.

const { PerformancePrinter } = require('@shvmerc/performance');
const printer = new PerformancePrinter(performances);

Execute the print method to display a comparative graph of the results.

Multiple options are available to configure the output graph.

• options.target: Displays the percentage difference between the results and the target. By default, the target will be the lowest average result.
• options.sort: Sort the results, for 'default' by index and for 'ascending' or 'descending' by average time.
• options.highlight: Highlights selected code blocks in the results.

printer.print({
  target: 'Method 4',
  sort: 'ascending',
  highlight: {
    red: 'Method 2',
    green: 'Method 4',
  },
});