Testing And Benchmarking in JavaScript

Here’s the translation of the Go testing and benchmarking example to JavaScript, formatted in Markdown suitable for Hugo:

Testing is an important part of writing principled JavaScript programs. There are various testing frameworks available for JavaScript, but for this example, we’ll use Jest, which is a popular testing framework.

First, let’s implement the function we want to test:

function intMin(a, b) {
    if (a < b) {
        return a;
    }
    return b;
}

Now, let’s write some tests for this function:

const { intMin } = require('./intUtils');

describe('intMin', () => {
    test('basic test', () => {
        const result = intMin(2, -2);
        expect(result).toBe(-2);
    });

    test.each([
        [0, 1, 0],
        [1, 0, 0],
        [2, -2, -2],
        [0, -1, -1],
        [-1, 0, -1],
    ])('intMin(%i, %i) should return %i', (a, b, expected) => {
        const result = intMin(a, b);
        expect(result).toBe(expected);
    });
});

In this test file:

1. We import the intMin function from our intUtils.js file.
2. We use describe to group related tests together.
3. We create a basic test using the test function.
4. We use test.each to create a table-driven test, similar to the Go example.

To run these tests, you would typically use the Jest CLI:

$ jest

For benchmarking in JavaScript, we don’t have a built-in benchmarking tool like in Go. However, we can use libraries like Benchmark.js to perform benchmarks. Here’s an example of how you might set up a benchmark:

const Benchmark = require('benchmark');
const { intMin } = require('./intUtils');

const suite = new Benchmark.Suite;

suite.add('intMin', function() {
    intMin(1, 2);
})
.on('cycle', function(event) {
    console.log(String(event.target));
})
.run({ 'async': true });

To run this benchmark, you would execute this script with Node.js:

$ node benchmark.js
intMin x 76,543,209 ops/sec ±1.32% (89 runs sampled)

This output shows how many operations per second the intMin function can perform.

Remember that in JavaScript, the exact testing and benchmarking approaches can vary depending on the specific tools and frameworks you’re using. Jest is commonly used for testing in both Node.js and browser environments, while Benchmark.js is often used for performance benchmarking in Node.js.