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tinybench

Installation​

First install the plugin @codspeed/tinybench-plugin and tinybench (if not already installed):

npm install --save-dev @codspeed/tinybench-plugin tinybench

Usage​

Let's create a fibonacci function and benchmark it with tinybench and the CodSpeed plugin:

benches/bench.mjs
import { Bench } from "tinybench";
import { withCodSpeed } from "@codspeed/tinybench-plugin";

function fibonacci(n) {
  if (n < 2) {
    return n;
  }
  return fibonacci(n - 1) + fibonacci(n - 2);
}

const bench = withCodSpeed(new Bench());

bench
  .add("fibonacci10", () => {
    fibonacci(10);
  })
  .add("fibonacci15", () => {
    fibonacci(15);
  });

await bench.run();
console.table(bench.table());
tip

Noticed the .mjs extension? This is because we're using the ESM module format. Saving our file with the .js extension would have worked as well, but we would have needed to add "type": "module" to our package.json file to instruct Node.js to use the ESM module format.

If you're working with CommonJS modules, you can totally use the require syntax for importing the libraries.

Here, a few things are happening:

  • We create a simple recursive fibonacci function.

  • We create a new Bench instance with CodSpeed support by using the withCodSpeed helper. This step is critical to enable CodSpeed on your benchmarks.

  • We add two benchmarks to the suite and launch it, benching our fibonacci function for 10 and 15.

Now, we can run our benchmarks locally to make sure everything is working as expected:

And... Congrats🎉, CodSpeed is installed in your benchmarking suite! Locally, CodSpeed will fall back to tinybench since the instrumentation is only available in the CI environment for now.

You can now run those benchmarks in your CI to get consistent performance measurements.

Integrating into a bigger project, multiple benchmark files​

Often time you will not be writing your benchmarks in a single file. Indeed, it can become quite difficult to maintain a single file with all your benchmarks as your project grows.

info

You can find the source code for the following example in the examples of the codspeed-node repository. There are multiple examples available, for CJS, ESM, JavaScript, and TypeScript.

For these kind of situations, we recommend the following approach. Let's say you have a file structure like this, in a project with TypeScript:

.
├── bench
│   ├── fibo.bench.ts
│   ├── foobarbaz.bench.ts
│   └── index.bench.ts
├── package.json
├── src
│   ├── fibonacci.ts
│   └── foobarbaz.ts
└── tsconfig.json
  • The src directory contains the source code of the project. Here we have two files, fibonacci.ts and foobarbaz.ts.
  • The bench directory contains the benchmarks for the project. There is a file for each source file that defines benchmarks for it.
  • The bench/index.bench.ts file is the entry point for the benchmarks. It imports all the other benchmark files and runs them.
bench/fibo.bench.ts
import { Bench } from "tinybench";
import { iterativeFibonacci } from "../../src/fibonacci";

export function registerFiboBenchmarks(bench: Bench) {
  bench
    .add("test_iterative_fibo_10", () => {
      iterativeFibonacci(10);
    })
    .add("test_iterative_fibo_100", () => {
      iterativeFibonacci(100);
    });
}

Here we define a function that takes an instance of Bench as a parameter and then adds some benchmarks to it. This will allow us to add benchmarks to the same suite from multiple files.

bench/index.bench.ts
import { withCodSpeed } from "@codspeed/tinybench-plugin";
import { Bench } from "tinybench";
import { registerFiboBenchmarks } from "./fibo.bench";
import { registerFoobarbazBenchmarks } from "./foobarbaz.bench";

export const bench = withCodSpeed(new Bench());

(async () => {
  registerFiboBenchmarks(bench);
  registerFoobarbazBenchmarks(bench);

  await bench.run();
  console.table(bench.table());
})();

Here all the functions registering benchmarks are executed to import all the benchmarks from the different files.

To run the benchmarks, use the following command:

node -r esbuild-register bench/index.bench.ts
info

Check out the full for this example: with-typescript-cjs in the codspeed-node repository.

Running the benchmarks in your CI​

To generate performance reports, you need to run the benchmarks in your CI. This allows CodSpeed to detect the CI environment and properly configure the instrumented environment.

tip

If you want more details on how to configure the CodSpeed action, you can check out the Continuous Reporting section.

Here is an example of a GitHub Actions workflow that runs the benchmarks and reports the results to CodSpeed on every push to the main branch and every pull request:

.github/workflows/codspeed.yml
name: CodSpeed

on:
  push:
    branches:
      - "main" # or "master"
  pull_request:
  # `workflow_dispatch` allows CodSpeed to trigger backtest
  # performance analysis in order to generate initial data.
  workflow_dispatch:

jobs:
  benchmarks:
    name: Run benchmarks
    runs-on: ubuntu-latest
    steps:
      - uses: "actions/checkout@v4"
      - uses: "actions/setup-node@v3"
      - name: Install dependencies
        run: npm install
      - name: Run benchmarks
        uses: CodSpeedHQ/action@v3
        with:
          run: node benches/bench.mjs
          token: ${{ secrets.CODSPEED_TOKEN }}