chord-chart-wasm

This package provides chord chart validation and transposition functionality.

It is written in Rust and has an accompanying library in Python. Used in vrslev/songbook — lyrics and chords webapp.

Example

Here's an example tests that describe ins and outs of the available functions:

import { expect, it } from "vitest";
import init, {
  transposeChart,
  validateChart,
  ValidationError,
} from "chord-chart-wasm";

it("works", async () => {
  await init();

  // that's a valid chart: | *chord-with-bass-note* *chord-without-accidental* | *chord* | *(end of the bar, then new bar ->)*
  // | *chord-with-accidental-and-symbols* |
  expect(validateChart("| A/E E | E | \n| C#m|")).toEqual(
    "| A/E E | E |\n| C#m |"
  );

  // and that's not a valid one: chords without stripes between lines of bars
  expect(() => validateChart("A/E E\nC#m")).toThrow(
    new ValidationError("BarLineShouldStartWithStripe", "A/E E")
  );

  expect(transposeChart("| A/E| E |\n| C#m|", "E", "Db")).toEqual(
    "| Gb/Db | Db |\n| Bbm |"
  );
});

Installation

Just npm i chord-chart-wasm. Works on both Node and browser.

Development

• npm i to install deps.
• npm run build to clean up, build wasm artifacts and package bundle.
• npm test to test the package.
• npm run build-test to build and test the package.
• npm run check-types to run tsc.

Also make sure to install pre-commit hooks (pre-commit install from the repository root).