Web-midi-test NPM

web-midi-test

Fake Web MIDI API for testing Web MIDI applications

Usage

Node.js

var WMT = require('web-midi-test');
navigator.requestMIDIAccess = WMT.requestMIDIAccess; // Node 22 and above, or
var navigator = { requestMIDIAccess: WMT.requestMIDIAccess }; // older versions
var performance = { now: WMT.now }; // if required...
// ...

HTML

<script src="node_modules/web-midi-test/wmt.js"></script>
// this will add an object named WMT into the global scope
// ...
if (typeof navigator.requestMIDIAccess == 'undefined') {
  navigator.requestMIDIAccess = WMT.requestMIDIAccess;
}
// ...

TypeScript

tsc myscript.ts --lib es2015,dom

import * as WMT from 'web-midi-test';
// ...

With JSDOM

With Zombie.js

With Puppeteer

With Playwright

API

MIDI access

function onSuccess() { console.log('Success!'); }
function onFail() { console.log('Fail!'); }

// normal scenario
WMT.requestMIDIAccess().then(onSuccess, onFail); // Success!
WMT.requestMIDIAccess({ sysex: true }).then(onSuccess, onFail); // Success!

// no sysex permission scenario
WMT.sysex = false;
WMT.requestMIDIAccess().then(onSuccess, onFail); // Success!
WMT.requestMIDIAccess({ sysex: true }).then(onSuccess, onFail); // Fail!

// no midi permission scenario
WMT.midi = false;
WMT.requestMIDIAccess().then(onSuccess, onFail); // Fail!

MIDI Source (Virtual MIDI-In)

var port = new WMT.MidiSrc('VIRTUAL MIDI-In');
port.connect();
port.emit([0x90, 0x40, 0x7f]);
//...
port.busy = true;  // "another application" captured the port
// Web MIDI can see the port, but can not connect to it
port.busy = false; // "another application" released the port
//...
port.disconnect();

MIDI Destination (Virtual MIDI-Out)

var port = new WMT.MidiDst('VIRTUAL MIDI-Out');
port.receive = function(msg) { console.log('received:', msg); };
port.connect();
//...
port.busy = true;  // "another application" captured the port
// Web MIDI can see the port, but can not connect to it
port.busy = false; // "another application" released the port
//...
port.disconnect();