Work In Progress: Testing using web-midi-test

dist/cjs/webmidi.cjs.d.ts

@@ -5570,6 +5570,7 @@ declare class WebMidi extends EventEmitter {
     sysex?: boolean;
     validation?: boolean;
     software?: boolean;
+    requestMIDIAccessFunction?: Function;
   }): Promise<WebMidi>;
 
   /**

dist/esm/webmidi.esm.d.ts

@@ -5570,6 +5570,7 @@ declare class WebMidi extends EventEmitter {
     sysex?: boolean;
     validation?: boolean;
     software?: boolean;
+    requestMIDIAccessFunction?: Function;
   }): Promise<WebMidi>;
 
   /**

package.json

@@ -136,6 +136,7 @@
     "sinon-browser-only": "^1.12.1",
     "system-commands": "^1.1.7",
     "test-value": "^3.0.0",
-    "util": "^0.12.4"
+    "util": "^0.12.4",
+    "web-midi-test": "^1.1.9"
   }
 }

src/WebMidi.js

@@ -218,6 +218,11 @@ class WebMidi extends EventEmitter {
    * @param [options.software=false] {boolean} Whether to request access to software synthesizers on
    * the host system. This is part of the spec but has not yet been implemented by most browsers as
    * of April 2020.
+   * 
+   * @param [options.requestMIDIAccessFunction] {function} A custom function to use to return 
+   * the MIDIAccess object. This is useful if you want to use a polyfill for the Web MIDI API 
+   * or if you want to use a custom implementation of the Web MIDI API - probably for testing
+   * purposes.
    *
    * @async
    *
@@ -360,9 +365,15 @@ class WebMidi extends EventEmitter {
 
     // Request MIDI access (this iw where the prompt will appear)
     try {
-      this.interface = await navigator.requestMIDIAccess(
-        {sysex: options.sysex, software: options.software}
-      );
+      if (typeof options.requestMIDIAccessFunction === "function") {
+        this.interface = await options.requestMIDIAccessFunction(
+          {sysex: options.sysex, software: options.software}
+        );
+      } else {
+        this.interface = await navigator.requestMIDIAccess(
+          {sysex: options.sysex, software: options.software}
+        );
+      }
     } catch(err) {
       errorEvent.error = err;
       this.emit("error", errorEvent);

test/Forwarder.test.js

@@ -1,26 +1,29 @@
 const expect = require("chai").expect;
 const {Message, WebMidi, Note, Forwarder} = require("../dist/cjs/webmidi.cjs.js");
-const midi = require("midi");
+const WMT = require("web-midi-test");
 
 // The virtual port is an "external" device so an input is seen as an output by WebMidi. To avoid
 // confusion, the naming scheme adopts WebMidi's perspective.
-let VIRTUAL_OUTPUT = new midi.Input();
 let VIRTUAL_OUTPUT_NAME = "Virtual Output";
+let VIRTUAL_OUTPUT = new WMT.MidiDst(VIRTUAL_OUTPUT_NAME);
+/** @type {import("../dist/cjs/webmidi.cjs.js").Output} */
 let WEBMIDI_OUTPUT;
 
+function noop() {}
+
 describe("Forwarder Object", function() {
 
   before(function () {
-    VIRTUAL_OUTPUT.openVirtualPort(VIRTUAL_OUTPUT_NAME);
-    VIRTUAL_OUTPUT.ignoreTypes(false, false, false); // enable sysex, timing & active sensing
+    VIRTUAL_OUTPUT.connect();
+    // VIRTUAL_OUTPUT.ignoreTypes(false, false, false); // enable sysex, timing & active sensing
   });
 
   after(function () {
-    VIRTUAL_OUTPUT.closePort();
+    VIRTUAL_OUTPUT.disconnect();
   });
 
   beforeEach("Check support and enable WebMidi.js", async function () {
-    await WebMidi.enable({sysex: true});
+    await WebMidi.enable({sysex: true, requestMIDIAccessFunction: WMT.requestMIDIAccess});
     WEBMIDI_OUTPUT = WebMidi.getOutputByName(VIRTUAL_OUTPUT_NAME);
   });
 
@@ -97,15 +100,15 @@ describe("Forwarder Object", function() {
       const data = [0x90, 64, 127];
       const msg = new Message(data);
       const forwarder = new Forwarder(WEBMIDI_OUTPUT);
-      VIRTUAL_OUTPUT.on("message", assert);
+      VIRTUAL_OUTPUT.receive = assert;
 
       // Act
       forwarder.forward(msg);
 
       // Assert
-      function assert(deltaTime, message) {
+      function assert(message) {
         expect(message).to.have.ordered.members(msg.data);
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         done();
       }
 
@@ -119,19 +122,19 @@ describe("Forwarder Object", function() {
       const msg = new Message(data);
       const forwarder = new Forwarder(WEBMIDI_OUTPUT);
       forwarder.suspended = true;
-      VIRTUAL_OUTPUT.on("message", assert);
+      VIRTUAL_OUTPUT.receive = assert;
 
       // Act
       forwarder.forward(msg);
 
       const id = setTimeout(() => {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         done();
       }, 250);
 
       // Assert
       function assert(deltaTime, message) {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         clearTimeout(id);
         done(new Error("Callback should not have been triggered. " + message));
       }
@@ -147,11 +150,11 @@ describe("Forwarder Object", function() {
       const msg4 = new Message([0x9F, 64, 127]); // note on on ch. 16
       const channel = 10;
       const forwarder = new Forwarder(WEBMIDI_OUTPUT, {channels: channel});
-      VIRTUAL_OUTPUT.on("message", assert);
+      VIRTUAL_OUTPUT.receive = assert;
 
       // Act
       const id = setTimeout(() => {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         done();
       }, 250);
 
@@ -162,7 +165,7 @@ describe("Forwarder Object", function() {
 
       // Assert
       function assert(deltaTime, message) {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         clearTimeout(id);
         done(new Error("Callback should not have been triggered. " + message));
       }
@@ -182,11 +185,11 @@ describe("Forwarder Object", function() {
         0xD0
       ];
       const forwarder = new Forwarder(WEBMIDI_OUTPUT, {types: target.name});
-      VIRTUAL_OUTPUT.on("message", assert);
+      VIRTUAL_OUTPUT.receive = assert;
 
       // Act
       const id = setTimeout(() => {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         done();
       }, 250);
 
@@ -196,7 +199,7 @@ describe("Forwarder Object", function() {
 
       // Assert
       function assert(deltaTime, message) {
-        VIRTUAL_OUTPUT.removeAllListeners();
+        VIRTUAL_OUTPUT.receive = noop;
         clearTimeout(id);
         done(new Error("Callback should not have been triggered. " + message));
       }