feat(keybindings): add mouse button support for mpv keybindings (#103)

src/settings/key-input.test.ts

@@ -5,6 +5,7 @@ import {
   buildMpvKeybindingConfigValue,
   createMpvKeybindingRows,
   keyboardEventToConfigKey,
+  mouseEventToConfigKey,
 } from './key-input';
 
 test('keyboardEventToConfigKey formats Electron accelerators from learned input', () => {
@@ -75,6 +76,23 @@ test('keyboardEventToConfigKey formats mpv key bindings from learned input', ()
   );
 });
 
+test('mouseEventToConfigKey formats mpv mouse buttons from learned input', () => {
+  assert.equal(
+    mouseEventToConfigKey(
+      { button: 3, ctrlKey: false, altKey: false, shiftKey: false, metaKey: false },
+      'dom-code',
+    ),
+    'MBTN_BACK',
+  );
+  assert.equal(
+    mouseEventToConfigKey(
+      { button: 4, ctrlKey: false, altKey: true, shiftKey: true, metaKey: false },
+      'dom-code',
+    ),
+    'Alt+Shift+MBTN_FORWARD',
+  );
+});
+
 test('MPV keybinding rows save default key moves as a disable plus replacement', () => {
   const defaults: Keybinding[] = [{ key: 'Space', command: ['cycle', 'pause'] }];
   const rows = createMpvKeybindingRows(defaults, []);