Function eventToHotkeyString

src/hotkey.ts:38–68

(
  event: KeyboardEvent,
  platform: string = navigator.platform
)

 * })
 */
export function eventToHotkeyString(
  event: KeyboardEvent,
  platform: string = navigator.platform
): NormalizedHotkeyString {
  const {ctrlKey, altKey, metaKey, shiftKey, key} = event
  const hotkeyString: string[] = []
  const modifiers: boolean[] = [ctrlKey, altKey, metaKey, shiftKey]

  for (const [i, mod] of modifiers.entries()) {
    if (mod) hotkeyString.push(modifierKeyNames[i])
  }

  if (!modifierKeyNames.includes(key)) {
    // MacOS outputs symbols when `Alt` is held, so we map them back to the key symbol if we can
    const altNormalizedKey =
      hotkeyString.includes('Alt') && matchApplePlatform.test(platform) ? macosSymbolLayerKeys[key] ?? key : key

    // MacOS outputs lowercase characters when `Command+Shift` is held, so we map them back to uppercase if we can
    const shiftNormalizedKey =
      hotkeyString.includes('Shift') && matchApplePlatform.test(platform)
        ? macosUppercaseLayerKeys[altNormalizedKey] ?? altNormalizedKey
        : altNormalizedKey

    // Some symbols can't be used because of hotkey string format, so we replace them with 'synthetic' named keys
    const syntheticKey = syntheticKeyNames[shiftNormalizedKey] ?? shiftNormalizedKey

    hotkeyString.push(syntheticKey)
  }

  return hotkeyString.join('+') as NormalizedHotkeyString
}

const modifierKeyNames: string[] = ['Control', 'Alt', 'Meta', 'Shift']