message: fix(selection): fix undefined detection
diff: @@ -121,7 +121,7 @@ export function getDefaultSelectionInfo (extra: Partial<SelectionInfo> = {}): Se
  }
  export function isSameSelection (a: SelectionInfo, b: SelectionInfo) {
  - return a.text === b.text && a.context === b.context
  + return a && b && a.text === b.text && a.context === b.context
  }
  export function getSelectionInfo (): SelectionInfo {
  