message: test: make pdf optional
diff: @@ -54,10 +54,10 @@ describe('Context Menus', () => {
  expect(browser.tabs.executeScript.calledWith({ file: sinon.match('youdao') })).toBeTruthy()
  })
  it('view_as_pdf', async () => {
  + browser.tabs.query.onFirstCall().returns(Promise.resolve([]))
  browser.contextMenus.onClicked.dispatch({ menuItemId: 'view_as_pdf' })
  await timer(0)
  - expect(browser.tabs.query.called).toBeTruthy()
  - expect(browser.tabs.create.calledWith({ url: sinon.match('pdf') })).toBeTruthy()
  + expect(browser.tabs.create.called).toBeTruthy()
  })
  it('search_history', async () => {
  browser.tabs.query.onFirstCall().returns(Promise.resolve([]))
  