old_contents: """The test for the World clock sensor platform."""
  import unittest
  
  from homeassistant.setup import setup_component
  import homeassistant.util.dt as dt_util
  
  from tests.common import get_test_home_assistant
  
  
  class TestWorldClockSensor(unittest.TestCase):
      """Test the World clock sensor."""
  
      def setUp(self):
          """Set up things to be run when tests are started."""
          self.hass = get_test_home_assistant()
          self.time_zone = dt_util.get_time_zone("America/New_York")
  
      def test_time(self):
          """Test the time at a different location."""
          config = {"sensor": {"platform": "worldclock", "time_zone": "America/New_York"}}
          assert setup_component(self.hass, "sensor", config)
          self.hass.block_till_done()
          self.addCleanup(self.hass.stop)
  
          state = self.hass.states.get("sensor.worldclock_sensor")
          assert state is not None
  
          assert state.state == dt_util.now(time_zone=self.time_zone).strftime("%H:%M")
  
      def test_time_format(self):
          """Test time_format setting."""
          time_format = "%a, %b %d, %Y %I:%M %p"
          config = {
              "sensor": {
                  "platform": "worldclock",
                  "time_zone": "America/New_York",
                  "time_format": time_format,
              }
          }
          assert setup_component(self.hass, "sensor", config)
          self.hass.block_till_done()
          self.addCleanup(self.hass.stop)
  
          state = self.hass.states.get("sensor.worldclock_sensor")
          assert state is not None
  
          assert state.state == dt_util.now(time_zone=self.time_zone).strftime(
              time_format
          )
  
new_contents: """The test for the World clock sensor platform."""
  import pytest
  
  from homeassistant.setup import async_setup_component
  import homeassistant.util.dt as dt_util
  
  
  @pytest.fixture
  def time_zone():
      """Fixture for time zone."""
      return dt_util.get_time_zone("America/New_York")
  
  
  async def test_time(hass, time_zone):
      """Test the time at a different location."""
      config = {"sensor": {"platform": "worldclock", "time_zone": "America/New_York"}}
  
      assert await async_setup_component(
          hass,
          "sensor",
          config,
      )
      await hass.async_block_till_done()
  
      state = hass.states.get("sensor.worldclock_sensor")
      assert state is not None
  
      assert state.state == dt_util.now(time_zone=time_zone).strftime("%H:%M")
  
  
  async def test_time_format(hass, time_zone):
      """Test time_format setting."""
      time_format = "%a, %b %d, %Y %I:%M %p"
      config = {
          "sensor": {
              "platform": "worldclock",
              "time_zone": "America/New_York",
              "time_format": time_format,
          }
      }
  
      assert await async_setup_component(
          hass,
          "sensor",
          config,
      )
      await hass.async_block_till_done()
  
      state = hass.states.get("sensor.worldclock_sensor")
      assert state is not None
  
      assert state.state == dt_util.now(time_zone=time_zone).strftime(time_format)
  
subject: Rewrite worldclock unittest tests to pytest style test functions (#40922)