Refactoring, added tests

###Fix
# In light of submitting this as a pull request to the core of HA there have been some refactoring changes to comply with HA's style requirements
#Sensor names now moved to strings file to allow for translations
#Coordinator now properly handles multiple devices
#Spelling of signal strength sensor corrected

###Feature
#Tests added

tests/test_init.py

@@ -0,0 +1,136 @@
+"""Test Owlet init."""
+from __future__ import annotations
+
+from unittest.mock import patch
+
+from pyowletapi.exceptions import (
+    OwletAuthenticationError,
+    OwletConnectionError,
+    OwletDevicesError,
+    OwletError,
+)
+
+from homeassistant.components.owlet.const import (
+    CONF_OWLET_EXPIRY,
+    CONF_OWLET_REFRESH,
+    DOMAIN,
+)
+from homeassistant.config_entries import ConfigEntryState
+from homeassistant.const import CONF_API_TOKEN, CONF_REGION, CONF_USERNAME, Platform
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import device_registry as dr, entity_registry as er
+
+from . import async_init_integration
+
+PLATFORMS: list[Platform] = [Platform.BINARY_SENSOR, Platform.SENSOR]
+
+
+async def test_async_setup_entry(hass: HomeAssistant) -> None:
+    """Test setting up entry."""
+    entry = await async_init_integration(hass)
+
+    assert entry.state == ConfigEntryState.LOADED
+
+    device_registry = dr.async_get(hass)
+
+    device_entry = device_registry.async_get_or_create(
+        config_entry_id=entry.entry_id, identifiers={(DOMAIN, "SERIAL_NUMBER")}
+    )
+
+    assert device_entry.name == "Owlet Baby Care Sock"
+
+    entity_registry = er.async_get(hass)
+
+    entities = er.async_entries_for_device(entity_registry, device_entry.id)
+
+    assert len(entities) == 8
+
+    await entry.async_unload(hass)
+
+    assert entry.state == ConfigEntryState.NOT_LOADED
+
+
+async def test_async_setup_entry_new_tokens(hass: HomeAssistant) -> None:
+    """Test setting up entry and getting new tokens."""
+    entry = await async_init_integration(
+        hass, devices_fixture="get_devices_with_tokens.json"
+    )
+
+    assert entry.data == {
+        CONF_REGION: "europe",
+        CONF_USERNAME: "sample@gmail.com",
+        CONF_API_TOKEN: "new_api_token",
+        CONF_OWLET_EXPIRY: 200,
+        CONF_OWLET_REFRESH: "new_refresh_token",
+    }
+
+    assert entry.state == ConfigEntryState.LOADED
+
+    await entry.async_unload(hass)
+
+    assert entry.state == ConfigEntryState.NOT_LOADED
+
+
+async def test_async_setup_entry_auth_error(hass: HomeAssistant) -> None:
+    """Test setting up entry with auth error."""
+    entry = await async_init_integration(hass, skip_setup=True)
+
+    with patch(
+        "homeassistant.components.owlet.OwletAPI.authenticate",
+        side_effect=OwletAuthenticationError(),
+    ):
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+        assert entry.state == ConfigEntryState.SETUP_ERROR
+
+        await entry.async_unload(hass)
+
+
+async def test_async_setup_entry_connection_error(hass: HomeAssistant) -> None:
+    """Test setting up entry with connection error."""
+    entry = await async_init_integration(hass, skip_setup=True)
+
+    with patch(
+        "homeassistant.components.owlet.OwletAPI.authenticate",
+        side_effect=OwletConnectionError(),
+    ):
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+        assert entry.state == ConfigEntryState.SETUP_RETRY
+
+        await entry.async_unload(hass)
+
+
+async def test_async_setup_entry_devices_error(hass: HomeAssistant) -> None:
+    """Test setting up entry with device error."""
+    entry = await async_init_integration(hass, skip_setup=True)
+
+    with patch(
+        "homeassistant.components.owlet.OwletAPI.authenticate", return_value=None
+    ), patch(
+        "homeassistant.components.owlet.OwletAPI.get_devices",
+        side_effect=OwletDevicesError(),
+    ):
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+        assert entry.state == ConfigEntryState.SETUP_ERROR
+        await entry.async_unload(hass)
+
+
+async def test_async_setup_entry_error(hass: HomeAssistant) -> None:
+    """Test setting up entry with unknown error."""
+    entry = await async_init_integration(hass, skip_setup=True)
+
+    with patch(
+        "homeassistant.components.owlet.OwletAPI.authenticate",
+        side_effect=OwletError(),
+    ):
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+        assert entry.state == ConfigEntryState.SETUP_ERROR
+
+        await entry.async_unload(hass)