Add date platform (#81948)

tests/testing_config/custom_components/test/date.py

@@ -0,0 +1,50 @@
+"""Provide a mock date platform.
+
+Call init before using it in your tests to ensure clean test data.
+"""
+from datetime import date
+
+from homeassistant.components.date import DateEntity
+
+from tests.common import MockEntity
+
+UNIQUE_DATE = "unique_date"
+
+ENTITIES = []
+
+
+class MockDateEntity(MockEntity, DateEntity):
+    """Mock date class."""
+
+    @property
+    def native_value(self):
+        """Return the native value of this date."""
+        return self._handle("native_value")
+
+    def set_value(self, value: date) -> None:
+        """Change the date."""
+        self._values["native_value"] = value
+
+
+def init(empty=False):
+    """Initialize the platform with entities."""
+    global ENTITIES
+
+    ENTITIES = (
+        []
+        if empty
+        else [
+            MockDateEntity(
+                name="test",
+                unique_id=UNIQUE_DATE,
+                native_value=date(2020, 1, 1),
+            ),
+        ]
+    )
+
+
+async def async_setup_platform(
+    hass, config, async_add_entities_callback, discovery_info=None
+):
+    """Return mock entities."""
+    async_add_entities_callback(ENTITIES)