Add Button entity component platform (#57642)

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>
Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

tests/testing_config/custom_components/test/button.py

@@ -0,0 +1,47 @@
+"""
+Provide a mock button platform.
+
+Call init before using it in your tests to ensure clean test data.
+"""
+import logging
+
+from homeassistant.components.button import ButtonEntity
+
+from tests.common import MockEntity
+
+UNIQUE_BUTTON_1 = "unique_button_1"
+
+ENTITIES = []
+
+_LOGGER = logging.getLogger(__name__)
+
+
+class MockButtonEntity(MockEntity, ButtonEntity):
+    """Mock Button class."""
+
+    def press(self) -> None:
+        """Press the button."""
+        _LOGGER.info("The button has been pressed")
+
+
+def init(empty=False):
+    """Initialize the platform with entities."""
+    global ENTITIES
+
+    ENTITIES = (
+        []
+        if empty
+        else [
+            MockButtonEntity(
+                name="button 1",
+                unique_id="unique_button_1",
+            ),
+        ]
+    )
+
+
+async def async_setup_platform(
+    hass, config, async_add_entities_callback, discovery_info=None
+):
+    """Return mock entities."""
+    async_add_entities_callback(ENTITIES)