[fan] fix initial FanCall to properly set speed (#8277)

tests/integration/fixtures/host_mode_fan_preset.yaml

@@ -0,0 +1,34 @@
+esphome:
+  name: host-test
+
+host:
+
+api:
+
+logger:
+
+# Test fan with preset modes and speed settings
+fan:
+  - platform: template
+    name: "Test Fan with Presets"
+    id: test_fan_presets
+    speed_count: 5
+    preset_modes:
+      - "Eco"
+      - "Sleep"
+      - "Turbo"
+    has_oscillating: true
+    has_direction: true
+
+  - platform: template
+    name: "Test Fan Simple"
+    id: test_fan_simple
+    speed_count: 3
+    has_oscillating: false
+    has_direction: false
+
+  - platform: template
+    name: "Test Fan No Speed"
+    id: test_fan_no_speed
+    has_oscillating: true
+    has_direction: false

tests/integration/test_host_mode_fan_preset.py

@@ -0,0 +1,152 @@
+"""Integration test for fan preset mode behavior."""
+
+from __future__ import annotations
+
+import asyncio
+
+from aioesphomeapi import FanInfo, FanState
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_host_mode_fan_preset(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test fan preset mode behavior according to Home Assistant guidelines."""
+    # Write, compile and run the ESPHome device, then connect to API
+    async with run_compiled(yaml_config), api_client_connected() as client:
+        # Get all fan entities
+        entities = await client.list_entities_services()
+        fans: list[FanInfo] = []
+        for entity_list in entities:
+            for entity in entity_list:
+                if isinstance(entity, FanInfo):
+                    fans.append(entity)
+
+        # Create a map of fan names to entity info
+        fan_map = {fan.name: fan for fan in fans}
+
+        # Verify we have our test fans
+        assert "Test Fan with Presets" in fan_map
+        assert "Test Fan Simple" in fan_map
+        assert "Test Fan No Speed" in fan_map
+
+        # Get fan with presets
+        fan_presets = fan_map["Test Fan with Presets"]
+        assert fan_presets.supports_speed is True
+        assert fan_presets.supported_speed_count == 5
+        assert fan_presets.supports_oscillation is True
+        assert fan_presets.supports_direction is True
+        assert set(fan_presets.supported_preset_modes) == {"Eco", "Sleep", "Turbo"}
+
+        # Subscribe to states
+        states: dict[int, FanState] = {}
+        state_event = asyncio.Event()
+
+        def on_state(state: FanState) -> None:
+            if isinstance(state, FanState):
+                states[state.key] = state
+                state_event.set()
+
+        client.subscribe_states(on_state)
+
+        # Test 1: Turn on fan without speed or preset - should set speed to 100%
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            state=True,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_presets.key]
+        assert fan_state.state is True
+        assert fan_state.speed_level == 5  # Should be max speed (100%)
+        assert fan_state.preset_mode == ""
+
+        # Turn off
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            state=False,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        # Test 2: Turn on fan with preset mode - should NOT set speed to 100%
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            state=True,
+            preset_mode="Eco",
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_presets.key]
+        assert fan_state.state is True
+        assert fan_state.preset_mode == "Eco"
+        # Speed should be whatever the preset sets, not forced to 100%
+
+        # Test 3: Setting speed should clear preset mode
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            speed_level=3,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_presets.key]
+        assert fan_state.state is True
+        assert fan_state.speed_level == 3
+        assert fan_state.preset_mode == ""  # Preset mode should be cleared
+
+        # Test 4: Setting preset mode should work when fan is already on
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            preset_mode="Sleep",
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_presets.key]
+        assert fan_state.state is True
+        assert fan_state.preset_mode == "Sleep"
+
+        # Turn off
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            state=False,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        # Test 5: Turn on fan with specific speed
+        state_event.clear()
+        client.fan_command(
+            key=fan_presets.key,
+            state=True,
+            speed_level=2,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_presets.key]
+        assert fan_state.state is True
+        assert fan_state.speed_level == 2
+        assert fan_state.preset_mode == ""
+
+        # Test 6: Test fan with no speed support
+        fan_no_speed = fan_map["Test Fan No Speed"]
+        assert fan_no_speed.supports_speed is False
+
+        state_event.clear()
+        client.fan_command(
+            key=fan_no_speed.key,
+            state=True,
+        )
+        await asyncio.wait_for(state_event.wait(), timeout=2.0)
+
+        fan_state = states[fan_no_speed.key]
+        assert fan_state.state is True
+        # No speed should be set for fans that don't support speed