[exponential_moving_average] Add EMA preserved across reboots (#19882)

Co-authored-by: J. Nick Koston <nick@koston.org>

tests/component_tests/exponential_moving_average/config/exponential_moving_average_test.yaml

@@ -0,0 +1,40 @@
+esphome:
+  name: test
+  on_boot:
+    then:
+      - sensor.exponential_moving_average.reset: ema_default
+
+esp32:
+  board: esp32dev
+
+sensor:
+  - platform: template
+    id: source_sensor
+    unit_of_measurement: "°C"
+    accuracy_decimals: 1
+    device_class: temperature
+    state_class: measurement
+    lambda: return 1.0;
+  - platform: exponential_moving_average
+    id: ema_default
+    name: EMA Default
+    sensor: source_sensor
+  - platform: exponential_moving_average
+    id: ema_alpha
+    name: EMA Alpha
+    sensor: source_sensor
+    alpha: 0.25
+    unit_of_measurement: "K"
+    accuracy_decimals: 3
+  - platform: exponential_moving_average
+    id: ema_time_constant
+    name: EMA Time Constant
+    sensor: source_sensor
+    time_constant: 5min
+    restore: false
+  - platform: exponential_moving_average
+    id: ema_linear
+    name: EMA Linear
+    sensor: source_sensor
+    time_constant: 30s
+    time_weighting: linear

tests/component_tests/exponential_moving_average/test_exponential_moving_average.py

@@ -0,0 +1,166 @@
+"""Tests for the exponential_moving_average sensor."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+from esphome import config_validation as cv
+from esphome.components.exponential_moving_average.sensor import CONFIG_SCHEMA
+
+
+def test_default_alpha_and_restore(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Without alpha or time_constant, alpha defaults to 0.1 and restore is on."""
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert (
+        "new(ema_default) exponential_moving_average::ExponentialMovingAverageSensor(source_sensor);"
+        in main_cpp
+    )
+    assert "ema_default->set_alpha(0.1f);" in main_cpp
+    assert "ema_default->set_restore(true);" in main_cpp
+
+
+def test_alpha(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert "ema_alpha->set_alpha(0.25f);" in main_cpp
+    assert "ema_alpha->set_time_constant" not in main_cpp
+
+
+def test_time_constant_replaces_alpha(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert "ema_time_constant->set_time_constant(300000);" in main_cpp
+    assert "ema_time_constant->set_alpha" not in main_cpp
+    assert "ema_time_constant->set_restore(false);" in main_cpp
+    assert "ema_time_constant->set_time_weighting" not in main_cpp
+
+
+def test_time_weighting(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert "ema_linear->set_time_constant(30000);" in main_cpp
+    assert (
+        "ema_linear->set_time_weighting(exponential_moving_average::TIME_WEIGHTING_LINEAR);"
+        in main_cpp
+    )
+
+
+def test_properties_inherited_from_source(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Unset properties come from the source sensor, with one extra decimal; set ones are kept."""
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert "ema_default->set_accuracy_decimals(2);" in main_cpp
+    assert "ema_alpha->set_accuracy_decimals(3);" in main_cpp
+    default_line = next(
+        line for line in main_cpp.splitlines() if '"EMA Default"' in line
+    )
+    alpha_line = next(line for line in main_cpp.splitlines() if '"EMA Alpha"' in line)
+    assert "°C" in default_line
+    assert "temperature" in default_line
+    assert "K" in alpha_line
+
+
+def test_reset_action(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(
+        component_config_path("exponential_moving_average_test.yaml")
+    )
+
+    assert "::ema_default->reset();" in main_cpp
+
+
+def test_alpha_and_time_constant_are_exclusive() -> None:
+    with pytest.raises(cv.Invalid, match="Cannot specify more than one of"):
+        CONFIG_SCHEMA(
+            {
+                "id": "ema",
+                "name": "EMA",
+                "sensor": "source",
+                "alpha": 0.5,
+                "time_constant": "1min",
+            }
+        )
+
+
+@pytest.mark.parametrize("alpha", [0, -0.1, 1.5])
+def test_alpha_out_of_range(alpha: float) -> None:
+    with pytest.raises(cv.Invalid):
+        CONFIG_SCHEMA({"id": "ema", "name": "EMA", "sensor": "source", "alpha": alpha})
+
+
+@pytest.mark.parametrize("alpha", [0.01, 1])
+def test_alpha_in_range(alpha: float) -> None:
+    config = CONFIG_SCHEMA(
+        {"id": "ema", "name": "EMA", "sensor": "source", "alpha": alpha}
+    )
+
+    assert config["alpha"] == alpha
+
+
+def test_time_weighting_requires_time_constant() -> None:
+    with pytest.raises(cv.Invalid, match="can only be used with 'time_constant'"):
+        CONFIG_SCHEMA(
+            {
+                "id": "ema",
+                "name": "EMA",
+                "sensor": "source",
+                "time_weighting": "previous",
+            }
+        )
+
+
+@pytest.mark.parametrize("weighting", ["new", "previous", "linear", "LINEAR"])
+def test_time_weighting_values(weighting: str) -> None:
+    config = CONFIG_SCHEMA(
+        {
+            "id": "ema",
+            "name": "EMA",
+            "sensor": "source",
+            "time_constant": "1min",
+            "time_weighting": weighting,
+        }
+    )
+
+    assert config["time_weighting"] == weighting.lower()
+
+
+def test_time_weighting_rejects_unknown_value() -> None:
+    with pytest.raises(cv.Invalid):
+        CONFIG_SCHEMA(
+            {
+                "id": "ema",
+                "name": "EMA",
+                "sensor": "source",
+                "time_constant": "1min",
+                "time_weighting": "trapezoid",
+            }
+        )