[sensor] Share filter_out and throttle_with_priority value tables in flash (#20078)

tests/component_tests/sensor/test_value_list.py

@@ -0,0 +1,43 @@
+"""Tests for the sensor value list filter codegen."""
+
+from collections.abc import Callable
+import re
+
+
+def test_value_list_filters_share_progmem_tables(
+    generate_main: Callable[[str], str],
+) -> None:
+    """Identical value lists share one PROGMEM table; the NaN throttle stays array free."""
+    main_cpp = generate_main("tests/component_tests/sensor/test_value_list.yaml")
+
+    tables = re.findall(
+        r"static constexpr TemplatableFn<float> (\w+)\[\] PROGMEM", main_cpp
+    )
+    # Every table ends with an empty entry so the filters store no count.
+    assert main_cpp.count("TemplatableFn<float>()}") == len(tables)
+    assert (
+        len(tables) == 5
+    )  # single, shared list, lambda, two anchored stateful lambdas
+    single, shared, lam = tables[:3]
+    assert f"sensor::FilterOutValueFilter({single});" in main_cpp
+    assert main_cpp.count(f"sensor::FilterOutValueFilter({shared});") == 2
+    assert f"sensor::FilterOutValueFilter({lam});" in main_cpp
+    assert f"sensor::ThrottleWithPriorityFilter(1000, {shared});" in main_cpp
+    assert "sensor::ThrottleWithPriorityNanFilter(1000);" in main_cpp
+    assert "return 42.0;" in main_cpp
+
+
+def test_value_list_lambda_tables_are_not_shared(
+    generate_main: Callable[[str], str],
+) -> None:
+    """An anchored lambda may keep static state, so each filter keeps its own table."""
+    main_cpp = generate_main("tests/component_tests/sensor/test_value_list.yaml")
+
+    tables = re.findall(
+        r"static constexpr TemplatableFn<float> (\w+)\[\] PROGMEM = (.*?)TemplatableFn<float>\(\)\}",
+        main_cpp,
+        re.DOTALL,
+    )
+    stateful = [name for name, body in tables if "static float n" in body]
+    assert len(stateful) == 2
+    assert stateful[0] != stateful[1]

tests/component_tests/sensor/test_value_list.yaml

@@ -0,0 +1,51 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+sensor:
+  - platform: template
+    id: fo_single
+    lambda: return 1.0;
+    filters:
+      - filter_out: 85.0
+  - platform: template
+    id: fo_list_a
+    lambda: return 1.0;
+    filters:
+      - filter_out: [0.0, 85.0]
+  - platform: template
+    id: fo_list_b
+    lambda: return 1.0;
+    filters:
+      - filter_out: [0.0, 85.0]
+  - platform: template
+    id: fo_lambda
+    lambda: return 1.0;
+    filters:
+      - filter_out: !lambda return 42.0;
+  - platform: template
+    id: twp
+    lambda: return 1.0;
+    filters:
+      - throttle_with_priority:
+          timeout: 1s
+          value: [0.0, 85.0]
+  - platform: template
+    id: twp_nan
+    lambda: return 1.0;
+    filters:
+      - throttle_with_priority: 1s
+  - platform: template
+    id: fo_stateful_a
+    lambda: return 1.0;
+    filters:
+      - filter_out: &stateful !lambda |-
+          static float n = 0;
+          return ++n;
+  - platform: template
+    id: fo_stateful_b
+    lambda: return 1.0;
+    filters:
+      - filter_out: *stateful