[aqi] Add extended_range option for over-range AQI values (#17570)

Co-authored-by: jas <jas@asspa.in>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/component_tests/aqi/test_aqi.py

@@ -0,0 +1,35 @@
+"""Config-validation tests for the aqi sensor component."""
+
+import pytest
+from voluptuous import Invalid
+
+from esphome.components.aqi import CONF_CALCULATION_TYPE, CONF_EXTENDED_RANGE
+from esphome.components.aqi.sensor import _validate_extended_range
+
+
+def test_extended_range_rejected_with_caqi():
+    """extended_range has no meaning for CAQI (no spec maximum) and must be rejected."""
+    with pytest.raises(Invalid, match="CAQI"):
+        _validate_extended_range(
+            {CONF_CALCULATION_TYPE: "CAQI", CONF_EXTENDED_RANGE: True}
+        )
+
+
+def test_extended_range_rejected_with_caqi_even_when_false():
+    """The option is not allowed at all with CAQI, regardless of its value."""
+    with pytest.raises(Invalid, match="CAQI"):
+        _validate_extended_range(
+            {CONF_CALCULATION_TYPE: "CAQI", CONF_EXTENDED_RANGE: False}
+        )
+
+
+def test_extended_range_allowed_with_aqi():
+    """extended_range is valid for the US AQI calculation."""
+    config = {CONF_CALCULATION_TYPE: "AQI", CONF_EXTENDED_RANGE: True}
+    assert _validate_extended_range(config) is config
+
+
+def test_caqi_without_extended_range_ok():
+    """CAQI is fine as long as extended_range is not set."""
+    config = {CONF_CALCULATION_TYPE: "CAQI"}
+    assert _validate_extended_range(config) is config