[mitsubishi_cn105] Add Fahrenheit support (#15488)

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

tests/components/mitsubishi_cn105/climate/mitsubishi_cn105_climate_tests.cpp

@@ -1,7 +1,67 @@
+#include <array>
+#include <utility>
 #include "../common.h"
 
 namespace esphome::mitsubishi_cn105::testing {
 
+TEST(MitsubishiCN105ClimateTests, CelsiusTemperatureMappingAndTraitsMatchExpectedValues) {
+  TestableMitsubishiCN105Climate sut;
+  const auto mapping = TemperatureMapping();
+
+  for (int temperature = 16; temperature <= 31; ++temperature) {
+    EXPECT_EQ(mapping.to_mitsubishi(temperature), temperature);
+    EXPECT_EQ(mapping.from_mitsubishi(temperature), temperature);
+  }
+
+  const auto traits = sut.traits();
+  EXPECT_EQ(traits.get_temperature_unit(), TemperatureUnit::CELSIUS);
+  EXPECT_FLOAT_EQ(traits.get_visual_min_temperature(), 16.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_max_temperature(), 31.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_target_temperature_step(), 1.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_current_temperature_step(), 0.5f);
+}
+
+TEST(MitsubishiCN105ClimateTests, FahrenheitTemperatureMappingAndTraitsMatchExpectedValues) {
+  TestableMitsubishiCN105Climate sut;
+  auto mapping = TemperatureMapping();
+  mapping.set_use_fahrenheit(true);
+  sut.set_use_fahrenheit(true);
+
+  const std::array cases{
+      std::pair{61, 16.0f}, std::pair{62, 16.5f}, std::pair{63, 17.0f}, std::pair{64, 17.5f}, std::pair{65, 18.0f},
+      std::pair{66, 18.5f}, std::pair{67, 19.0f}, std::pair{68, 20.0f}, std::pair{69, 21.0f}, std::pair{70, 21.5f},
+      std::pair{71, 22.0f}, std::pair{72, 22.5f}, std::pair{73, 23.0f}, std::pair{74, 23.5f}, std::pair{75, 24.0f},
+      std::pair{76, 24.5f}, std::pair{77, 25.0f}, std::pair{78, 25.5f}, std::pair{79, 26.0f}, std::pair{80, 26.5f},
+      std::pair{81, 27.0f}, std::pair{82, 27.5f}, std::pair{83, 28.0f}, std::pair{84, 28.5f}, std::pair{85, 29.0f},
+      std::pair{86, 29.5f}, std::pair{87, 30.0f}, std::pair{88, 30.5f},
+  };
+
+  for (const auto &[fahrenheit, mitsubishi_celsius] : cases) {
+    EXPECT_FLOAT_EQ(mapping.to_mitsubishi(fahrenheit), mitsubishi_celsius);
+    EXPECT_FLOAT_EQ(mapping.from_mitsubishi(mitsubishi_celsius), fahrenheit);
+  }
+  const auto traits = sut.traits();
+  EXPECT_EQ(traits.get_temperature_unit(), TemperatureUnit::FAHRENHEIT);
+  EXPECT_FLOAT_EQ(traits.get_visual_min_temperature(), 61.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_max_temperature(), 88.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_target_temperature_step(), 1.0f);
+  EXPECT_FLOAT_EQ(traits.get_visual_current_temperature_step(), 1.0f);
+}
+
+TEST(MitsubishiCN105ClimateTests, FahrenheitTemperatureMappingUsesLinearConversionOutsideSetpointRange) {
+  auto mapping = TemperatureMapping();
+  mapping.set_use_fahrenheit(true);
+
+  const std::array cases{
+      std::pair{0.0f, 32.0f},  std::pair{10.0f, 50.0f}, std::pair{15.5f, 59.9f},
+      std::pair{31.0f, 87.8f}, std::pair{35.0f, 95.0f}, std::pair{40.0f, 104.0f},
+  };
+
+  for (const auto &[celsius, fahrenheit] : cases) {
+    EXPECT_FLOAT_EQ(mapping.from_mitsubishi(celsius), fahrenheit);
+  }
+}
+
 TEST(MitsubishiCN105ClimateTests, SupportedSwingModeOffLeavesTraitsEmpty) {
   TestableMitsubishiCN105Climate sut;
 

tests/components/mitsubishi_cn105/common.h

@@ -73,6 +73,7 @@ class TestableMitsubishiCN105Climate : public MitsubishiCN105Climate {
   using MitsubishiCN105Climate::last_non_swing_wide_vane_mode_;
 
   MitsubishiCN105::Status &status() { return const_cast<MitsubishiCN105::Status &>(this->component_.status()); }
+  void set_use_fahrenheit(bool value) { this->component_.set_use_fahrenheit(value); }
 
  protected:
   MitsubishiCN105Component component_;

tests/components/mitsubishi_cn105/common.yaml

@@ -3,6 +3,7 @@ mitsubishi_cn105:
   uart_id: uart_bus
   update_interval: 30s
   telemetry_request_min_interval: 120s
+  use_fahrenheit: true
   vane:
     on_state:
       - logger.log: