[hoermann_hcp] Add connectivity binary sensor (#18189)

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

tests/components/hoermann_hcp/binary_sensor/hoermann_hcp_binary_sensor_test.cpp

@@ -0,0 +1,72 @@
+#include <gtest/gtest.h>
+
+#include "esphome/components/hoermann_hcp/binary_sensor/hoermann_hcp_binary_sensor.h"
+
+namespace esphome::hoermann_hcp {
+
+using modbus::RegisterValues;
+
+namespace {
+
+constexpr uint16_t COMMAND_REG = 0x9C41;
+constexpr uint16_t BROADCAST_REG = 0x9D31;
+
+RegisterValues make_registers(std::initializer_list<uint16_t> values) {
+  RegisterValues registers;
+  for (uint16_t value : values)
+    registers.push_back(value);
+  return registers;
+}
+
+// Exposes the connection bookkeeping so a drop can be driven without waiting one out.
+class TestableHoermannHcp : public HoermannHcp {
+ public:
+  using HoermannHcp::set_valid_;
+};
+
+}  // namespace
+
+// Nothing has been heard from the bus controller yet, so the sensor starts out seeded as disconnected.
+TEST(HoermannHcpBinarySensorTest, StartsDisconnected) {
+  HoermannHcp door;
+  HoermannHcpConnectedBinarySensor sensor(&door);
+  sensor.setup();
+  EXPECT_TRUE(sensor.has_state());
+  EXPECT_FALSE(sensor.state);
+}
+
+// The connection flag follows the bus controller in both directions.
+TEST(HoermannHcpBinarySensorTest, FollowsTheConnectionState) {
+  TestableHoermannHcp door;
+  HoermannHcpConnectedBinarySensor sensor(&door);
+  sensor.setup();
+  ASSERT_FALSE(sensor.state);
+
+  door.on_write_registers(COMMAND_REG, make_registers({0x0000, 0x0000}));
+  door.update();
+  EXPECT_TRUE(sensor.state);
+
+  door.set_valid_(false);
+  door.update();
+  EXPECT_FALSE(sensor.state);
+}
+
+// Any hub change re-runs the publish path, so an unchanged connection must not be reported twice.
+TEST(HoermannHcpBinarySensorTest, UnchangedConnectionIsPublishedOnce) {
+  HoermannHcp door;
+  HoermannHcpConnectedBinarySensor sensor(&door);
+  sensor.setup();
+  int publishes = 0;
+  sensor.add_on_state_callback([&publishes](bool /*state*/) { publishes++; });
+
+  door.on_write_registers(COMMAND_REG, make_registers({0x0000, 0x0000}));
+  door.update();
+  ASSERT_EQ(publishes, 1);
+
+  // A status broadcast changes the door state without touching the connection.
+  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0064, 0x0100}));
+  door.update();
+  EXPECT_EQ(publishes, 1);
+}
+
+}  // namespace esphome::hoermann_hcp

tests/components/hoermann_hcp/common.yaml

@@ -6,3 +6,8 @@ cover:
   - platform: hoermann_hcp
     name: Garage Door
     device_class: garage
+
+binary_sensor:
+  - platform: hoermann_hcp
+    is_connected:
+      name: Garage Connected