[remote_base] Accept protocols registered by external components (#19332)

tests/component_tests/remote_receiver/external_components/fake_protocol/__init__.py

@@ -0,0 +1,39 @@
+"""External component registering a protocol that has no source file in remote_base."""
+
+import esphome.codegen as cg
+from esphome.components import remote_base
+import esphome.config_validation as cv
+from esphome.types import ConfigType
+
+DEPENDENCIES = ["remote_base"]
+
+ns = cg.esphome_ns.namespace("fake_protocol")
+FakeData = ns.struct("FakeData")
+FakeBinarySensor = ns.class_(
+    "FakeBinarySensor", remote_base.RemoteReceiverBinarySensorBase
+)
+FakeTrigger = ns.class_("FakeTrigger", remote_base.RemoteReceiverTrigger)
+FakeAction = ns.class_("FakeAction", remote_base.RemoteTransmitterActionBase)
+FakeDumper = ns.class_("FakeDumper", remote_base.RemoteReceiverDumperBase)
+
+CONFIG_SCHEMA = cv.Schema({})
+
+
+@remote_base.register_binary_sensor("fake", FakeBinarySensor, {})
+def fake_binary_sensor(var: cg.MockObj, config: ConfigType) -> None:
+    pass
+
+
+@remote_base.register_trigger("fake", FakeTrigger, FakeData)
+def fake_trigger(var: cg.MockObj, config: ConfigType) -> None:
+    pass
+
+
+@remote_base.register_dumper("fake", FakeDumper)
+def fake_dumper(var: cg.MockObj, config: ConfigType) -> None:
+    pass
+
+
+@remote_base.register_action("fake", FakeAction, {})
+async def fake_action(var: cg.MockObj, config: ConfigType, args: list) -> None:
+    pass