[libretiny] Give each platform its own CONFIG_SCHEMA instance (#18056)

esphome/components/bk72xx/__init__.py

@@ -51,7 +51,11 @@ def _set_core_data(config):
     return config
 
 
-CONFIG_SCHEMA = libretiny.BASE_SCHEMA
+# extend({}) makes this platform's own schema instance: BASE_SCHEMA is shared
+# by every LibreTiny platform, and prepending this platform's _set_core_data
+# onto the shared object would run it for every platform's validation once two
+# platform modules are imported in one process (device-builder, tests).
+CONFIG_SCHEMA = libretiny.BASE_SCHEMA.extend({})
 
 PIN_SCHEMA = libretiny.gpio.BASE_PIN_SCHEMA
 

esphome/components/libretiny/generate_components.py

@@ -65,6 +65,10 @@ def _set_core_data(config):
     return config
 
 
+# extend({}) makes this platform's own schema instance: BASE_SCHEMA is shared
+# by every LibreTiny platform, and prepending this platform's _set_core_data
+# onto the shared object would run it for every platform's validation once two
+# platform modules are imported in one process (device-builder, tests).
 CONFIG_SCHEMA = {SCHEMA}
 
 PIN_SCHEMA = {PIN_SCHEMA}
@@ -117,7 +121,7 @@ VAR_GPIO_PIN = "validate_pin"
 VAR_GPIO_USAGE = "validate_usage"
 
 # lines for code snippets
-SCHEMA_BASE = "libretiny.BASE_SCHEMA"
+SCHEMA_BASE = "libretiny.BASE_SCHEMA.extend({})"
 SCHEMA_EXTRA = f"libretiny.BASE_SCHEMA.extend({VAR_SCHEMA})"
 PIN_SCHEMA_BASE = "libretiny.gpio.BASE_PIN_SCHEMA"
 PIN_SCHEMA_EXTRA = f"libretiny.BASE_PIN_SCHEMA.extend({VAR_PIN_SCHEMA})"

esphome/components/ln882x/__init__.py

@@ -51,7 +51,11 @@ def _set_core_data(config):
     return config
 
 
-CONFIG_SCHEMA = libretiny.BASE_SCHEMA
+# extend({}) makes this platform's own schema instance: BASE_SCHEMA is shared
+# by every LibreTiny platform, and prepending this platform's _set_core_data
+# onto the shared object would run it for every platform's validation once two
+# platform modules are imported in one process (device-builder, tests).
+CONFIG_SCHEMA = libretiny.BASE_SCHEMA.extend({})
 
 PIN_SCHEMA = libretiny.gpio.BASE_PIN_SCHEMA
 

esphome/components/rtl87xx/__init__.py

@@ -51,7 +51,11 @@ def _set_core_data(config):
     return config
 
 
-CONFIG_SCHEMA = libretiny.BASE_SCHEMA
+# extend({}) makes this platform's own schema instance: BASE_SCHEMA is shared
+# by every LibreTiny platform, and prepending this platform's _set_core_data
+# onto the shared object would run it for every platform's validation once two
+# platform modules are imported in one process (device-builder, tests).
+CONFIG_SCHEMA = libretiny.BASE_SCHEMA.extend({})
 
 PIN_SCHEMA = libretiny.gpio.BASE_PIN_SCHEMA
 

tests/unit_tests/components/test_libretiny.py

@@ -2,7 +2,8 @@
 
 import pytest
 
-from esphome.components.libretiny import _detect_variant
+from esphome.components import bk72xx, ln882x, rtl87xx
+from esphome.components.libretiny import BASE_SCHEMA, _detect_variant
 from esphome.components.libretiny.const import (
     FAMILY_LN882H,
     KEY_COMPONENT_DATA,
@@ -11,7 +12,7 @@ from esphome.components.libretiny.const import (
 from esphome.components.ln882x import COMPONENT_DATA
 import esphome.config_validation as cv
 from esphome.const import CONF_BOARD, CONF_FAMILY
-from esphome.core import CORE
+from esphome.core import CORE, KEY_CORE
 
 
 @pytest.fixture
@@ -50,3 +51,36 @@ def test_detect_variant_unknown_board_still_raises(ln882x_core_data: None) -> No
     """Ids outside the rename map keep the family-override error."""
     with pytest.raises(cv.Invalid, match="This board is unknown"):
         _detect_variant({CONF_BOARD: "not-a-real-board"})
+
+
+def test_platform_schemas_are_isolated_instances() -> None:
+    """Each LibreTiny platform must own its CONFIG_SCHEMA instance.
+
+    BASE_SCHEMA is shared; every platform prepends its own _set_core_data
+    extra. On the shared object, importing two platform modules in one process
+    made either platform's validation run both extras, so the wrong platform's
+    component data won and known boards failed to resolve.
+    """
+    platforms = (bk72xx, ln882x, rtl87xx)
+    schemas = [platform.CONFIG_SCHEMA for platform in platforms]
+    assert len({id(schema) for schema in (BASE_SCHEMA, *schemas)}) == 4
+    # The shared base must not have accumulated any platform's extra.
+    # prepend_extra wraps validators in _Schema, so unwrap before comparing.
+    base_extras = [extra.schema for extra in BASE_SCHEMA._extra_schemas]
+    for platform in platforms:
+        assert platform._set_core_data not in base_extras
+
+
+def test_each_platform_resolves_its_own_boards() -> None:
+    """Validating one platform's config must leave that platform's component
+    data in CORE.data. On the shared schema, the last-imported platform's
+    _set_core_data won for every platform, so known boards failed to resolve
+    with "This board is unknown"."""
+    CORE.data[KEY_CORE] = {}  # written by the schema's _update_core_data extra
+    for platform, board in (
+        (ln882x, "generic-ln882h"),
+        (bk72xx, "generic-bk7252"),
+        (rtl87xx, "generic-rtl8720cf-2mb-896k"),
+    ):
+        platform.CONFIG_SCHEMA({CONF_BOARD: board})
+        assert CORE.data[KEY_LIBRETINY][KEY_COMPONENT_DATA] is platform.COMPONENT_DATA