[esp8266] Use our own Arduino core builds for the native toolchain (#19876)

tests/unit_tests/components/esp8266/test_framework_version.py

@@ -2,9 +2,14 @@
 
 import pytest
 
-from esphome.components.esp8266 import _arduino_check_versions
+from esphome.components.esp8266 import (
+    _arduino_check_versions,
+    _format_framework_arduino_version,
+    _framework_package_version,
+)
 import esphome.config_validation as cv
 from esphome.const import CONF_PLATFORM_VERSION, CONF_VERSION
+from esphome.core import EsphomeError
 
 
 def test_versions_before_3_are_rejected() -> None:
@@ -21,3 +26,27 @@ def test_supported_versions_pass() -> None:
     value = _arduino_check_versions({CONF_VERSION: "recommended"})
     assert value[CONF_VERSION] == "3.1.2"
     assert "espressif8266@4.2.1" in value[CONF_PLATFORM_VERSION]
+
+
+def test_framework_package_version() -> None:
+    assert _framework_package_version(cv.Version(3, 1, 2)) == "3.30102.0"
+    assert _framework_package_version(cv.Version(3, 2, 0)) == "3.30200.0"
+    # A future major bump needs its own encoding, not a doomed registry lookup
+    with pytest.raises(EsphomeError, match="not supported yet"):
+        _framework_package_version(cv.Version(4, 0, 0))
+    # Cores before 3.x cannot build ESPHome (C++20) and are rejected
+    with pytest.raises(EsphomeError, match="requires core 3"):
+        _framework_package_version(cv.Version(2, 7, 4))
+
+
+def test_format_framework_arduino_version_pins_all_series() -> None:
+    """The PlatformIO source formatter across every encoding era."""
+
+    assert _format_framework_arduino_version(cv.Version(3, 1, 2)) == "~3.30102.0"
+    # Pre-3 cores are rejected with the version line anchored
+    with pytest.raises(cv.Invalid, match="requires core 3"):
+        _format_framework_arduino_version(cv.Version(2, 7, 4))
+    # Anchored to the framework version line, not a bare EsphomeError
+    with pytest.raises(cv.Invalid, match="not supported yet") as excinfo:
+        _format_framework_arduino_version(cv.Version(4, 0, 0))
+    assert excinfo.value.path == ["version"]

tests/unit_tests/components/esp8266/test_toolchain_validation.py

@@ -67,21 +67,24 @@ def test_valid_config_passes() -> None:
 
 
 def test_platformio_toolchain_skips_checks() -> None:
-    # 3.0.2 is pio-legal (>= the global 3.0.0 floor) but below the native
-    # toolchain's own 3.1.1 floor; the bogus board only the native path checks
+    # 3.0.2 is pio-legal (>= the global 3.0.0 floor) but has no native build;
+    # the bogus board only the native path checks
     CORE.toolchain = Toolchain.PLATFORMIO
     config = _config(board="not_a_board", version="3.0.2")
     assert _validate_native_toolchain(config) is config
 
 
-def test_version_below_floor_rejected() -> None:
-    # 3.1.0 has no registry package, so the native floor is 3.1.1
-    with pytest.raises(cv.Invalid, match="3.1.1 or newer"):
-        _validate_native_toolchain(_config(version="3.1.0"))
+def test_version_without_build_rejected() -> None:
+    """Only the core versions built in esphome-libs/arduino-esp8266 work."""
+    with pytest.raises(
+        cv.Invalid, match=r"3\.1\.1.*available: 3\.1\.2.*platformio"
+    ) as excinfo:
+        _validate_native_toolchain(_config(version="3.1.1"))
+    assert excinfo.value.path == [CONF_FRAMEWORK, CONF_VERSION]
 
 
-def test_version_at_floor_accepted() -> None:
-    _validate_native_toolchain(_config(version="3.1.1"))
+def test_built_version_accepted() -> None:
+    _validate_native_toolchain(_config(version="3.1.2"))
 
 
 def test_custom_platform_version_warns_and_is_dropped(