[core] Shrink Component from 12 to 8 bytes per instance (#15103)

tests/unit_tests/test_cpp_helpers.py

@@ -1,8 +1,10 @@
+import logging
 from unittest.mock import Mock
 
 import pytest
 
 from esphome import const, cpp_helpers as ch
+from esphome.cpp_helpers import ComponentSourcePool, register_component_source
 
 
 @pytest.mark.asyncio
@@ -23,7 +25,7 @@ async def test_register_component(monkeypatch):
     app_mock = Mock(register_component_=Mock(return_value=var))
     monkeypatch.setattr(ch, "App", app_mock)
 
-    core_mock = Mock(component_ids=["foo.bar"])
+    core_mock = Mock(component_ids=["foo.bar"], data={})
     monkeypatch.setattr(ch, "CORE", core_mock)
 
     add_mock = Mock()
@@ -59,7 +61,7 @@ async def test_register_component__with_setup_priority(monkeypatch):
     app_mock = Mock(register_component_=Mock(return_value=var))
     monkeypatch.setattr(ch, "App", app_mock)
 
-    core_mock = Mock(component_ids=["foo.bar"])
+    core_mock = Mock(component_ids=["foo.bar"], data={})
     monkeypatch.setattr(ch, "CORE", core_mock)
 
     add_mock = Mock()
@@ -78,3 +80,69 @@ async def test_register_component__with_setup_priority(monkeypatch):
     assert add_mock.call_count == 4
     app_mock.register_component_.assert_called_with(var)
     assert core_mock.component_ids == []
+
+
+def test_register_component_source_empty_name(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setattr(ch, "CORE", Mock(data={}))
+    assert register_component_source("") == 0
+
+
+def test_register_component_source_deduplicates(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(ch, "CORE", Mock(data={}))
+    idx1 = register_component_source("wifi")
+    idx2 = register_component_source("api")
+    idx3 = register_component_source("wifi")
+    assert idx1 == 1
+    assert idx2 == 2
+    assert idx3 == 1  # deduplicated
+
+
+def test_generate_source_table_code_empty() -> None:
+    from esphome.cpp_helpers import _generate_source_table_code
+
+    assert _generate_source_table_code("TBL", "lookup", {}) == ""
+
+
+def test_generate_source_table_code_non_empty() -> None:
+    from esphome.cpp_helpers import _generate_source_table_code
+
+    code = _generate_source_table_code("TBL", "lookup", {"wifi": 1, "api": 2})
+    assert "PROGMEM" in code
+    assert "wifi" in code
+    assert "api" in code
+    assert "lookup" in code
+    assert "index == 0" in code
+    assert "progmem_read_ptr" in code
+    assert "index > 2" in code
+
+
+@pytest.mark.asyncio
+async def test_generate_component_source_table_empty_pool(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Test that _generate_component_source_table does nothing with an empty pool."""
+    from esphome.cpp_helpers import _generate_component_source_table
+
+    monkeypatch.setattr(ch, "CORE", Mock(data={}))
+    add_global_mock = Mock()
+    monkeypatch.setattr(ch, "add_global", add_global_mock)
+    await _generate_component_source_table()
+    add_global_mock.assert_not_called()
+
+
+def test_register_component_source_overflow_warns(
+    monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    # Pre-fill pool to max
+    pool = ComponentSourcePool(
+        sources={f"comp_{i}": i + 1 for i in range(0xFF)},
+        table_registered=True,
+    )
+    monkeypatch.setattr(ch, "CORE", Mock(data={ch._COMPONENT_SOURCE_DOMAIN: pool}))
+    with caplog.at_level(logging.WARNING):
+        idx = register_component_source("overflow_component")
+    assert idx == 0
+    assert "Too many unique component source names" in caplog.text
+    assert "overflow_component" in caplog.text