[api] Skip setters that pass the default port, reboot timeout and batch delay (#19227)

tests/component_tests/api/config/bare.yaml

@@ -0,0 +1,12 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:

tests/component_tests/api/config/custom.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:
+  port: 6054
+  reboot_timeout: 0s
+  batch_delay: 0ms

tests/component_tests/api/config/defaults.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:
+  port: 6053
+  reboot_timeout: 15min
+  batch_delay: 100ms

tests/component_tests/api/test_default_setters.py

@@ -0,0 +1,35 @@
+"""Tests that the api component only emits setters for non default values."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.parametrize("config_file", ["bare.yaml", "defaults.yaml"])
+def test_default_values_are_not_emitted(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+    config_file: str,
+) -> None:
+    """Port 6053, a 15 min reboot timeout and 100 ms batch delay are C++ initializers.
+
+    Both the schema defaults and the same values written explicitly take the skip path.
+    """
+    main_cpp = generate_main(component_config_path(config_file))
+
+    assert "api_apiserver_id->set_port(" not in main_cpp
+    assert "api_apiserver_id->set_reboot_timeout(" not in main_cpp
+    assert "api_apiserver_id->set_batch_delay(" not in main_cpp
+
+
+def test_custom_values_are_emitted(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Non default values still reach the C++ setters."""
+    main_cpp = generate_main(component_config_path("custom.yaml"))
+
+    assert "api_apiserver_id->set_port(6054);" in main_cpp
+    assert "api_apiserver_id->set_reboot_timeout(0);" in main_cpp
+    assert "api_apiserver_id->set_batch_delay(0);" in main_cpp