Pin the size command format in the template test, warn on schema drift

esphome/espidf/size_summary.py

@@ -130,7 +130,9 @@ def print_summary(size_json: Path, partitions_csv: Path, firmware_elf: Path) ->
     if ram_total and ram_used is not None:
         print_size_line("RAM", ram_used, ram_total)
     else:
-        _LOGGER.debug("Skipping RAM summary: no DRAM/DIRAM region in %s", size_json)
+        # Every chip has a DRAM or DIRAM region, so this firing usually
+        # means the esp_idf_size json schema changed
+        _LOGGER.warning("Skipping RAM summary: no DRAM/DIRAM region in %s", size_json)
 
     # esp-idf-size >= 2.1 (IDF >= 6.0) reports the exact image size in
     # json2; older 1.x omits it, so derive the same figure from the ELF.

tests/unit_tests/build_gen/test_espidf.py

@@ -163,6 +163,18 @@ def test_has_discovered_components_after_configure(tmp_path: Path) -> None:
     assert has_discovered_components()
 
 
+def test_get_project_cmakelists_size_command_uses_json2() -> None:
+    """The POST_BUILD size command uses the cheap json2 format, with --ng
+    only on the 1.x tool bundled with IDF < 6."""
+    content = _render()
+    assert "-m esp_idf_size --ng --format=json2" in content
+
+    CORE.data[KEY_ESP32][KEY_IDF_VERSION] = cv.Version(6, 0, 0)
+    content = _render()
+    assert "--ng" not in content
+    assert "--format=json2" in content
+
+
 def test_get_project_cmakelists_uses_supplied_builtin_components() -> None:
     """A cached list replaces project_description.json and is still filtered
     by EXCLUDE_COMPONENTS."""