fix(rf): FXC-3877 more robust suppression of RF license warning

CHANGELOG.md

@@ -61,6 +61,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - More accurate frequency range for ``GaussianPulse`` when DC is removed.
 - Bug in `TerminalComponentModelerData.get_antenna_metrics_data()` where `WavePort` mode indices were not properly handled. Improved docstrings and type hints to make the usage clearer.
 - Improved type hints for `Tidy3dBaseModel`, so that all derived classes will have more accurate return types.
+- More robust method for suppressing RF license warnings during tests.
 
 ## [v2.10.0rc2] - 2025-10-01
 

pyproject.toml

@@ -300,7 +300,7 @@ addopts = "--cov=tidy3d --doctest-modules -n auto --dist worksteal --assert=plai
 markers = [
   "numerical: marks numerical tests for adjoint gradients that require running simulations (deselect with '-m \"not numerical\"')",
 ]
-env = ["MPLBACKEND=Agg", "OMP_NUM_THREADS=1"]
+env = ["MPLBACKEND=Agg", "OMP_NUM_THREADS=1", "TIDY3D_MICROWAVE__SUPPRESS_RF_LICENSE_WARNING=true"]
 doctest_optionflags = "NORMALIZE_WHITESPACE ELLIPSIS"
 norecursedirs = [
   "tests/_test_local",

tests/conftest.py

@@ -36,6 +36,13 @@ def reset_logger():
     set_logging_level(DEFAULT_LEVEL)
 
 
+@pytest.fixture(autouse=True)
+def clear_log_cache():
+    """Ensure log-once cache does not leak between tests."""
+    td.log._static_cache.clear()
+    yield
+
+
 @pytest.fixture
 def check_grads_with_tolerance(monkeypatch):
     @unary_to_nary

tests/test_components/test_microwave.py

@@ -1783,3 +1783,14 @@ def test_impedance_calculator_mode_direction_handling():
     # Both should produce valid impedance values
     assert hasattr(impedance_mode_solver, "values")
     assert hasattr(impedance_mode, "values")
+
+
+def test_RF_license_suppression():
+    """Ensure license warnings are being emitted properly and default instantiations avoid the warning."""
+    original_setting = td.config.microwave.suppress_rf_license_warning
+    td.config.microwave.suppress_rf_license_warning = False
+    with AssertLogLevel("WARNING", contains_str="new license requirements"):
+        mode_spec = td.MicrowaveModeSpec()
+    with AssertLogLevel(None):
+        mode_spec = td.MicrowaveModeSpec._default_without_license_warning()
+    td.config.microwave.suppress_rf_license_warning = original_setting

tidy3d/components/microwave/base.py

@@ -7,7 +7,6 @@
 from tidy3d.components.base import Tidy3dBaseModel
 from tidy3d.config import config
 from tidy3d.log import log
-from tidy3d.utils import is_running_pytest
 
 
 class MicrowaveBaseModel(Tidy3dBaseModel):
@@ -17,8 +16,8 @@ class MicrowaveBaseModel(Tidy3dBaseModel):
     def _warn_rf_license(cls, values):
         from tidy3d.config import config
 
-        # Skip warning during test runs or when globally suppressed via config
-        if not is_running_pytest() and not config.suppress_rf_license_warning:
+        # Skip warning when globally suppressed via config
+        if not config.microwave.suppress_rf_license_warning:
             log.warning(
                 "ℹ️ ⚠️ RF simulations are subject to new license requirements in the future. "
                 "You have instantiated at least one RF-specific component.",
@@ -29,10 +28,10 @@ def _warn_rf_license(cls, values):
     @classmethod
     def _default_without_license_warning(cls) -> MicrowaveBaseModel:
         """Internal helper factory function for classes inheriting from ``MicrowaveBaseModel``."""
-        if config.suppress_rf_license_warning is True:
+        if config.microwave.suppress_rf_license_warning is True:
             return cls()
         else:
-            config.suppress_rf_license_warning = True
-            default_contructed = cls()
-            config.suppress_rf_license_warning = False
-            return default_contructed
+            config.microwave.suppress_rf_license_warning = True
+            default_constructed = cls()
+            config.microwave.suppress_rf_license_warning = False
+            return default_constructed