refc: replace assert statements

pyproject.toml

@@ -225,6 +225,7 @@ select = [
   "C",      # flake8-comprehensions
   "B",      # flake8-bugbear
   "UP",
+  "S101",   # do not use asserts
   "NPY201", # numpy 2.* compatibility check
 ]
 ignore = [

tests/ruff.toml

@@ -9,4 +9,5 @@ extend-ignore = [
     "E402", # module-level import not at top of file
     "E731", # lambda assignment
     "F841", # unused local variable
+    "S101", # asserts allowed in tests
 ]

tidy3d/components/geometry/base.py

@@ -679,7 +679,8 @@ def parse_xyz_kwargs(**xyz) -> Tuple[Axis, float]:
             Index into xyz axis (0,1,2) and position along that axis.
         """
         xyz_filtered = {k: v for k, v in xyz.items() if v is not None}
-        assert len(xyz_filtered) == 1, "exactly one kwarg in [x,y,z] must be specified."
+        if len(xyz_filtered) != 1:
+            raise ValueError("exactly one kwarg in [x,y,z] must be specified.")
         axis_label, position = list(xyz_filtered.items())[0]
         axis = "xyz".index(axis_label)
         return axis, position
@@ -3216,7 +3217,8 @@ def compute_derivatives(self, derivative_info: DerivativeInfo) -> AutogradFieldM
             )
             vjp_dict_geo = geo.compute_derivatives(geo_info)
             grad_vjp_values = list(vjp_dict_geo.values())
-            assert len(grad_vjp_values) == 1, "Got multiple gradients for single geometry field."
+            if len(grad_vjp_values) != 1:
+                raise AssertionError("Got multiple gradients for single geometry field.")
             grad_vjps[field_path] = grad_vjp_values[0]
 
         return grad_vjps

tidy3d/components/geometry/polyslab.py

@@ -1373,9 +1373,8 @@ def _surface_area(self, bounds: Bound) -> float:
     def compute_derivatives(self, derivative_info: DerivativeInfo) -> AutogradFieldMap:
         """Compute the adjoint derivatives for this object."""
 
-        assert derivative_info.paths == [
-            ("vertices",)
-        ], "only support derivative wrt 'PolySlab.vertices'."
+        if derivative_info.paths != [("vertices",)]:
+            raise ValueError("only support derivative wrt 'PolySlab.vertices'.")
 
         vjp_vertices = self.compute_derivative_vertices(derivative_info=derivative_info)
 
@@ -1397,7 +1396,8 @@ def compute_derivative_vertices(self, derivative_info: DerivativeInfo) -> Traced
         edge_centers_axis = self.center_axis * np.ones(num_vertices)
         edge_centers_xyz = self.unpop_axis_vect(edge_centers_axis, edge_centers_plane)
 
-        assert edge_centers_xyz.shape == (num_vertices, 3), "something bad happened"
+        if edge_centers_xyz.shape != (num_vertices, 3):
+            raise AssertionError("something bad happened")
 
         # compute the E and D fields at the edge centers
         E_der_at_edges = self.der_at_centers(

tidy3d/components/grid/grid.py

@@ -517,7 +517,8 @@ def discretize_inds(self, box: Box, extend: bool = False) -> List[Tuple[int, int
         # for each dimension
         for axis, (pt_min, pt_max) in enumerate(zip(pts_min, pts_max)):
             bound_coords = np.array(boundaries.to_list[axis])
-            assert pt_min <= pt_max, "min point was greater than max point"
+            if pt_min > pt_max:
+                raise AssertionError("min point was greater than max point")
 
             # index of smallest coord greater than pt_max
             inds_gt_pt_max = np.where(bound_coords > pt_max)[0]

tidy3d/components/simulation.py

@@ -1258,7 +1258,12 @@ def get_dls(geom: Geometry, axis: Axis, num_dls: int) -> List[float]:
         def snap_to_grid(geom: Geometry, axis: Axis) -> Geometry:
             """Snap a 2D material to the Yee grid."""
             center = get_bounds(geom, axis)[0]
-            assert get_bounds(geom, axis)[0] == get_bounds(geom, axis)[1]
+            if get_bounds(geom, axis)[0] != get_bounds(geom, axis)[1]:
+                raise AssertionError(
+                    "Unexpected error encountered while processing 2D material. "
+                    "The upper and lower bounds of the geometry in the normal direction are not equal. "
+                    "If you encounter this error, please create an issue in the Tidy3D github repository."
+                )
             snapped_center = snap_coordinate_to_grid(self.grid, center, axis)
             return geom._update_from_bounds(bounds=(snapped_center, snapped_center), axis=axis)
 

tidy3d/plugins/dispersion/fit.py

@@ -167,7 +167,8 @@ def _unpack_coeffs(coeffs):
         Tuple[np.ndarray[complex], np.ndarray[complex]]
             "a" and "c" poles for the PoleResidue model.
         """
-        assert len(coeffs) % 4 == 0, "len(coeffs) must be multiple of 4."
+        if len(coeffs) % 4 != 0:
+            raise ValueError(f"len(coeffs) must be multiple of 4, got {len(coeffs)=}.")
 
         a_real = coeffs[0::4]
         a_imag = coeffs[1::4]
@@ -692,8 +693,10 @@ def from_file(cls, fname: str, **loadtxt_kwargs) -> DispersionFitter:
             A :class:`DispersionFitter` instance.
         """
         data = np.loadtxt(fname, **loadtxt_kwargs)
-        assert len(data.shape) == 2, "data must contain [wavelength, ndata, kdata] in columns"
-        assert data.shape[-1] in (2, 3), "data must have either 2 or 3 rows (if k data)"
+        if len(data.shape) != 2:
+            raise ValueError("data must contain [wavelength, ndata, kdata] in columns")
+        if data.shape[-1] not in (2, 3):
+            raise ValueError("data must have either 2 or 3 rows (if k data)")
         if data.shape[-1] == 2:
             wvl_um, n_data = data.T
             k_data = None

tidy3d/plugins/microwave/custom_path_integrals.py

@@ -124,7 +124,11 @@ def compute_integral(
         elif isinstance(em_field, FieldTimeData):
             return TimeDataArray(data=result.data, coords=result.coords)
         else:
-            assert isinstance(em_field, ModeSolverData)
+            if not isinstance(em_field, ModeSolverData):
+                raise TypeError(
+                    f"Unsupported 'em_field' type: {type(em_field)}. "
+                    "Expected one of 'FieldData', 'FieldTimeData', 'ModeSolverData'."
+                )
             return FreqModeDataArray(data=result.data, coords=result.coords)
 
     @staticmethod

tidy3d/plugins/microwave/path_integrals.py

@@ -123,7 +123,12 @@ def compute_integral(self, scalar_field: EMScalarFieldType) -> IntegralResultTyp
         elif isinstance(scalar_field, ScalarFieldTimeDataArray):
             return TimeDataArray(data=result.data, coords=result.coords)
         else:
-            assert isinstance(scalar_field, ScalarModeFieldDataArray)
+            if not isinstance(scalar_field, ScalarModeFieldDataArray):
+                raise TypeError(
+                    f"Unsupported 'scalar_field' type: {type(scalar_field)}. "
+                    "Expected one of 'ScalarFieldDataArray', 'ScalarFieldTimeDataArray', "
+                    "'ScalarModeFieldDataArray'."
+                )
             return FreqModeDataArray(data=result.data, coords=result.coords)
 
     def _get_field_along_path(self, scalar_field: EMScalarFieldType) -> EMScalarFieldType:

tidy3d/plugins/smatrix/component_modelers/base.py

@@ -245,7 +245,11 @@ def ab_to_s(a_matrix: DataArray, b_matrix: DataArray) -> DataArray:
         """Get the scattering matrix given the power wave matrices."""
 
         # move the input and output port dimensions to the end, for ease of matrix operations
-        assert a_matrix.dims == b_matrix.dims
+        if a_matrix.dims != b_matrix.dims:
+            raise ValueError(
+                "'a_matrix' and 'b_matrix' must have the same number of dimensions, "
+                f"got {a_matrix.dims=} and {b_matrix.dims=}"
+            )
         dims = list(a_matrix.dims)
         dims.append(dims.pop(dims.index("port_out")))
         dims.append(dims.pop(dims.index("port_in")))

tidy3d/plugins/smatrix/ports/rectangular_lumped.py

@@ -194,9 +194,12 @@ def compute_current(self, sim_data: SimulationData) -> FreqDataArray:
         inject_center = h_cap_coords_along_injection[orth_index]
         # Some sanity checks, tangent H field coordinates should be directly above
         # and below the coordinates of the resistive sheet
-        assert orth_index > 0
-        assert inject_center < h_coords_along_injection[orth_index]
-        assert h_coords_along_injection[orth_index - 1] < inject_center
+        if orth_index <= 0:
+            raise AssertionError
+        if inject_center >= h_coords_along_injection[orth_index]:
+            raise AssertionError
+        if h_coords_along_injection[orth_index - 1] >= inject_center:
+            raise AssertionError
         # Distance between the h1_field and h2_field, a single cell size
         dcap = h_coords_along_injection[orth_index] - h_coords_along_injection[orth_index - 1]
 

tidy3d/web/api/autograd/autograd.py

@@ -655,7 +655,8 @@ def postprocess_adj(
         # todo: handle multi-frequency, move to a property?
         frequencies = {src.source_time.freq0 for src in sim_data_adj.simulation.sources}
         frequencies = list(frequencies)
-        assert len(frequencies) == 1, "Multiple adjoint freqs found"
+        if len(frequencies) != 1:
+            raise RuntimeError("Multiple adjoint frequencies found.")
         freq_adj = frequencies[0]
 
         eps_in = np.mean(structure.medium.eps_model(freq_adj))

tidy3d/web/api/material_fitter.py

@@ -73,8 +73,10 @@ def submit(cls, fitter: DispersionFitter, options: FitterOptions) -> MaterialFit
         options: FitterOptions
             fitter options
         """
-        assert fitter
-        assert options
+        if not isinstance(fitter, DispersionFitter):
+            raise TypeError(f"fitter must be an instance of 'DispersionFitter', got {type(fitter)}")
+        if not isinstance(options, FitterOptions):
+            raise TypeError(f"options must be an instance of 'FitterOptions', got {type(options)}")
         data = np.asarray(list(zip(fitter.wvl_um, fitter.n_data, fitter.k_data)))
         with tempfile.NamedTemporaryFile(suffix=".csv") as temp:
             np.savetxt(temp, data, delimiter=",", header="Wavelength,n,k")