Move subclass check into __init_subclass__

src/pyuvdata/uvbeam/analytic_beam.py

@@ -68,6 +68,12 @@ class AnalyticBeam(ABC):
 
     def __init_subclass__(cls):
         """Initialize any imported subclass."""
+        if cls.basis_vector_type not in cls._basis_vec_dict:
+            raise ValueError(
+                f"basis_vector_type for {cls.__name__} is {cls.basis_vector_type}, "
+                f"must be one of {list(cls._basis_vec_dict.keys())}"
+            )
+
         cls.__types__[cls.__name__] = cls
 
     @property
@@ -86,12 +92,6 @@ def __post_init__(self, include_cross_pols):
             for the power beam.
 
         """
-        if self.basis_vector_type not in self._basis_vec_dict:
-            raise ValueError(
-                f"basis_vector_type is {self.basis_vector_type}, must be one of "
-                f"{list(self._basis_vec_dict.keys())}"
-            )
-
         if self.feed_array is not None:
             for feed in self.feed_array:
                 allowed_feeds = ["n", "e", "x", "y", "r", "l"]

tests/uvbeam/test_analytic_beam.py

@@ -316,33 +316,34 @@ def test_beamerrs(beam_kwargs, err_msg):
 
 
 def test_bad_basis_vector_type():
-    class BadBeam(AnalyticBeam):
-        basis_vector_type = "healpix"
-        name = "bad beam"
-
-        def _efield_eval(
-            self, az_array: np.ndarray, za_array: np.ndarray, freq_array: np.ndarray
-        ):
-            """Evaluate the efield at the given coordinates."""
-            data_array = self._get_empty_data_array(az_array, za_array, freq_array)
-            data_array = data_array + 1.0 / np.sqrt(2.0)
-            return data_array
-
-        def _power_eval(
-            self, az_array: np.ndarray, za_array: np.ndarray, freq_array: np.ndarray
-        ):
-            """Evaluate the efield at the given coordinates."""
-            data_array = self._get_empty_data_array(
-                az_array, za_array, freq_array, beam_type="power"
-            )
-            data_array = data_array + 1.0
-            return data_array
-
     with pytest.raises(
         ValueError,
-        match=re.escape("basis_vector_type is healpix, must be one of ['az_za']"),
+        match=re.escape(
+            "basis_vector_type for BadBeam is healpix, must be one of ['az_za']"
+        ),
     ):
-        BadBeam()
+
+        class BadBeam(AnalyticBeam):
+            basis_vector_type = "healpix"
+            name = "bad beam"
+
+            def _efield_eval(
+                self, az_array: np.ndarray, za_array: np.ndarray, freq_array: np.ndarray
+            ):
+                """Evaluate the efield at the given coordinates."""
+                data_array = self._get_empty_data_array(az_array, za_array, freq_array)
+                data_array = data_array + 1.0 / np.sqrt(2.0)
+                return data_array
+
+            def _power_eval(
+                self, az_array: np.ndarray, za_array: np.ndarray, freq_array: np.ndarray
+            ):
+                """Evaluate the efield at the given coordinates."""
+                data_array = self._get_empty_data_array(
+                    az_array, za_array, freq_array, beam_type="power"
+                )
+                data_array = data_array + 1.0
+                return data_array
 
 
 def test_to_uvbeam_errors():