Merge pull request #56 from InvestmentSystems/minor-improvements

Add test to assert on exception raised by resolve_dtype_iter

Author: gdevanla

src/_arraykit.c

@@ -120,6 +120,7 @@ AK_ResolveDTypeIter(PyObject *dtypes)
 {
     PyObject *iterator = PyObject_GetIter(dtypes);
     if (iterator == NULL) {
+        // No need to set exception here. GetIter already sets TypeError
         return NULL;
     }
     PyArray_Descr *resolved = NULL;
@@ -147,6 +148,10 @@ AK_ResolveDTypeIter(PyObject *dtypes)
         }
     }
     Py_DECREF(iterator);
+    if (!resolved) {
+        // this could happen if this function gets an empty tuple
+        PyErr_SetString(PyExc_ValueError, "iterable passed to resolve dtypes is empty");
+    }
     return resolved;
 }
 

test/test_util.py

@@ -1,3 +1,4 @@
+import pytest
 import collections
 import datetime
 import unittest
@@ -117,6 +118,14 @@ def test_resolve_dtype_iter_a(self) -> None:
         self.assertEqual(resolve_dtype_iter((a3.dtype, a5.dtype)).kind, 'U')
         self.assertEqual(resolve_dtype_iter((a3.dtype, a5.dtype)).itemsize, 40)
 
+        with pytest.raises(TypeError):
+            resolve_dtype_iter((a3.dtype, int))
+
+        self.assertEqual(resolve_dtype_iter((a1.dtype,)), a1.dtype)
+
+        with pytest.raises(ValueError):
+            resolve_dtype_iter(())
+
     #---------------------------------------------------------------------------
 
     def test_shape_filter_a(self) -> None: