Update after code review of unit tests pandas-dev#1478

Unit tests for DataFrame.astype merged. Dupliacted those tests for
Series.astype. Both testing deprecation of 'raise_on_error' kwarg.

pandas/tests/frame/test_dtypes.py

@@ -523,19 +523,14 @@ def test_timedeltas(self):
         result = df.get_dtype_counts().sort_values()
         assert_series_equal(result, expected)
 
-    def test_illegal_arg_for_errors_in_astype(self):
+    def test_arg_for_errors_in_astype(self):
         # issue #14878
 
         df = DataFrame([1, 2, 3])
 
         with self.assertRaises(ValueError):
             df.astype(np.float64, errors=True)
 
-    def test_depr_kwarg_produces_future_warning(self):
-        # issue #14878
-
-        df = DataFrame([1, 2, 3])
-
         with tm.assert_produces_warning(FutureWarning):
             df.astype(np.int8, raise_on_error=False)
 

pandas/tests/series/test_dtypes.py

@@ -168,3 +168,16 @@ def test_complexx(self):
         b.real = np.arange(5) + 5
         tm.assert_numpy_array_equal(a + 5, b.real)
         tm.assert_numpy_array_equal(4 * a, b.imag)
+
+    def test_arg_for_errors_in_astype(self):
+        # issue #14878
+
+        sr = Series([1, 2, 3])
+
+        with self.assertRaises(ValueError):
+            sr.astype(np.float64, errors=False)
+
+        with tm.assert_produces_warning(FutureWarning):
+            sr.astype(np.int8, raise_on_error=True)
+
+        sr.astype(np.int8, errors='raise')