Additional tests for date_range inferred resolution

Author: tilovashahrin

pandas/tests/dtypes/test_inference.py

@@ -1810,12 +1810,28 @@ def test_is_datetime_dtypes(self):
         assert is_datetime64_any_dtype("datetime64[ns]")
         assert is_datetime64_any_dtype(ts)
         assert is_datetime64_any_dtype(tsa)
+        
+        result_min = pd.date_range("2013-01-01", periods=3, freq="1min")
+        assert result_min.dtype == 'datetime64[s]'
+
+        result_day = pd.date_range("2013-01-01", periods=3, freq="1D")
+        assert result_day.dtype == 'datetime64[D]'
+
+        result_hour = pd.date_range("2013-01-01", periods=3, freq="1H")
+        assert result_hour.dtype == 'datetime64[h]'
+
+        result_ms = pd.date_range("2013-01-01", periods=3, freq="1ms")
+        assert result_ms.dtype == 'datetime64[ms]'
+
+        result_ns = pd.date_range("2013-01-01", periods=3, freq="1s")
+        assert result_ns.dtype == 'datetime64[ns]'
 
         with tm.assert_produces_warning(DeprecationWarning, match=msg):
             assert not is_datetime64tz_dtype("datetime64")
             assert not is_datetime64tz_dtype("datetime64[ns]")
             assert not is_datetime64tz_dtype(ts)
             assert is_datetime64tz_dtype(tsa)
+        
 
     @pytest.mark.parametrize("tz", ["US/Eastern", "UTC"])
     def test_is_datetime_dtypes_with_tz(self, tz):