TST: Test series construct of dtype timedelta64 #35465 (#47801)

* TST GH35465
Tests for repr of Series with dtype timedelta64

* pre commit test file

* TST GH35465
Tests for Series constructs  with dtype timedelta64

* restore pandas/tests/series/test_repr.py

* perform pre-commit

* use int64 for tests

Author: ntachukwu

pandas/tests/series/test_constructors.py

@@ -1879,6 +1879,28 @@ def test_constructor_bool_dtype_missing_values(self):
         expected = Series(True, index=[0], dtype="bool")
         tm.assert_series_equal(result, expected)
 
+    def test_constructor_dtype_timedelta_alternative_construct(self):
+        # GH#35465
+        result = Series([1000000, 200000, 3000000], dtype="timedelta64[ns]")
+        expected = Series(pd.to_timedelta([1000000, 200000, 3000000], unit="ns"))
+        tm.assert_series_equal(result, expected)
+
+    def test_constructor_dtype_timedelta_ns_s(self):
+        # GH#35465
+        result = Series([1000000, 200000, 3000000], dtype="timedelta64[ns]")
+        expected = Series([1000000, 200000, 3000000], dtype="timedelta64[s]")
+        tm.assert_series_equal(result, expected)
+
+    def test_constructor_dtype_timedelta_ns_s_astype_int64(self):
+        # GH#35465
+        result = Series([1000000, 200000, 3000000], dtype="timedelta64[ns]").astype(
+            "int64"
+        )
+        expected = Series([1000000, 200000, 3000000], dtype="timedelta64[s]").astype(
+            "int64"
+        )
+        tm.assert_series_equal(result, expected)
+
     @pytest.mark.filterwarnings(
         "ignore:elementwise comparison failed:DeprecationWarning"
     )