Add other open modes in group creation test (#2840)

* add other open modes in group creation test

Signed-off-by: asim <[email protected]>

* minor fix

Signed-off-by: asim <[email protected]>

* Update tests/test_api.py

Add  else block for write operations only

Co-authored-by: Davis Bennett <[email protected]>

---------

Signed-off-by: asim <[email protected]>
Co-authored-by: Davis Bennett <[email protected]>

Author: asimchoudhary

tests/test_api.py

@@ -209,7 +209,7 @@ def test_save(store: Store, n_args: int, n_kwargs: int) -> None:
         assert isinstance(array, Array)
         assert_array_equal(array[:], data)
     else:
-        save(store, *args, **kwargs)  # type: ignore[arg-type]
+        save(store, *args, **kwargs)  # type: ignore [arg-type]
         group = open(store)
         assert isinstance(group, Group)
         for array in group.array_values():
@@ -1095,25 +1095,31 @@ async def test_open_falls_back_to_open_group_async() -> None:
     assert group.attrs == {"key": "value"}
 
 
-def test_open_mode_write_creates_group(tmp_path: pathlib.Path) -> None:
+@pytest.mark.parametrize("mode", ["r", "r+", "w", "a"])
+def test_open_modes_creates_group(tmp_path: pathlib.Path, mode: str) -> None:
     # https://github.com/zarr-developers/zarr-python/issues/2490
-    zarr_dir = tmp_path / "test.zarr"
-    group = zarr.open(zarr_dir, mode="w")
-    assert isinstance(group, Group)
+    zarr_dir = tmp_path / f"mode-{mode}-test.zarr"
+    if mode in ["r", "r+"]:
+        # Expect FileNotFoundError to be raised if 'r' or 'r+' mode
+        with pytest.raises(FileNotFoundError):
+            zarr.open(store=zarr_dir, mode=mode)
+    else:
+        group = zarr.open(store=zarr_dir, mode=mode)
+        assert isinstance(group, Group)
 
 
 async def test_metadata_validation_error() -> None:
     with pytest.raises(
         MetadataValidationError,
         match="Invalid value for 'zarr_format'. Expected '2, 3, or None'. Got '3.0'.",
     ):
-        await zarr.api.asynchronous.open_group(zarr_format="3.0")  # type: ignore[arg-type]
+        await zarr.api.asynchronous.open_group(zarr_format="3.0")  # type: ignore [arg-type]
 
     with pytest.raises(
         MetadataValidationError,
         match="Invalid value for 'zarr_format'. Expected '2, 3, or None'. Got '3.0'.",
     ):
-        await zarr.api.asynchronous.open_array(shape=(1,), zarr_format="3.0")  # type: ignore[arg-type]
+        await zarr.api.asynchronous.open_array(shape=(1,), zarr_format="3.0")  # type: ignore [arg-type]
 
 
 @pytest.mark.parametrize(