fix: add closed, readable, seekable, writable properties

Author: maxrjones

docs/index.md

@@ -12,7 +12,8 @@ Utilities for interacting with object storage, based on [obspec](https://github.
     [`EagerStoreReader`][obspec_utils.readers.EagerStoreReader], [`BlockStoreReader`][obspec_utils.readers.BlockStoreReader])
     for reading from object stores
 - **`obspec_utils.stores`**: Alternative store implementations (e.g., [`AiohttpStore`][obspec_utils.stores.AiohttpStore] for generic HTTP access)
-- **`obspec_utils.wrappers`**: Composable store wrappers for caching, tracing, and concurrent fetching
+- **`obspec_utils.wrappers`**: Composable store wrappers for [caching][obspec_utils.wrappers.CachingReadableStore],
+    [tracing][obspec_utils.wrappers.TracingReadableStore], and [concurrent fetching][obspec_utils.wrappers.SplittingReadableStore]
 - **`obspec_utils.registry`**: [`ObjectStoreRegistry`][obspec_utils.registry.ObjectStoreRegistry] for managing multiple stores and resolving URLs
 
 ## Design Philosophy

pyproject.toml

@@ -59,6 +59,7 @@ xarray = [
   "h5netcdf",
   "h5py",
   "cftime",
+  "scipy",
 ]
 fsspec = [
   "s3fs",
@@ -101,3 +102,8 @@ exclude_lines = [
   "if __name__ == .__main__.:",
   "if TYPE_CHECKING:",
 ]
+
+[tool.pytest.ini_options]
+markers = [
+  "network: marks tests as requiring network access (run with --network)",
+]

src/obspec_utils/readers/_block.py

@@ -87,6 +87,7 @@ def __init__(
         self._max_cached_blocks = max_cached_blocks
         self._position = 0
         self._size: int | None = None
+        self._closed = False
         # LRU cache: OrderedDict with block_index -> bytes
         self._cache: OrderedDict[int, bytes] = OrderedDict()
 
@@ -242,9 +243,27 @@ def tell(self) -> int:
         """
         return self._position
 
+    @property
+    def closed(self) -> bool:
+        """Return True if the reader has been closed."""
+        return self._closed
+
+    def readable(self) -> bool:
+        """Return True, indicating this reader supports reading."""
+        return True
+
+    def seekable(self) -> bool:
+        """Return True, indicating this reader supports seeking."""
+        return True
+
+    def writable(self) -> bool:
+        """Return False, indicating this reader does not support writing."""
+        return False
+
     def close(self) -> None:
         """Close the reader and release the block cache."""
         self._cache.clear()
+        self._closed = True
 
     def __enter__(self) -> "BlockStoreReader":
         """Enter the context manager."""

src/obspec_utils/readers/_buffered.py

@@ -74,6 +74,7 @@ def __init__(
         self._buffer_size = buffer_size
         self._position = 0
         self._size: int | None = None
+        self._closed = False
         # Read-ahead buffer
         self._buffer = b""
         self._buffer_start = 0
@@ -194,10 +195,28 @@ def tell(self) -> int:
         """
         return self._position
 
+    @property
+    def closed(self) -> bool:
+        """Return True if the reader has been closed."""
+        return self._closed
+
+    def readable(self) -> bool:
+        """Return True, indicating this reader supports reading."""
+        return True
+
+    def seekable(self) -> bool:
+        """Return True, indicating this reader supports seeking."""
+        return True
+
+    def writable(self) -> bool:
+        """Return False, indicating this reader does not support writing."""
+        return False
+
     def close(self) -> None:
         """Close the reader and release the read-ahead buffer."""
         self._buffer = b""
         self._buffer_start = 0
+        self._closed = True
 
     def __enter__(self) -> "BufferedStoreReader":
         """Enter the context manager."""

src/obspec_utils/readers/_eager.py

@@ -95,6 +95,7 @@ def __init__(
         """
         self._store = store
         self._path = path
+        self._closed = False
 
         # Determine file size if not provided
         if file_size is None:
@@ -155,9 +156,27 @@ def tell(self) -> int:
         """Return the current position in the cached file."""
         return self._buffer.tell()
 
+    @property
+    def closed(self) -> bool:
+        """Return True if the reader has been closed."""
+        return self._closed
+
+    def readable(self) -> bool:
+        """Return True, indicating this reader supports reading."""
+        return True
+
+    def seekable(self) -> bool:
+        """Return True, indicating this reader supports seeking."""
+        return True
+
+    def writable(self) -> bool:
+        """Return False, indicating this reader does not support writing."""
+        return False
+
     def close(self) -> None:
         """Close the reader and release the in-memory buffer."""
         self._buffer = io.BytesIO(b"")
+        self._closed = True
 
     def __enter__(self) -> "EagerStoreReader":
         """Enter the context manager."""

tests/conftest.py

@@ -6,6 +6,25 @@
 import xarray as xr
 
 
+def pytest_addoption(parser):
+    parser.addoption(
+        "--network",
+        action="store_true",
+        default=False,
+        help="run tests that require network access",
+    )
+
+
+def pytest_collection_modifyitems(config, items):
+    if config.getoption("--network"):
+        # --network given: do not skip network tests
+        return
+    skip_network = pytest.mark.skip(reason="need --network option to run")
+    for item in items:
+        if "network" in item.keywords:
+            item.add_marker(skip_network)
+
+
 @pytest.fixture(scope="session")
 def container():
     import docker

tests/test_readers.py

@@ -560,3 +560,66 @@ def test_old_parameters_work(self):
     def test_is_subclass_of_block_store_reader(self):
         """ParallelStoreReader should be a subclass of BlockStoreReader."""
         assert issubclass(ParallelStoreReader, BlockStoreReader)
+
+
+# =============================================================================
+# HTTP Store / xarray integration tests
+# =============================================================================
+
+
+@pytest.mark.parametrize("ReaderClass", ALL_READERS)
+def test_reader_closed_property(ReaderClass):
+    """Test that readers have a closed property for file-like compatibility."""
+    memstore = MemoryStore()
+    memstore.put("test.txt", b"hello world")
+
+    reader = ReaderClass(memstore, "test.txt")
+    assert reader.closed is False
+
+    reader.close()
+    assert reader.closed is True
+
+
+@pytest.mark.parametrize("ReaderClass", ALL_READERS)
+def test_reader_closed_property_with_context_manager(ReaderClass):
+    """Test that closed property is True after exiting context manager."""
+    memstore = MemoryStore()
+    memstore.put("test.txt", b"hello world")
+
+    with ReaderClass(memstore, "test.txt") as reader:
+        assert reader.closed is False
+
+    assert reader.closed is True
+
+
+@pytest.mark.parametrize("ReaderClass", ALL_READERS)
+def test_reader_readable(ReaderClass):
+    """Test that readers report as readable."""
+    memstore = MemoryStore()
+    memstore.put("test.txt", b"hello world")
+
+    reader = ReaderClass(memstore, "test.txt")
+    assert reader.readable() is True
+    reader.close()
+
+
+@pytest.mark.parametrize("ReaderClass", ALL_READERS)
+def test_reader_seekable(ReaderClass):
+    """Test that readers report as seekable."""
+    memstore = MemoryStore()
+    memstore.put("test.txt", b"hello world")
+
+    reader = ReaderClass(memstore, "test.txt")
+    assert reader.seekable() is True
+    reader.close()
+
+
+@pytest.mark.parametrize("ReaderClass", ALL_READERS)
+def test_reader_writable(ReaderClass):
+    """Test that readers report as not writable."""
+    memstore = MemoryStore()
+    memstore.put("test.txt", b"hello world")
+
+    reader = ReaderClass(memstore, "test.txt")
+    assert reader.writable() is False
+    reader.close()

tests/test_xarray.py

@@ -18,3 +18,37 @@ def test_reader_with_xarray(local_netcdf4_file, ReaderClass) -> None:
     reader = ReaderClass(store=LocalStore(), path=local_netcdf4_file)
     ds_obstore = xr.open_dataset(reader, engine="h5netcdf")
     xr.testing.assert_allclose(ds_fsspec, ds_obstore)
+
+
+@pytest.mark.network
+def test_eager_reader_xarray_http_store():
+    """
+    Regression test: EagerStoreReader works with HTTPStore and xarray.
+
+    This tests that:
+    1. HTTPStore can fetch remote files
+    2. EagerStoreReader correctly buffers the data
+    3. The reader has the 'closed' property required by scipy/xarray
+    4. xarray can open the dataset using the scipy engine
+    """
+    pytest.importorskip("xarray")
+    import xarray as xr
+    from obstore.store import HTTPStore
+
+    store = HTTPStore.from_url(
+        "https://raw.githubusercontent.com/pydata/xarray-data/refs/heads/master/"
+    )
+    with EagerStoreReader(store, "air_temperature.nc") as reader:
+        # Verify reader has data
+        assert len(reader._buffer.getvalue()) > 0
+
+        # Verify closed property exists and is False
+        assert reader.closed is False
+
+        # Open with xarray (scipy engine for NetCDF Classic format)
+        ds = xr.open_dataset(reader, engine="scipy")
+        assert "air" in ds.data_vars
+        ds.close()
+
+    # Verify closed is True after context exit
+    assert reader.closed is True