Raise TypeError instead of panic on doing fetch_tile from striped TIFFs (#99)

Avoid panic when running `.fetch_tile()` on a striped TIFF (that does not have tiles).

Author: weiji14

python/src/tiff.rs

@@ -3,7 +3,7 @@ use std::sync::Arc;
 use async_tiff::metadata::{PrefetchBuffer, TiffMetadataReader};
 use async_tiff::reader::AsyncFileReader;
 use async_tiff::TIFF;
-use pyo3::exceptions::{PyFileNotFoundError, PyIndexError};
+use pyo3::exceptions::{PyFileNotFoundError, PyIndexError, PyTypeError};
 use pyo3::prelude::*;
 use pyo3::types::PyType;
 use pyo3_async_runtimes::tokio::future_into_py;
@@ -69,7 +69,11 @@ impl PyTIFF {
             // TODO: avoid this clone; add Arc to underlying rust code?
             .clone();
         future_into_py(py, async move {
-            let tile = ifd.fetch_tile(x, y, reader.as_ref()).await.unwrap();
+            let tile = ifd
+                .fetch_tile(x, y, reader.as_ref())
+                .await
+                .map_err(|err| PyTypeError::new_err(err.to_string()))?;
+
             Ok(PyTile::new(tile))
         })
     }
@@ -91,7 +95,10 @@ impl PyTIFF {
             // TODO: avoid this clone; add Arc to underlying rust code?
             .clone();
         future_into_py(py, async move {
-            let tiles = ifd.fetch_tiles(&x, &y, reader.as_ref()).await.unwrap();
+            let tiles = ifd
+                .fetch_tiles(&x, &y, reader.as_ref())
+                .await
+                .map_err(|err| PyTypeError::new_err(err.to_string()))?;
             let py_tiles = tiles.into_iter().map(PyTile::new).collect::<Vec<_>>();
             Ok(py_tiles)
         })

python/tests/test_exceptions.py

@@ -0,0 +1,22 @@
+"""
+Unit tests to ensure that proper errors are raised instead of a panic.
+"""
+
+import pytest
+from async_tiff.store import HTTPStore
+
+from async_tiff import TIFF
+
+
+async def test_raise_typeerror_fetch_tile_striped_tiff():
+    """
+    Ensure that a TypeError is raised when trying to fetch a tile from a striped TIFF.
+    """
+    store = HTTPStore(url="https://github.com/")
+    path = "OSGeo/gdal/raw/refs/tags/v3.11.0/autotest/gdrivers/data/gtiff/int8.tif"
+
+    tiff = await TIFF.open(path=path, store=store)
+    assert len(tiff.ifds) >= 1
+
+    with pytest.raises(TypeError):
+        await tiff.fetch_tile(0, 0, 0)