ADD: Add unit test for tiffreader

Author: adamshephard

tests/test_tiffreader.py

@@ -138,3 +138,38 @@ def __init__(
 
     reader = wsireader.WSIReader.try_tiff(dummy_file, ".tiff", None, None, None)
     assert isinstance(reader, wsireader.VirtualWSIReader)
+
+
+def test_parse_filtercolor_metadata_with_filter_pair() -> None:
+    """Test full parsing including filter pair matching from XML metadata."""
+    # We can't possibly test on all the different types of tiff files, so simulate them.
+    xml_str = """
+    <root>
+        <FilterColors>
+            <FilterColors-k>EM123_EX456</FilterColors-k>
+            <FilterColors-v>255,128,0</FilterColors-v>
+        </FilterColors>
+        <ScanBands-i>
+            <Bands-i>
+                <Name>Channel1</Name>
+            </Bands-i>
+            <FilterPair>
+                <EmissionFilter>
+                    <FixedFilter>
+                        <PartNumber>EM123</PartNumber>
+                    </FixedFilter>
+                </EmissionFilter>
+                <ExcitationFilter>
+                    <FixedFilter>
+                        <PartNumber>EX456</PartNumber>
+                    </FixedFilter>
+                </ExcitationFilter>
+            </FilterPair>
+        </ScanBands-i>
+    </root>
+    """
+    root = ElementTree.fromstring(xml_str)
+    result = wsireader.TIFFWSIReader._parse_filtercolor_metadata(root)
+    assert result is not None
+    assert "Channel1" in result
+    assert result["Channel1"] == (1.0, 128 / 255, 0.0)

tests/test_wsireader.py

@@ -28,7 +28,7 @@
 
 from tiatoolbox import cli, utils
 from tiatoolbox.annotation import SQLiteStore
-from tiatoolbox.utils import imread, tiff_to_fsspec
+from tiatoolbox.utils import imread, postproc_defs, tiff_to_fsspec
 from tiatoolbox.utils.exceptions import FileNotSupportedError
 from tiatoolbox.utils.magic import is_sqlite3
 from tiatoolbox.utils.transforms import imresize, locsize2bounds
@@ -2934,6 +2934,29 @@ def test_visualise_multi_channel(sample_qptiff: Path) -> None:
     # Was 7 channels. Not sure if this is correct. Check this!
 
 
+def test_get_post_proc_variants() -> None:
+    """Test different branches of get_post_proc method."""
+    reader = wsireader.VirtualWSIReader(np.zeros((10, 10, 3)))
+
+    assert callable(reader.get_post_proc(lambda x: x))
+    assert reader.get_post_proc(None) is None
+    assert isinstance(reader.get_post_proc("auto"), postproc_defs.MultichannelToRGB)
+    assert isinstance(
+        reader.get_post_proc("MultichannelToRGB"), postproc_defs.MultichannelToRGB
+    )
+
+    with pytest.raises(ValueError, match="Invalid post-processing function"):
+        reader.get_post_proc("invalid_proc")
+
+
+def test_post_proc_applied() -> None:
+    """Test that post_proc is applied to image region."""
+    reader = wsireader.VirtualWSIReader(np.ones((100, 100, 3), dtype=np.uint8))
+    reader.post_proc = lambda x: x * 0
+    region = reader.read_rect((0, 0), (50, 50))
+    assert np.all(region == 0)
+
+
 def test_fsspec_json_wsi_reader_instantiation() -> None:
     """Test if FsspecJsonWSIReader is instantiated.