add failure case tests for region parser

tests/test_parsing.py

@@ -1,8 +1,9 @@
+import pytest
 import os.path
 from guidescanpy.flask.core.parser import region_parser
 
 
-def test_parse_txt(data_folder):
+def test_parse_txt():
     file = "RAD51\nZWF1\nchrII:5000-8000"
     parser = region_parser(file, organism="sacCer3")
     regions = list(region for region in parser)
@@ -58,3 +59,32 @@ def test_parse_gtf(data_folder):
         ("chrII:5000-6000", "chrII", 5000, 6000),
         ("chrII:5866-5888", "chrII", 5866, 5888),
     ]
+
+
+def test_parse_unrecognized_extension(tmp_path):
+    file_path = tmp_path / "sacCer3_regions.csv"
+    file_path.write_text("")
+
+    with pytest.raises(TypeError):
+        region_parser(file_path, organism="sacCer3")
+
+
+def test_parse_txt_empty_input():
+    parser = region_parser("", organism="sacCer3")
+    regions = list(region for region in parser)
+    assert regions == []
+
+
+def test_parse_unknown_gene_only():
+    parser = region_parser("UNKNOWNGENE", organism="sacCer3")
+    regions = list(region for region in parser)
+    assert regions == []
+
+
+def test_parse_unknown_and_real_genes():
+    parser = region_parser("RAD51\nUNKNOWNGENE\nchrII:5000-8000", organism="sacCer3")
+    regions = list(region for region in parser)
+    assert regions == [
+        ("RAD51", "chrV", 349980, 351182),
+        ("chrII:5000-8000", "chrII", 5000, 8000),
+    ]