Test more code paths on igzip_threaded

Author: rhpvorderman

src/isal/igzip_threaded.py

@@ -129,9 +129,6 @@ def readinto(self, b):
     def readable(self) -> bool:
         return True
 
-    def writable(self) -> bool:
-        return False
-
     def tell(self) -> int:
         if self._closed:
             raise ValueError("I/O operation on closed file")

tests/test

@@ -87,10 +87,32 @@ def test_close_reader():
     f = igzip_threaded.open(TEST_FILE, "rb")
     f.close()
     assert f.closed
+    # Make sure double closing does not raise errors
+    f.close()
 
 
 def test_close_writer():
     raw = tempfile.TemporaryFile()
     f = igzip_threaded.open(raw, "wb")
     f.close()
     assert f.closed
+    # Make sure double closing does not raise errors
+    f.close()
+
+
+def test_reader_not_writable():
+    with igzip_threaded.open(TEST_FILE, "rb") as f:
+        assert not f.writable()
+
+
+def test_writer_not_readable():
+    with tempfile.TemporaryFile(mode="wb") as tmp:
+        with igzip_threaded.open(tmp, "wb") as f:
+            assert not f.readable()
+
+
+def test_writer_wrong_level():
+    with pytest.raises(ValueError) as error:
+        igzip_threaded.open("test", mode="wb", compresslevel=42)
+    error.match("Invalid compression level")
+    error.match("42")