add: unit tests for zipfile2 (#1)

src/cosmofy/zipfile2.py

@@ -19,6 +19,8 @@
 class ZipFile2(ZipFile):
     """Extension of `zipfile.ZipFile` that allows removing members."""
 
+    _writing: bool
+
     # NOTE: This function only works on python >= 3.11
     # def add_dir(self, name: str, mode: int = 0o777, date: datetime = now) -> ZipFile2:
     #     """Add a directory to an archive with permissions."""
@@ -56,7 +58,7 @@ def remove(self, member: Union[str, ZipInfo]) -> ZipFile2:
             raise RuntimeError("remove() requires mode 'a'")
         if not self.fp:
             raise ValueError("Attempt to write to ZIP archive that was already closed")
-        if self._writing:  # type: ignore
+        if self._writing:
             raise ValueError(
                 "Can't write to ZIP archive while an open writing handle exists."
             )
@@ -76,32 +78,30 @@ def remove(self, member: Union[str, ZipInfo]) -> ZipFile2:
         return self
 
     def _remove_member(self, member: ZipInfo) -> ZipFile2:
-        # get a sorted filelist by header offset, in case the dir order
-        # doesn't match the actual entry order
+        """Internal method to remove a member."""
         fp = self.fp
         assert fp
 
+        # sort by header_offset in case central dir has different order
         entry_offset = 0
         filelist = sorted(self.filelist, key=attrgetter("header_offset"))
-        for i in range(len(filelist)):
-            info = filelist[i]
-            # find the target member
-            if info.header_offset < member.header_offset:
+        last_index = len(filelist) - 1
+        for i, info in enumerate(filelist):
+            if info.header_offset < member.header_offset:  # keep going until target
                 continue
 
             # get the total size of the entry
             entry_size = None
-            if i == len(filelist) - 1:
+            if i == last_index:
                 entry_size = self.start_dir - info.header_offset
             else:
                 entry_size = filelist[i + 1].header_offset - info.header_offset
 
-            # found the member, set the entry offset
-            if member == info:
+            if member == info:  # set the entry offset
                 entry_offset = entry_size
                 continue
+            # move all subsequent entries
 
-            # Move entry
             # read the actual entry data
             fp.seek(info.header_offset)
             entry_data = fp.read(entry_size)
@@ -122,14 +122,15 @@ def _remove_member(self, member: ZipInfo) -> ZipFile2:
 
         # seek to the start of the central dir
         fp.seek(self.start_dir)
-
         return self
 
     def _write_end_record(self) -> None:
+        """Write the end record to the file and truncate extra space."""
         super()._write_end_record()  # type: ignore
         if self.fp and hasattr(self.fp, "truncate"):
             self.fp.truncate()
-        else:
+        else:  # pragma: no cover
+            # This is hard to test without messing up other things.
             print(
                 "WARNING: truncate unimplemented, zip WILL be corrupted if you removed a member!"
             )

test/test_zipfile2.py

@@ -0,0 +1,66 @@
+"""Test `zipfile2` edge cases."""
+
+# std
+from unittest.mock import MagicMock
+from unittest.mock import patch
+from zipfile import ZipInfo
+import io
+
+# lib
+import pytest
+
+# pkg
+from cosmofy.zipfile2 import ZipFile2
+
+
+def test_errors() -> None:
+    """Run time errors."""
+    file = ZipFile2(io.BytesIO(), "a")  # to keep from `BadZipFile`
+
+    file.mode = "r"
+    with pytest.raises(RuntimeError):
+        file.remove("fake")
+
+    file.mode = "a"
+    file._writing = True
+    with pytest.raises(ValueError):
+        file.remove("fake")
+
+    file.mode = "a"
+    file._writing = False
+    file.close()
+    with pytest.raises(ValueError):
+        file.remove("fake")
+
+
+@patch("cosmofy.zipfile2.ZipFile2._remove_member")
+@patch("cosmofy.zipfile2.ZipFile2.getinfo")
+def test_remove(_getinfo: MagicMock, _remove_member: MagicMock) -> None:
+    """Test removing a member."""
+    file = ZipFile2(io.BytesIO(), "a")  # to keep from `BadZipFile`
+    info = ZipInfo("to_remove")
+
+    file.remove(info)
+    _remove_member.assert_called_once_with(info)
+
+    file.remove("to_remove")
+    assert _remove_member.called
+    assert _getinfo.called
+
+    file.remove("fake/*")
+    assert _remove_member.called
+
+
+def test_remove_real() -> None:
+    """Remove actual members."""
+    file = ZipFile2(io.BytesIO(), "a")
+
+    file.writestr("real/keep1", b"to be kept")
+    file.writestr("real/remove1", b"to be removed")
+    file.writestr("real/keep2", b"to be kept")
+    file.writestr("real/remove2", b"to be removed")
+    assert len(file.filelist) == 4
+
+    file.remove("real/remove2")
+    file.remove("real/r*")
+    assert len(file.filelist) == 2