test: check mode value

Author: Rogdham

CHANGELOG.md

@@ -26,6 +26,7 @@ adheres to [Semantic Versioning](https://semver.org/).
 
 ### :house: Internal
 
+- Test the `mode` attribute of objects returned by `xz.open`/`XZFile`
 - Minor improvements in some docstrings
 
 ## [0.3.1] - 2021-12-26

src/xz/file.py

@@ -70,7 +70,7 @@ def __init__(
 
         super().__init__()
 
-        self.mode, self._readable, self._writable = parse_mode(mode)
+        self._mode, self._readable, self._writable = parse_mode(mode)
 
         # create strategy
         if block_read_strategy is None:
@@ -83,7 +83,7 @@ def __init__(
         # get fileobj
         if isinstance(filename, (str, bytes, os.PathLike)):
             # pylint: disable=consider-using-with, unspecified-encoding
-            self.fileobj = cast(BinaryIO, open(filename, self.mode + "b"))
+            self.fileobj = cast(BinaryIO, open(filename, self._mode + "b"))
             self._close_fileobj = True
         elif hasattr(filename, "read"):  # weak check but better than nothing
             self.fileobj = filename
@@ -99,18 +99,18 @@ def __init__(
             raise ValueError("filename is not writable")
 
         # init
-        if self.mode[0] in "wx":
+        if self._mode[0] in "wx":
             self.fileobj.truncate(0)
         if self._readable:
             self._init_parse()
-        if self.mode[0] == "r" and not self._fileobjs:
+        if self._mode[0] == "r" and not self._fileobjs:
             raise XZError("file: no streams")
 
         self.check = check if check != -1 else DEFAULT_CHECK
         self.preset = preset
         self.filters = filters
 
-        self._close_check_empty = self.mode[0] != "r"
+        self._close_check_empty = self._mode[0] != "r"
 
     @property
     def _last_stream(self) -> Optional[XZStream]:
@@ -122,6 +122,10 @@ def _last_stream(self) -> Optional[XZStream]:
     preset: _LZMAPresetType = proxy_property("preset", "_last_stream")
     filters: _LZMAFiltersType = proxy_property("filters", "_last_stream")
 
+    @property
+    def mode(self) -> str:
+        return self._mode
+
     def readable(self) -> bool:
         return self._readable
 

src/xz/open.py

@@ -52,6 +52,10 @@ def __init__(
         "block_read_strategy", "xz_file"
     )
 
+    @property
+    def mode(self) -> str:
+        return f"{self.xz_file.mode}t"
+
     @wraps(XZFile.change_stream)
     def change_stream(self) -> None:
         self.flush()

tests/unit/test_file.py

@@ -100,6 +100,7 @@ def test_required_abilities(mode: str, ability: str, init_has_ability: bool) ->
     else:
         with XZFile(fileobj, mode=mode) as xzfile:
             assert getattr(xzfile, ability)() == expected_ability
+            assert xzfile.mode == mode.replace("b", "")
 
 
 #

tests/unit/test_open.py

@@ -29,6 +29,7 @@ def test_mode_rb() -> None:
     fileobj = BytesIO(STREAM_BYTES)
 
     with xz_open(fileobj, "rb") as xzfile:
+        assert xzfile.mode == "r"
         assert len(xzfile) == 13
         assert xzfile.stream_boundaries == [0]
         assert xzfile.block_boundaries == [0, 10]
@@ -43,6 +44,7 @@ def test_mode_rt() -> None:
     fileobj = BytesIO(STREAM_BYTES)
 
     with xz_open(fileobj, "rt") as xzfile:
+        assert xzfile.mode == "rt"
         assert xzfile.stream_boundaries == [0]
         assert xzfile.block_boundaries == [0, 10]
 
@@ -188,6 +190,7 @@ def test_mode_wb_check() -> None:
     fileobj = BytesIO()
 
     with xz_open(fileobj, "wb", check=1) as xzfile:
+        assert xzfile.mode == "w"
         xzfile.write(b"\xce\xb1")
         xzfile.change_stream()
         xzfile.check = 4
@@ -204,6 +207,7 @@ def test_mode_wt_check() -> None:
     fileobj = BytesIO()
 
     with xz_open(fileobj, "wt", check=1) as xzfile:
+        assert xzfile.mode == "wt"
         xzfile.write("α")
         xzfile.change_stream()
         xzfile.check = 4