bpo-15450: Allow subclassing of dircmp (GH-23424) (#23424)
Co-authored-by: Chris Jerdonek <chris.jerdonek@gmail.com>
diff --git a/Doc/library/filecmp.rst b/Doc/library/filecmp.rst
index 31b9b4a..c60603b 100644
--- a/Doc/library/filecmp.rst
+++ b/Doc/library/filecmp.rst
@@ -173,7 +173,13 @@
.. attribute:: subdirs
A dictionary mapping names in :attr:`common_dirs` to :class:`dircmp`
- objects.
+ instances (or MyDirCmp instances if this instance is of type MyDirCmp, a
+ subclass of :class:`dircmp`).
+
+ .. versionchanged:: 3.10
+ Previously entries were always :class:`dircmp` instances. Now entries
+ are the same type as *self*, if *self* is a subclass of
+ :class:`dircmp`.
.. attribute:: DEFAULT_IGNORES
diff --git a/Lib/filecmp.py b/Lib/filecmp.py
index 7a4da6b..7c47eb0 100644
--- a/Lib/filecmp.py
+++ b/Lib/filecmp.py
@@ -115,7 +115,9 @@ class dircmp:
same_files: list of identical files.
diff_files: list of filenames which differ.
funny_files: list of files which could not be compared.
- subdirs: a dictionary of dircmp objects, keyed by names in common_dirs.
+ subdirs: a dictionary of dircmp instances (or MyDirCmp instances if this
+ object is of type MyDirCmp, a subclass of dircmp), keyed by names
+ in common_dirs.
"""
def __init__(self, a, b, ignore=None, hide=None): # Initialize
@@ -185,14 +187,15 @@ def phase3(self): # Find out differences between common files
self.same_files, self.diff_files, self.funny_files = xx
def phase4(self): # Find out differences between common subdirectories
- # A new dircmp object is created for each common subdirectory,
+ # A new dircmp (or MyDirCmp if dircmp was subclassed) object is created
+ # for each common subdirectory,
# these are stored in a dictionary indexed by filename.
# The hide and ignore properties are inherited from the parent
self.subdirs = {}
for x in self.common_dirs:
a_x = os.path.join(self.left, x)
b_x = os.path.join(self.right, x)
- self.subdirs[x] = dircmp(a_x, b_x, self.ignore, self.hide)
+ self.subdirs[x] = self.__class__(a_x, b_x, self.ignore, self.hide)
def phase4_closure(self): # Recursively call phase4() on subdirectories
self.phase4()
diff --git a/Lib/test/test_filecmp.py b/Lib/test/test_filecmp.py
index ca9b4f3..fa4f67b 100644
--- a/Lib/test/test_filecmp.py
+++ b/Lib/test/test_filecmp.py
@@ -66,6 +66,8 @@ def setUp(self):
for dir in (self.dir, self.dir_same, self.dir_diff, self.dir_ignored):
shutil.rmtree(dir, True)
os.mkdir(dir)
+ subdir_path = os.path.join(dir, 'subdir')
+ os.mkdir(subdir_path)
if self.caseinsensitive and dir is self.dir_same:
fn = 'FiLe' # Verify case-insensitive comparison
else:
@@ -110,6 +112,11 @@ def test_cmpfiles(self):
"Comparing mismatched directories fails")
+ def _assert_lists(self, actual, expected):
+ """Assert that two lists are equal, up to ordering."""
+ self.assertEqual(sorted(actual), sorted(expected))
+
+
def test_dircmp(self):
# Check attributes for comparison of two identical directories
left_dir, right_dir = self.dir, self.dir_same
@@ -117,10 +124,13 @@ def test_dircmp(self):
self.assertEqual(d.left, left_dir)
self.assertEqual(d.right, right_dir)
if self.caseinsensitive:
- self.assertEqual([d.left_list, d.right_list],[['file'], ['FiLe']])
+ self._assert_lists(d.left_list, ['file', 'subdir'])
+ self._assert_lists(d.right_list, ['FiLe', 'subdir'])
else:
- self.assertEqual([d.left_list, d.right_list],[['file'], ['file']])
- self.assertEqual(d.common, ['file'])
+ self._assert_lists(d.left_list, ['file', 'subdir'])
+ self._assert_lists(d.right_list, ['file', 'subdir'])
+ self._assert_lists(d.common, ['file', 'subdir'])
+ self._assert_lists(d.common_dirs, ['subdir'])
self.assertEqual(d.left_only, [])
self.assertEqual(d.right_only, [])
self.assertEqual(d.same_files, ['file'])
@@ -128,6 +138,7 @@ def test_dircmp(self):
expected_report = [
"diff {} {}".format(self.dir, self.dir_same),
"Identical files : ['file']",
+ "Common subdirectories : ['subdir']",
]
self._assert_report(d.report, expected_report)
@@ -136,9 +147,10 @@ def test_dircmp(self):
d = filecmp.dircmp(left_dir, right_dir)
self.assertEqual(d.left, left_dir)
self.assertEqual(d.right, right_dir)
- self.assertEqual(d.left_list, ['file'])
- self.assertEqual(d.right_list, ['file', 'file2'])
- self.assertEqual(d.common, ['file'])
+ self._assert_lists(d.left_list, ['file', 'subdir'])
+ self._assert_lists(d.right_list, ['file', 'file2', 'subdir'])
+ self._assert_lists(d.common, ['file', 'subdir'])
+ self._assert_lists(d.common_dirs, ['subdir'])
self.assertEqual(d.left_only, [])
self.assertEqual(d.right_only, ['file2'])
self.assertEqual(d.same_files, ['file'])
@@ -147,6 +159,7 @@ def test_dircmp(self):
"diff {} {}".format(self.dir, self.dir_diff),
"Only in {} : ['file2']".format(self.dir_diff),
"Identical files : ['file']",
+ "Common subdirectories : ['subdir']",
]
self._assert_report(d.report, expected_report)
@@ -159,9 +172,9 @@ def test_dircmp(self):
d = filecmp.dircmp(left_dir, right_dir)
self.assertEqual(d.left, left_dir)
self.assertEqual(d.right, right_dir)
- self.assertEqual(d.left_list, ['file', 'file2'])
- self.assertEqual(d.right_list, ['file'])
- self.assertEqual(d.common, ['file'])
+ self._assert_lists(d.left_list, ['file', 'file2', 'subdir'])
+ self._assert_lists(d.right_list, ['file', 'subdir'])
+ self._assert_lists(d.common, ['file', 'subdir'])
self.assertEqual(d.left_only, ['file2'])
self.assertEqual(d.right_only, [])
self.assertEqual(d.same_files, ['file'])
@@ -170,6 +183,7 @@ def test_dircmp(self):
"diff {} {}".format(self.dir, self.dir_diff),
"Only in {} : ['file2']".format(self.dir),
"Identical files : ['file']",
+ "Common subdirectories : ['subdir']",
]
self._assert_report(d.report, expected_report)
@@ -183,24 +197,45 @@ def test_dircmp(self):
"diff {} {}".format(self.dir, self.dir_diff),
"Identical files : ['file']",
"Differing files : ['file2']",
+ "Common subdirectories : ['subdir']",
]
self._assert_report(d.report, expected_report)
+ def test_dircmp_subdirs_type(self):
+ """Check that dircmp.subdirs respects subclassing."""
+ class MyDirCmp(filecmp.dircmp):
+ pass
+ d = MyDirCmp(self.dir, self.dir_diff)
+ sub_dirs = d.subdirs
+ self.assertEqual(list(sub_dirs.keys()), ['subdir'])
+ sub_dcmp = sub_dirs['subdir']
+ self.assertEqual(type(sub_dcmp), MyDirCmp)
+
def test_report_partial_closure(self):
left_dir, right_dir = self.dir, self.dir_same
d = filecmp.dircmp(left_dir, right_dir)
+ left_subdir = os.path.join(left_dir, 'subdir')
+ right_subdir = os.path.join(right_dir, 'subdir')
expected_report = [
"diff {} {}".format(self.dir, self.dir_same),
"Identical files : ['file']",
+ "Common subdirectories : ['subdir']",
+ '',
+ "diff {} {}".format(left_subdir, right_subdir),
]
self._assert_report(d.report_partial_closure, expected_report)
def test_report_full_closure(self):
left_dir, right_dir = self.dir, self.dir_same
d = filecmp.dircmp(left_dir, right_dir)
+ left_subdir = os.path.join(left_dir, 'subdir')
+ right_subdir = os.path.join(right_dir, 'subdir')
expected_report = [
"diff {} {}".format(self.dir, self.dir_same),
"Identical files : ['file']",
+ "Common subdirectories : ['subdir']",
+ '',
+ "diff {} {}".format(left_subdir, right_subdir),
]
self._assert_report(d.report_full_closure, expected_report)
diff --git a/Misc/ACKS b/Misc/ACKS
index 43030ca..16bc42f 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -368,6 +368,7 @@
Christopher A. Craig
Jeremy Craven
Laura Creighton
+Nick Crews
Tyler Crompton
Simon Cross
Felipe Cruz
diff --git a/Misc/NEWS.d/next/Library/2020-11-20-10-38-34.bpo-15450.E-y9PA.rst b/Misc/NEWS.d/next/Library/2020-11-20-10-38-34.bpo-15450.E-y9PA.rst
new file mode 100644
index 0000000..dc37406
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-11-20-10-38-34.bpo-15450.E-y9PA.rst
@@ -0,0 +1,2 @@
+Make :class:`filecmp.dircmp` respect subclassing. Now the
+:attr:`filecmp.dircmp.subdirs` behaves as expected when subclassing dircmp.