atomicwrites: remove dependency

The package has been deprecated. Replace usage with open-coded
replacement. Also copy the test suite for the function.

Lifted from pimutils/khal#1393 (which I also authored).

Fixes: #24689

Author: mathstuf

binder/environment.yml

@@ -11,7 +11,6 @@ dependencies:
 # to requirements/main.yml, and copy it here.
 - aiohttp >=3.11.2
 - asyncssh >=2.14.0,<3.0.0
-- atomicwrites >=1.2.0
 - bcrypt >=4.3.0
 - chardet >=2.0.0
 - cloudpickle >=0.5.0

requirements/main.yml

@@ -9,7 +9,6 @@ channels:
 dependencies:
   - aiohttp >=3.11.2
   - asyncssh >=2.14.0,<3.0.0
-  - atomicwrites >=1.2.0
   - bcrypt >=4.3.0
   - chardet >=2.0.0
   - cloudpickle >=0.5.0

setup.py

@@ -270,7 +270,6 @@ def run(self):
     'aiohttp>=3.11.2',
     'applaunchservices>=0.3.0;platform_system=="Darwin"',
     'asyncssh>=2.14.0,<3.0.0',
-    'atomicwrites>=1.2.0',
     'bcrypt>=4.3.0',
     'chardet>=2.0.0',
     'cloudpickle>=0.5.0',

spyder/dependencies.py

@@ -33,7 +33,6 @@
 AIOHTTP_REQVER = '>=3.11.2'
 APPLAUNCHSERVICES_REQVER = '>=0.3.0'
 ASYNCSSH_REQVER = '>=2.14.0,<3.0.0'
-ATOMICWRITES_REQVER = '>=1.2.0'
 BCRYPT_REQVER = ">=4.3.0"
 CHARDET_REQVER = '>=2.0.0'
 CLOUDPICKLE_REQVER = '>=0.5.0'
@@ -108,10 +107,6 @@
      'package_name': 'asyncssh',
      'features': _('Connect to remote kernels through SSH'),
      'required_version': ASYNCSSH_REQVER},
-    {'modname': "atomicwrites",
-     'package_name': "atomicwrites",
-     'features': _("Atomic file writes in the Editor"),
-     'required_version': ATOMICWRITES_REQVER},
     {'modname': "bcrypt",
      'package_name': "bcrypt",
      'features': _("Decrypt passphrase of SSH key files"),

spyder/tests/test_atomic_write.py

@@ -0,0 +1,93 @@
+# From https://github.com/untitaker/python-atomicwrites/blob/4183999d9b7e81af85dee070d5311299bdf5164c/tests/test_atomicwrites.py
+
+import errno
+import os
+
+from spyder.utils.encoding import atomic_write
+
+import pytest
+
+
+def test_atomic_write(tmpdir):
+    fname = tmpdir.join('ha')
+    for i in range(2):
+        with atomic_write(str(fname), overwrite=True, dir=tmpdir, mode='w') as f:
+            f.write('hoho')
+
+    with pytest.raises(OSError) as excinfo:
+        with atomic_write(str(fname), overwrite=False, dir=tmpdir, mode='w') as f:
+            f.write('haha')
+
+    assert excinfo.value.errno == errno.EEXIST
+
+    assert fname.read() == 'hoho'
+    assert len(tmpdir.listdir()) == 1
+
+
+def test_teardown(tmpdir):
+    fname = tmpdir.join('ha')
+    with pytest.raises(AssertionError):
+        with atomic_write(str(fname), overwrite=True, dir=tmpdir, mode='w'):
+            assert False
+
+    assert not tmpdir.listdir()
+
+
+def test_replace_simultaneously_created_file(tmpdir):
+    fname = tmpdir.join('ha')
+    with atomic_write(str(fname), overwrite=True, dir=tmpdir, mode='w') as f:
+        f.write('hoho')
+        fname.write('harhar')
+        assert fname.read() == 'harhar'
+    assert fname.read() == 'hoho'
+    assert len(tmpdir.listdir()) == 1
+
+
+def test_dont_remove_simultaneously_created_file(tmpdir):
+    fname = tmpdir.join('ha')
+    with pytest.raises(OSError) as excinfo:
+        with atomic_write(str(fname), overwrite=False, dir=tmpdir, mode='w') as f:
+            f.write('hoho')
+            fname.write('harhar')
+            assert fname.read() == 'harhar'
+
+    assert excinfo.value.errno == errno.EEXIST
+    assert fname.read() == 'harhar'
+    assert len(tmpdir.listdir()) == 1
+
+
+# Verify that nested exceptions during rollback do not overwrite the initial
+# exception that triggered a rollback.
+def test_open_reraise(tmpdir):
+    fname = tmpdir.join('ha')
+    with pytest.raises(AssertionError):
+        aw = atomic_write(str(fname), overwrite=False, dir=tmpdir, mode='w')
+        with aw:
+            # Mess with internals, so commit will trigger a ValueError. We're
+            # testing that the initial AssertionError triggered below is
+            # propagated up the stack, not the second exception triggered
+            # during commit.
+            aw.rollback = lambda: 1 / 0
+            # Now trigger our own exception.
+            assert False, "Intentional failure for testing purposes"
+
+
+def test_atomic_write_in_pwd(tmpdir):
+    orig_curdir = os.getcwd()
+    try:
+        os.chdir(str(tmpdir))
+        fname = 'ha'
+        for i in range(2):
+            with atomic_write(str(fname), overwrite=True, dir=tmpdir, mode='w') as f:
+                f.write('hoho')
+
+        with pytest.raises(OSError) as excinfo:
+            with atomic_write(str(fname), overwrite=False, dir=tmpdir, mode='w') as f:
+                f.write('haha')
+
+        assert excinfo.value.errno == errno.EEXIST
+
+        assert open(fname).read() == 'hoho'
+        assert len(tmpdir.listdir()) == 1
+    finally:
+        os.chdir(orig_curdir)

spyder/utils/encoding.py

@@ -13,6 +13,7 @@
 
 # Standard library imports
 from codecs import BOM_UTF8, BOM_UTF16, BOM_UTF32
+import contextlib
 import tempfile
 import locale
 import re
@@ -25,7 +26,6 @@
 
 # Third-party imports
 from chardet.universaldetector import UniversalDetector
-from atomicwrites import atomic_write
 
 # Local imports
 from spyder.py3compat import (is_string, to_text_string, is_binary_string,
@@ -244,6 +244,28 @@ def to_unicode(string):
     return string
 
 
+@contextlib.contextmanager
+def atomic_write(dest, overwrite, dir, mode):
+    """Atomically write a file"""
+    fd, src = tempfile.mkstemp(prefix=os.path.basename(dest), dir=dir)
+    file = os.fdopen(fd, mode=mode)
+
+    try:
+        yield file
+    except Exception:
+        os.unlink(src)
+        raise
+    else:
+        file.flush()
+        file.close()
+
+        if overwrite:
+            os.rename(src, dest)
+        else:
+            os.link(src, dest)
+            os.unlink(src)
+
+
 def write(text, filename, encoding='utf-8', mode='wb'):
     """
     Write 'text' to file ('filename') assuming 'encoding' in an atomic way