GH-125866: Add tests for nturl2path module

Add `tests.test_nturl2path` to exercise `nturl2path`.

`nturl2path` is currently used by `urllib` and tested by `test_urllib`, but
that will change when we deprecate `nturl2path` and add support for Windows
paths/URLs in `urllib` itself.

Author: barneygale

Lib/nturl2path.py

@@ -3,7 +3,7 @@
 This module only exists to provide OS-specific code
 for urllib.requests, thus do not use directly.
 """
-# Testing is done through test_urllib.
+# Testing is done through test_nturl2path.
 
 def url2pathname(url):
     """OS-specific conversion from a relative URL of the 'file' scheme

Lib/test/test_nturl2path.py

@@ -0,0 +1,103 @@
+import nturl2path
+import unittest
+
+
+class NTURL2PathTest(unittest.TestCase):
+    """Test pathname2url() and url2pathname()"""
+
+    def test_basic(self):
+        # Make sure simple tests pass
+        expected_path = r"parts\of\a\path"
+        expected_url = "parts/of/a/path"
+        result = nturl2path.pathname2url(expected_path)
+        self.assertEqual(expected_url, result,
+                         "pathname2url() failed; %s != %s" %
+                         (result, expected_url))
+        result = nturl2path.url2pathname(expected_url)
+        self.assertEqual(expected_path, result,
+                         "url2pathame() failed; %s != %s" %
+                         (result, expected_path))
+
+    def test_pathname2url(self):
+        # Test special prefixes are correctly handled in pathname2url()
+        fn = nturl2path.pathname2url
+        self.assertEqual(fn('\\\\?\\C:\\dir'), '///C:/dir')
+        self.assertEqual(fn('\\\\?\\unc\\server\\share\\dir'), '//server/share/dir')
+        self.assertEqual(fn("C:"), '///C:')
+        self.assertEqual(fn("C:\\"), '///C:/')
+        self.assertEqual(fn('c:\\a\\b.c'), '///c:/a/b.c')
+        self.assertEqual(fn('C:\\a\\b.c'), '///C:/a/b.c')
+        self.assertEqual(fn('C:\\a\\b.c\\'), '///C:/a/b.c/')
+        self.assertEqual(fn('C:\\a\\\\b.c'), '///C:/a//b.c')
+        self.assertEqual(fn('C:\\a\\b%#c'), '///C:/a/b%25%23c')
+        self.assertEqual(fn('C:\\a\\b\xe9'), '///C:/a/b%C3%A9')
+        self.assertEqual(fn('C:\\foo\\bar\\spam.foo'), "///C:/foo/bar/spam.foo")
+        # NTFS alternate data streams
+        self.assertEqual(fn('C:\\foo:bar'), '///C:/foo%3Abar')
+        self.assertEqual(fn('foo:bar'), 'foo%3Abar')
+        # No drive letter
+        self.assertEqual(fn("\\folder\\test\\"), '///folder/test/')
+        self.assertEqual(fn("\\\\folder\\test\\"), '//folder/test/')
+        self.assertEqual(fn("\\\\\\folder\\test\\"), '///folder/test/')
+        self.assertEqual(fn('\\\\some\\share\\'), '//some/share/')
+        self.assertEqual(fn('\\\\some\\share\\a\\b.c'), '//some/share/a/b.c')
+        self.assertEqual(fn('\\\\some\\share\\a\\b%#c\xe9'), '//some/share/a/b%25%23c%C3%A9')
+        # Alternate path separator
+        self.assertEqual(fn('C:/a/b.c'), '///C:/a/b.c')
+        self.assertEqual(fn('//some/share/a/b.c'), '//some/share/a/b.c')
+        self.assertEqual(fn('//?/C:/dir'), '///C:/dir')
+        self.assertEqual(fn('//?/unc/server/share/dir'), '//server/share/dir')
+        # Round-tripping
+        urls = ['///C:',
+                '///folder/test/',
+                '///C:/foo/bar/spam.foo']
+        for url in urls:
+            self.assertEqual(fn(nturl2path.url2pathname(url)), url)
+
+    def test_url2pathname(self):
+        fn = nturl2path.url2pathname
+        self.assertEqual(fn('/C:/'), 'C:\\')
+        self.assertEqual(fn("///C|"), 'C:')
+        self.assertEqual(fn("///C:"), 'C:')
+        self.assertEqual(fn('///C:/'), 'C:\\')
+        self.assertEqual(fn('/C|//'), 'C:\\\\')
+        self.assertEqual(fn('///C|/path'), 'C:\\path')
+        # No DOS drive
+        self.assertEqual(fn("///C/test/"), '\\C\\test\\')
+        self.assertEqual(fn("////C/test/"), '\\\\C\\test\\')
+        # DOS drive paths
+        self.assertEqual(fn('c:/path/to/file'), 'c:\\path\\to\\file')
+        self.assertEqual(fn('C:/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('C:/path/to/file/'), 'C:\\path\\to\\file\\')
+        self.assertEqual(fn('C:/path/to//file'), 'C:\\path\\to\\\\file')
+        self.assertEqual(fn('C|/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('/C|/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('///C|/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn("///C|/foo/bar/spam.foo"), 'C:\\foo\\bar\\spam.foo')
+        # Colons in URI
+        self.assertEqual(fn('///\u00e8|/'), '\u00e8:\\')
+        self.assertEqual(fn('//host/share/spam.txt:eggs'), '\\\\host\\share\\spam.txt:eggs')
+        self.assertEqual(fn('///c:/spam.txt:eggs'), 'c:\\spam.txt:eggs')
+        # UNC paths
+        self.assertEqual(fn('//server/path/to/file'), '\\\\server\\path\\to\\file')
+        self.assertEqual(fn('////server/path/to/file'), '\\\\server\\path\\to\\file')
+        self.assertEqual(fn('/////server/path/to/file'), '\\\\server\\path\\to\\file')
+        # Localhost paths
+        self.assertEqual(fn('//localhost/C:/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('//localhost/C|/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('//localhost/path/to/file'), '\\path\\to\\file')
+        self.assertEqual(fn('//localhost//server/path/to/file'), '\\\\server\\path\\to\\file')
+        # Percent-encoded forward slashes are preserved for backwards compatibility
+        self.assertEqual(fn('C:/foo%2fbar'), 'C:\\foo/bar')
+        self.assertEqual(fn('//server/share/foo%2fbar'), '\\\\server\\share\\foo/bar')
+        # Round-tripping
+        paths = ['C:',
+                 r'\C\test\\',
+                 r'C:\foo\bar\spam.foo']
+        for path in paths:
+            self.assertEqual(fn(nturl2path.pathname2url(path)), path)
+
+
+
+if __name__ == '__main__':
+    unittest.main()