Attempt at making BAT work on Windows

All BlendPath instances will use forward slashes, and there should be
more use of PurePosixPath instead of Path.

blender_asset_tracer/bpathlib.py

@@ -33,12 +33,12 @@ class BlendPath(bytes):
     """A path within Blender is always stored as bytes."""
 
     def __new__(cls, path):
-        if isinstance(path, pathlib.Path):
+        if isinstance(path, pathlib.PurePath):
             path = str(path).encode('utf-8')
         if not isinstance(path, bytes):
             raise TypeError('path must be bytes or pathlib.Path, but is %r' % path)
 
-        return super().__new__(cls, path)
+        return super().__new__(cls, path.replace(b'\\', b'/'))
 
     @classmethod
     def mkrelative(cls, asset_path: pathlib.Path, bfile_path: pathlib.Path) -> 'BlendPath':
@@ -57,7 +57,7 @@ class BlendPath(bytes):
             bdir_parts.popleft()
             asset_parts.popleft()
 
-        rel_asset = pathlib.Path(*asset_parts)
+        rel_asset = pathlib.PurePath(*asset_parts)
         # TODO(Sybren): should we use sys.getfilesystemencoding() instead?
         rel_bytes = str(rel_asset).encode('utf-8')
         as_bytes = b'//' + len(bdir_parts) * b'../' + rel_bytes
@@ -84,8 +84,8 @@ class BlendPath(bytes):
             raise ValueError("'a / b' only works when 'b' is a relative path")
         return BlendPath(os.path.join(parentpath, self))
 
-    def to_path(self) -> pathlib.Path:
-        """Convert this path to a pathlib.Path.
+    def to_path(self) -> pathlib.PurePath:
+        """Convert this path to a pathlib.PurePath.
 
         Interprets the path as UTF-8, and if that fails falls back to the local
         filesystem encoding.
@@ -98,7 +98,7 @@ class BlendPath(bytes):
             decoded = self.decode('utf8')
         except UnicodeDecodeError:
             decoded = self.decode(sys.getfilesystemencoding())
-        return pathlib.Path(decoded)
+        return pathlib.PurePath(decoded)
 
     def is_blendfile_relative(self) -> bool:
         return self[:2] == b'//'

blender_asset_tracer/trace/result.py

@@ -148,7 +148,7 @@ class BlockUsage:
         """
         if self._abspath is None:
             bpath = self.block.bfile.abspath(self.asset_path)
-            as_path = bpath.to_path()
+            as_path = pathlib.Path(bpath.to_path())
             try:
                 self._abspath = as_path.resolve()
             except FileNotFoundError:

tests/test_bpathlib.py

@@ -1,4 +1,4 @@
-from pathlib import Path
+from pathlib import Path, PurePosixPath
 import unittest
 
 from blender_asset_tracer.bpathlib import BlendPath
@@ -6,11 +6,12 @@ from blender_asset_tracer.bpathlib import BlendPath
 
 class BlendPathTest(unittest.TestCase):
     def test_string_path(self):
-        p = BlendPath(Path('//some/file.blend'))
+        p = BlendPath(PurePosixPath('//some/file.blend'))
+        self.assertEqual('//some/file.blend', str(PurePosixPath('//some/file.blend')))
         self.assertEqual(b'//some/file.blend', p)
 
         p = BlendPath(Path(r'C:\some\file.blend'))
-        self.assertEqual(b'C:\\some\\file.blend', p)
+        self.assertEqual(b'C:/some/file.blend', p)
 
     def test_is_absolute(self):
         self.assertFalse(BlendPath(b'//some/file.blend').is_absolute())

tests/test_pack.py

@@ -162,7 +162,7 @@ class PackTest(AbstractPackTest):
     def test_execute_rewrite(self):
         infile, _ = self._pack_with_rewrite()
 
-        extpath = pathlib.Path('//_outside_project', *self.blendfiles.parts[1:])
+        extpath = pathlib.PurePosixPath('//_outside_project', *self.blendfiles.parts[1:])
         extbpath = bpathlib.BlendPath(extpath)
 
         # Those libraries should be properly rewritten.
@@ -209,8 +209,9 @@ class PackTest(AbstractPackTest):
         seq = ed.get_pointer((b'seqbase', b'first'))
         seq_strip = seq.get_pointer(b'strip')
 
-        as_bytes = str((self.blendfiles / 'imgseq').absolute()).encode()
-        relpath = b'//_outside_project%b' % as_bytes
+        imgseq_path = (self.blendfiles / 'imgseq').absolute()
+        as_bytes = str(imgseq_path.relative_to(imgseq_path.anchor)).encode()
+        relpath = bpathlib.BlendPath(b'//_outside_project') / as_bytes
 
         # The image sequence base path should be rewritten.
         self.assertEqual(b'SQ000210.png', seq[b'name'])