Normalize databricks paths as part of resolving them (#157)

`Path("/a/b/../c").resolve()` returns `Path("/a/c")`
Databricks paths should behave the same, but currently don't.
This PR fixes the issue, which participates in
databrickslabs/ucx#2882

Progresses databrickslabs/ucx#2882

---------

Co-authored-by: Eric Vergnaud <[email protected]>

src/databricks/labs/blueprint/paths.py

@@ -520,7 +520,23 @@ def resolve(self: P, strict: bool = False) -> P:
         if strict and not absolute.exists():
             msg = f"Path does not exist: {self}"
             raise FileNotFoundError(msg)
-        return absolute
+        # pylint: disable=protected-access
+        return absolute._normalize()
+
+    def _normalize(self: P) -> P:
+        if ".." not in self._path_parts:
+            return self
+        segments: list[str] = []
+        for part in self._path_parts:
+            if part == "..":
+                if segments:
+                    segments.pop()
+            elif part is None or part == '.':
+                continue
+            else:
+                segments.append(part)
+        # pylint: disable=protected-access
+        return self.with_segments(self.anchor, *segments)._normalize()
 
     def absolute(self: P) -> P:
         if self.is_absolute():

tests/integration/test_paths.py

@@ -191,6 +191,22 @@ def test_replace_file(ws, make_random, cls):
         tmp_dir.rmdir(recursive=True)
 
 
+@pytest.mark.parametrize("cls", DATABRICKS_PATHLIKE)
+def test_resolve_is_consistent(ws, cls):
+    path = cls(ws, "/a/b/c") / Path("../../d")
+    resolved = path.resolve()
+    assert resolved == cls(ws, "/a/d")
+    path = cls(ws, "/a/b/c") / "../../d"
+    resolved = path.resolve()
+    assert resolved == cls(ws, "/a/d")
+    resolved = cls(ws, "/a/b/c/../../d").resolve()
+    assert resolved == cls(ws, "/a/d")
+    resolved = cls(ws, "/../d").resolve()
+    assert resolved == cls(ws, "/d")
+    resolved = cls(ws, "/a/b/c/./../../d").resolve()
+    assert resolved == cls(ws, "/a/d")
+
+
 def test_workspace_as_fuse(ws):
     wsp = WorkspacePath(ws, "/Users/foo/bar/baz")
     assert Path("/Workspace/Users/foo/bar/baz") == wsp.as_fuse()