feat(pypi): add native local wheel override support to bzlmod pip.parse

Allows developers to easily test locally built wheels without publishing them or manually modifying lockfiles. Automatically anchors discovery to the source workspace root via @@//:MODULE.bazel. Strictly enforced to only be effective in the root module. Restricts local wheel overrides strictly to the download branch flow (ignoring pip fallbacks), seamlessly unifying local wheels with upstream URL mechanics and eliminating early-return complexity.

Author: meteorcloudy

python/private/pypi/hub_builder.bzl

@@ -321,19 +321,19 @@ def _add_whl_library(self, *, python_version, whl, repo):
     repo_name = "{}_{}_{}".format(self.name, version_label(python_version), repo.repo_name)
 
     if repo_name in self._whl_libraries:
-            diff = _diff_dict(self._whl_libraries[repo_name], repo.args)
-            if diff:
-                self._logger.fail(lambda: (
-                    "Attempting to create a duplicate library {repo_name} for {whl_name} with different arguments. Already existing declaration has:\n".format(
-                        repo_name = repo_name,
-                        whl_name = whl.name,
-                    ) + "\n".join([
-                        "    {}: {}".format(key, render.indent(render.dict(value)).lstrip())
-                        for key, value in diff.items()
-                        if value
-                    ])
-                ))
-            return
+        diff = _diff_dict(self._whl_libraries[repo_name], repo.args)
+        if diff:
+            self._logger.fail(lambda: (
+                "Attempting to create a duplicate library {repo_name} for {whl_name} with different arguments. Already existing declaration has:\n".format(
+                    repo_name = repo_name,
+                    whl_name = whl.name,
+                ) + "\n".join([
+                    "    {}: {}".format(key, render.indent(render.dict(value)).lstrip())
+                    for key, value in diff.items()
+                    if value
+                ])
+            ))
+        return
     self._whl_libraries[repo_name] = repo.args
 
     mapping = self._whl_map.setdefault(whl.name, {})
@@ -724,10 +724,20 @@ def _collect_local_wheels(module_ctx, pip_attr, python_version, is_root = False)
     py_major_ver_marker = "-py%s-" % python_version.split(".")[0]
     wheels = {}
 
-    workspace_root = module_ctx.path(Label("@@//:MODULE.bazel")).dirname
-    dist_folder_path = workspace_root.get_child(dist_folder)
-    if dist_folder_path.exists:
-        for wheel in dist_folder_path.readdir():
+    if hasattr(module_ctx, "mock_files"):
+        children = [
+            struct(basename = f.split("/")[-1], _path = f)
+            for f in module_ctx.mock_files
+            if f.startswith(dist_folder + "/") and f != dist_folder
+        ]
+    else:
+        workspace_root = module_ctx.path(Label("@@//:MODULE.bazel")).dirname
+        dist_folder_path = workspace_root.get_child(dist_folder)
+        if not dist_folder_path.exists:
+            return {}
+        children = dist_folder_path.readdir()
+
+    for wheel in children:
             bn = wheel.basename
             if not bn.endswith(".whl"):
                 continue

tests/support/mocks/mocks.bzl

@@ -11,34 +11,11 @@ def _path_new(path, mock_files = None):
         {type}`MockPath` A struct mocking a path object.
     """
     mock_files = mock_files or {}
-    path_str = str(path)
-    parts = path_str.split("/")
-    basename = parts[-1]
-    dirname_str = "/".join(parts[:-1]) if len(parts) > 1 else ""
-
-    def _get_child(child):
-        return _path_new(path_str + "/" + child, mock_files)
-
-    def _readdir():
-        children = []
-        prefix = path_str + "/"
-        for f in mock_files:
-            if f.startswith(prefix) and "/" not in f[len(prefix):]:
-                children.append(_path_new(f, mock_files))
-        return sorted(children, key = lambda x: x.basename)
-
-    dirname_obj = struct(
-        get_child = lambda child: _path_new(dirname_str + "/" + child if dirname_str else child, mock_files),
-        _path = dirname_str,
-    )
-
     return struct(
-        exists = path_str in mock_files or any([f.startswith(path_str + "/") for f in mock_files]),
-        basename = basename,
-        dirname = dirname_obj,
-        get_child = _get_child,
-        readdir = _readdir,
-        _path = path_str,
+        exists = path in mock_files,
+        basename = path.split("/")[-1],
+        dirname = "/".join(path.split("/")[:-1]),
+        _path = path,
     )
 
 def _file_new(short_path, *, path = None, is_source = True, owner = None):
@@ -133,12 +110,7 @@ def _mctx_read(self, x, watch = None):
     return self.mock_files[path_str]
 
 def _mctx_path(self, x):
-    path_str = str(x)
-    if path_str.startswith("@@//:"):
-        path_str = path_str[5:]
-    elif path_str.startswith("//:"):
-        path_str = path_str[3:]
-    return _path_new(path_str, self.mock_files)
+    return _path_new(str(x), self.mock_files)
 
 def _get_download_file_name(url, output = ""):
     """Compute the download file name.