wip: it seems that due to circular dependencies I cannot auto-detect the values of the extra aliases field to be passed to the hub repo, because I have no visibility into what annotatinos are passed to what hubs, because of how the code is structured today. Lets just ask the user to specify those explicitly

Author: aignas

python/private/pypi/extension.bzl

@@ -68,6 +68,7 @@ def _create_whl_repos(
         pip_attr,
         whl_overrides,
         simpleapi_cache,
+        whl_mods,
         available_interpreters = INTERPRETER_LABELS,
         simpleapi_download = simpleapi_download):
     """create all of the whl repositories
@@ -104,6 +105,7 @@ def _create_whl_repos(
     # containers to aggregate outputs from this function
     whl_map = {}
     exposed_packages = {}
+    extra_aliases = {}
     whl_libraries = {}
 
     # if we do not have the python_interpreter set in the attributes
@@ -138,6 +140,14 @@ def _create_whl_repos(
         for mod, whl_name in pip_attr.whl_modifications.items():
             whl_modifications[normalize_name(whl_name)] = mod
 
+            annotation = json.decode(module_ctx.read(mod))
+            if annotation.additive_build_content:
+                extra_aliases.setdefault(whl_name, {}).update({
+                    line.partition("name = ")[-1].strip("\"',"): True
+                    for line in annotation.build_content.split("\n")
+                    if line.lstrip().beginswith("name = ")
+                })
+
     if pip_attr.experimental_requirement_cycles:
         requirement_cycles = {
             name: [normalize_name(whl_name) for whl_name in whls]
@@ -349,6 +359,7 @@ def _create_whl_repos(
         is_reproducible = is_reproducible,
         whl_map = whl_map,
         exposed_packages = exposed_packages,
+        extra_aliases = extra_aliases,
         whl_libraries = whl_libraries,
     )
 
@@ -433,6 +444,7 @@ You cannot use both the additive_build_content and additive_build_content_file a
     hub_whl_map = {}
     hub_group_map = {}
     exposed_packages = {}
+    extra_aliases = {}
     whl_libraries = {}
 
     is_reproducible = True
@@ -477,11 +489,15 @@ You cannot use both the additive_build_content and additive_build_content_file a
                 pip_attr = pip_attr,
                 simpleapi_cache = simpleapi_cache,
                 whl_overrides = whl_overrides,
+                whl_mods = whl_mods,
                 **kwargs
             )
             hub_whl_map.setdefault(hub_name, {})
             for key, settings in out.whl_map.items():
                 hub_whl_map[hub_name].setdefault(key, []).extend(settings)
+            extra_aliases.setdefault(hub_name, {})
+            for whl_name, extra_aliases in out.extra_aliases.items():
+                extra_aliases[hub_name].setdefault(whl_name, {}).update(extra_aliases)
             exposed_packages.setdefault(hub_name, {}).update(out.exposed_packages)
             whl_libraries.update(out.whl_libraries)
             is_reproducible = is_reproducible and out.is_reproducible
@@ -510,6 +526,13 @@ You cannot use both the additive_build_content and additive_build_content_file a
             for hub_name, group_map in sorted(hub_group_map.items())
         },
         exposed_packages = {k: sorted(v) for k, v in sorted(exposed_packages.items())},
+        extra_aliases = {
+            hub_name: {
+                whl_name: sorted(aliases)
+                for whl_name, aliases in extra_whl_aliases.items()
+            }
+            for hub_name, extra_whl_aliases in extra_aliases.items()
+        },
         whl_libraries = dict(sorted(whl_libraries.items())),
         is_reproducible = is_reproducible,
     )

tests/pypi/extension/extension_tests.bzl

@@ -61,13 +61,37 @@ def _parse_modules(env, **kwargs):
         attrs = dict(
             is_reproducible = subjects.bool,
             exposed_packages = subjects.dict,
+            extra_aliases = subjects.dict,
             hub_group_map = subjects.dict,
             hub_whl_map = subjects.dict,
             whl_libraries = subjects.dict,
             whl_mods = subjects.dict,
         ),
     )
 
+def _whl_mods(
+        *,
+        whl_name,
+        hub_name,
+        additive_build_content = None,
+        additive_build_content_file = None,
+        copy_executables = {},
+        copy_files = {},
+        data = [],
+        data_exclude_glob = [],
+        srcs_exclude_glob = []):
+    return struct(
+        additive_build_content = additive_build_content,
+        additive_build_content_file = additive_build_content_file,
+        copy_executables = copy_executables,
+        copy_files = copy_files,
+        data = data,
+        data_exclude_glob = data_exclude_glob,
+        hub_name = hub_name,
+        srcs_exclude_glob = srcs_exclude_glob,
+        whl_name = whl_name,
+    )
+
 def _parse(
         *,
         hub_name,
@@ -164,11 +188,25 @@ def _test_simple_with_whl_mods(env):
         module_ctx = _mock_mctx(
             _mod(
                 name = "rules_python",
+                whl_mods = [
+                    _whl_mods(
+                        additive_build_content = """\
+filegroup(
+    name = "foo",
+    srcs = ["all"],
+)""",
+                        hub_name = "whl_mods_hub",
+                        whl_name = "simple",
+                    ),
+                ],
                 parse = [
                     _parse(
                         hub_name = "pypi",
                         python_version = "3.15",
                         requirements_lock = "requirements.txt",
+                        whl_modifications = {
+                            "@whl_mods_hub//:simple.json": "simple",
+                        },
                     ),
                 ],
             ),
@@ -182,6 +220,11 @@ def _test_simple_with_whl_mods(env):
 
     pypi.is_reproducible().equals(True)
     pypi.exposed_packages().contains_exactly({"pypi": []})
+    pypi.extra_aliases().contains_exactly({
+        "pypi": {
+            "simple": "foo",
+        }
+    })
     pypi.hub_group_map().contains_exactly({"pypi": {}})
     pypi.hub_whl_map().contains_exactly({"pypi": {
         "simple": [
@@ -196,13 +239,25 @@ def _test_simple_with_whl_mods(env):
     }})
     pypi.whl_libraries().contains_exactly({
         "pypi_315_simple": {
+            "annotation": "@whl_mods_hub//:simple.json",
             "dep_template": "@pypi//{name}:{target}",
             "python_interpreter_target": "unit_test_interpreter_target",
             "repo": "pypi_315",
             "requirement": "simple==0.0.1 --hash=sha256:deadbeef",
         },
     })
-    pypi.whl_mods().contains_exactly({})
+    pypi.whl_mods().contains_exactly({
+        "whl_mods_hub": {
+            "simple": struct(
+                build_content = "filegroup(\n    name = \"foo\",\n    srcs = [\"all\"],\n)",
+                copy_executables = {},
+                copy_files = {},
+                data = [],
+                data_exclude_glob = [],
+                srcs_exclude_glob = [],
+            ),
+        },
+    })
 
 _tests.append(_test_simple_with_whl_mods)