Function refresh_suppressed_submodules

mypy/server/update.py:1232–1307

Look for submodules that are now suppressed in target package. If a submodule a.b gets added, we need to mark it as suppressed in modules that contain "from a import b". Previously we assumed that 'a.b' is not a module but a regular name. This is only relevant when following import

(
    module: str,
    path: str | None,
    deps: dict[str, set[str]],
    graph: Graph,
    fscache: FileSystemCache,
    refresh_file: Callable[[str, str], list[str]],
)

def refresh_suppressed_submodules(
    module: str,
    path: str | None,
    deps: dict[str, set[str]],
    graph: Graph,
    fscache: FileSystemCache,
    refresh_file: Callable[[str, str], list[str]],
) -> list[str] | None:
    """Look for submodules that are now suppressed in target package.

    If a submodule a.b gets added, we need to mark it as suppressed
    in modules that contain "from a import b". Previously we assumed
    that 'a.b' is not a module but a regular name.

    This is only relevant when following imports normally.

    Args:
        module: target package in which to look for submodules
        path: path of the module
        refresh_file: function that reads the AST of a module (returns error messages)

    Return a list of errors from refresh_file() if it was called. If the
    return value is None, we didn't call refresh_file().
    """
    messages = None
    if path is None or not path.endswith(INIT_SUFFIXES):
        # Only packages have submodules.
        return None
    # Find any submodules present in the directory.
    pkgdir = os.path.dirname(path)
    try:
        entries = fscache.listdir(pkgdir)
    except FileNotFoundError:
        entries = []
    for fnam in entries:
        if (
            not fnam.endswith((".py", ".pyi"))
            or fnam.startswith("__init__.")
            or fnam.count(".") != 1
        ):
            continue
        shortname = fnam.split(".")[0]
        submodule = module + "." + shortname
        trigger = make_trigger(submodule)

        # We may be missing the required fine-grained deps.
        ensure_deps_loaded(module, deps, graph)

        if trigger in deps:
            for dep in deps[trigger]:
                # We can ignore <...> deps since a submodule can't trigger any.
                state = graph.get(dep)
                if not state:
                    # Maybe it's a non-top-level target. We only care about the module.
                    dep_module = module_prefix(graph, dep)
                    if dep_module is not None:
                        state = graph.get(dep_module)
                if state: