tools/go/mirror_lib.py

"""Provides helper functions for mirroring Go repositories."""

import unittest.mock
from typing import List, Dict


def read_file(filepath: str) -> str:
    """Reads an entire file by returning its contents as a string."""
    with open(filepath, "r") as file:
        return file.read()

def parse_go_repositories(filepath: str) -> List[Dict[str, str]]:
    """Parses the top-level go_deps.bzl file.

    This function can parse both the original version of the file generated by
    gazelle as well as the tweaked version generated by
    tweak_gazelle_go_deps.py. The two versions are identical other than what function they call.
    """
    global_functions = {
        "load": unittest.mock.MagicMock(),
        # The gazelle generated version uses go_repository().
        "go_repository": unittest.mock.MagicMock(),
        # The tweak_gazelle_go_deps.py generated version uses
        # maybe_override_go_dep().
        "maybe_override_go_dep": unittest.mock.MagicMock()
    }
    compiled_code = compile(read_file(filepath), filepath, "exec")
    eval(compiled_code, global_functions)

    # Extract the repositories defined in the go_dependencies() function from
    # go_deps.bzl.
    global_functions["go_dependencies"]()

    repositories = []
    for repo_kind in ("go_repository", "maybe_override_go_dep"):
        for repo in global_functions[repo_kind].mock_calls:
            _, _, kwargs = repo
            repositories.append(kwargs)

    return repositories