def submodule_ref()

in src/buildstream_plugins/sources/git.py [0:0]

• 28 lines of code
• 6 McCabe index (conditional complexity)

    def submodule_ref(self, submodule, ref=None):
        if not ref:
            ref = self.ref

        # list objects in the parent repo tree to find the commit
        # object that corresponds to the submodule
        _, output = self.source.check_output(
            [self.source.host_git, "ls-tree", ref, submodule],
            fail="ls-tree failed for commit {} and submodule: {}".format(ref, submodule),
            cwd=self.mirror,
        )

        # read the commit hash from the output
        fields = output.split()
        if len(fields) >= 2 and fields[1] == "commit":
            submodule_commit = output.split()[2]

            # fail if the commit hash is invalid
            if len(submodule_commit) != 40:
                raise SourceError(
                    "{}: Error reading commit information for submodule '{}'".format(self.source, submodule)
                )

            return submodule_commit

        else:
            detail = (
                "The submodule '{}' is defined either in the BuildStream source\n".format(submodule)
                + "definition, or in a .gitmodules file. But the submodule was never added to the\n"
                + "underlying git repository with `git submodule add`."
            )

            self.source.warn(
                "{}: Ignoring inconsistent submodule '{}'".format(self.source, submodule),
                detail=detail,
                warning_token=WARN_INCONSISTENT_SUBMODULE,
            )

            return None