gather_metadata doesn't transitively handle the label_keyed_string_dict_type

[quic-sbjorkle]

Expected Behavior

When generating a transitive metadata list using the @rules_license//rules_gathering:gather_metadata.bzl%gather_metadata_info_and_write aspect we expect all metadata for the complete dependency tree to be collected.

Actual Behavior

Dependency tree is cut when reaching an attribute with the label_keyed_string_dict_type.

Steps to Reproduce the Problem

1. Declare a rule with an attribute with type label_keyed_string_dict_type
2. Instantiate the rule and add dependencies to a licensed target on the dict -> string format
3. Execute the aspect and notice how the license information is lost in the aggregation

Proposed solution

Extend label_keyed_string_dict_type in licenses_core.bzl to also expand the dict keys.

Example:

        dict_deps = []
        for dep in a:
            if type(dep) == 'dict':
                for d in dep.keys():
                    if type(d) != 'list':
                        dict_deps.append(d)
                    else:
                        dict_deps.extend(d)
        for dep in a + dict_deps:
            # Ignore anything that isn't a target
            if type(dep) != "Target":
                continue

Specifications

• Version: 1.0.0
• Platform: linux