[mazkev]

Summary

1. Clean []map[any]any slices before JSON encoding:

   • cleanUp(v any) previously supported []any, []map[string]any, []Map, and map[any]any, but omitted []map[any]any (slices of interface maps commonly produced by YAML unmarshalers or dynamic data).
   • Because concrete slice types do not match []any in Go type switches, []map[any]any fell through to default: return v, resulting in json: unsupported type: map[interface {}]interface {} when calling JSON() or Base64().
   • Added cleanUpInterfaceMapArray(in []map[any]any) []Map and registered case []map[any]any: in cleanUp.

2. Add URLValuesSliceKeySuffix getter:

   • The doc comment in conversions.go previously referenced an exported URLValuesSliceKeySuffix variable, which was replaced by an unexported variable and SetURLValuesSliceKeySuffix(s string).
   • Added URLValuesSliceKeySuffix() string to allow callers and tests to inspect and safely restore previous suffixes without hardcoding default constants.

3. Tests:

   • Added unit test cases for nil, empty, and populated []map[any]any in conversions_nil_test.go and conversions_test.go.
   • Tested URLValuesSliceKeySuffix() getter alongside SetURLValuesSliceKeySuffix.
   • Verified that all unit tests pass (go test -v ./...).

[hanzei]

Thanks!

Can you please explain why URLValuesSliceKeySuffix needs to be exported? What value does it add for callers?

[mazkev]

Hi @hanzei, thanks for the review!

The motivation for adding the URLValuesSliceKeySuffix() getter was twofold:

1. Safe configuration restore / inspection: Since SetURLValuesSliceKeySuffix mutates package-level global state, callers (and tests) currently have no way to inspect the active suffix or temporarily change it and restore the previous state without hardcoding the default constant (e.g. defer SetURLValuesSliceKeySuffix(URLValuesSliceKeySuffix())).
2. Documentation alignment: The doc comment on lines 17-23 historically referenced URLValuesSliceKeySuffix, which was formerly an exported variable before being made private with a setter.

That being said, if you prefer keeping the public API surface minimal and not exposing the getter, I am more than happy to remove URLValuesSliceKeySuffix() from this PR and keep only the []map[any]any slice cleanup fix!

Let me know what you prefer and I can update the branch accordingly.

[hanzei]

Thanks for the context. you're right that it was exported briefly in 2018 another PR made it private, so the comment has just been stale since then. That said, I'd prefer to keep the API surface as is: callers that change the suffix already know what they set it to, and save/restore is mostly a test concern. Please drop the URLValuesSliceKeySuffix() getter and the test changes, but keep the doc comment rename. The []map[any]any fix looks good and we can merge once that's done.