[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, e.g. from typed fields filled by YAML decoders or from dynamically built 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. Fix stale doc comment:

   • The doc comment on the unexported urlValuesSliceKeySuffix variable still used its old exported name, URLValuesSliceKeySuffix, from before it was made private in URLQuery with index slice keys #74.

3. Tests:

   • Added unit test cases for nil, empty, and populated []map[any]any in conversions_nil_test.go, and a nested case in TestConversionJSON in conversions_test.go.
   • 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.

[mazkev]

Thanks @hanzei! I've dropped the URLValuesSliceKeySuffix() getter and reverted the corresponding test changes while keeping the doc comment fix and the []map[any]any slice cleanup with its tests.

Branch is updated and ready for merge!