repair-rpc-regression

Repair a JSON-RPC regression

Input: an observed bug with actual and expected wire values, optionally the method name and the protocol/reference behavior.

This lane repairs a regression; it does not add unrelated methods or refactor a namespace. Work in this order:

1. Locate the nearest public boundary that reproduces the report: the JSON-RPC dispatcher, HTTP/WebSocket/IPC server, or memory client. Trace inward through the response type, native engine request, and conversion helper. Read the equivalent neighboring method before editing.
2. Write the smallest focused test first and run it against the unmodified implementation. Record that it fails for the reported reason. Use real createTevmNode()/createMemoryClient() objects and recorded RPC fixtures; do not mock TEVM objects.
3. Pin the expected behavior to the supplied reference. If no reference was supplied, use a repository conformance fixture or an established neighboring method. If those disagree or do not define the edge case, stop and report the ambiguity rather than inventing Ethereum semantics.
4. Make the minimum implementation change. Review the complete contract matrix for this method even when only one conversion changes: request/params type, result/response type, handler, procedure, namespace unions, native dispatch table, memory-client exposure, named barrels, and tevm facade.
5. Assert the wire shape exactly and prove JSON.stringify(response) succeeds. JSON-RPC outputs contain no Promise, bigint, typed array, Error, or undefined. Quantities use minimal hex; byte data is even-length; fixed storage words are 32-byte left-padded; spec-nullable fields are null.
6. Cover the report's alternate/negative branch: null and error provider responses, short and full-width encodings, legacy transaction fields, missing transport, manual mining, or state transitions as applicable. Assert the stable error class and JSON-RPC numeric code. Do not share mutable clients, Common instances, caches, or timers between test cases.
7. Correct JSDoc and guide text only where the repaired public contract was wrong. Examples are executable, fully imported, and type-valid.
8. Add a patch changeset naming every published package whose runtime behavior changed. Run all declared gates and keep the diff focused on this method.

Do not update snapshots until the focused semantic assertions pass. Never turn an unexpected error snapshot into the new expected behavior merely to make the suite green.

Execution and state belong to sibling ZEVM, Voltaire, and Guillotine Mini repositories. This action may fix TEVM host adapters. If the regression requires a native patch, identify the owning files and required regression in the result; do not recreate a JavaScript engine or edit outside the candidate write set.