fix(rivetkit): preserve bridge error messages

[NathanFlurry]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[claude]

PR 4959 Review: fix(rivetkit): preserve bridge error messages

Overview

This PR fixes a bug where error messages were lost when bridging RivetErrors across the NAPI/WASM boundary. The root cause: BridgeRivetErrorContext Display was showing internal debug metadata (public, status_code) instead of the actual error message. Since anyhow Error to_string() renders only the outermost context Display, the human-readable message was invisible at the top level.

The fix adds a message field to BridgeRivetErrorContext and routes the actual error text through it.

What is correct

• Root cause and fix are right. anyhow to_string() renders only the outermost context. Storing the message in the context struct and forwarding it through Display is the correct pattern.
• Both runtimes updated consistently. actor_factory.rs (NAPI) and rivetkit-wasm/src/lib.rs (WASM) receive identical changes, maintaining parity.
• actor_context.rs capture order is correct. error.to_string() is evaluated before error is moved into .context(...), so the message is captured from the original error chain.
• Tests added for both paths. assert_eq!(first.to_string(), ...) in the NAPI test and WASM equivalent verify round-trip message preservation through parse_bridge_rivet_error.

Minor observations

1. Option vs String for BridgeRivetErrorContext::message

Both call sites always pass Some(message). payload.message is a non-optional String, and error.to_string() in actor_context.rs always yields a String. The None fallback (bridged RivetError) is dead code today. Making the field String would be more precise and eliminate the dead branch, though Option is a reasonable future-safe default.

2. Message duplication is inherent, not a bug

The message is stored in both RivetError::message (inner anyhow error) and BridgeRivetErrorContext::message (outer context). This is required because anyhow to_string() surfaces only the outermost context. The clone at the parse_bridge_rivet_error call site is the minimal overhead needed.

3. No test for the actor_context.rs verify path

The change in actor_context.rs (capturing error.to_string() before the verify error is consumed) is not covered by a new test. An integration test that triggers a 401 from verify_token and checks the surfaced error message would close this gap. Not a blocker.

4. Pre-existing duplication between NAPI and WASM

BridgeRivetErrorContext is defined independently in actor_factory.rs and rivetkit-wasm/src/lib.rs. This PR correctly keeps both in sync, but a shared crate would eliminate future drift risk.

Summary

The fix is correct, targeted, and well-tested for its primary paths. No blocking issues. All observations above are minor or pre-existing.

[NathanFlurry]

• fix(pegboard): align drain grace defaults with stop threshold #4958 : 2 dependent PRs (#4960 , #4966 )
• fix(rivetkit): preserve bridge error messages #4959 👈 (View in Graphite)
• fix(rivetkit): fire abort signal on shutdown finalize #4957
• fix(rivetkit): use startup kv preload #4956
• fix(client): flatten skipReadyWait option #4955
• ci(publish): add manual preview publish flow #4954
• fix(depot): add ltx decode diagnostics #4953
• fix(universaldb): preserve plain set values #4952
• fix(universaldb): align versionstamp operand encoding #4951
• fix(rivetkit): export database provider types #4950
• wip: kitchen sink agentic loop finish #4949
• chore(rivetkit): note duplicate admission logic #4948
• test(rivetkit): cover bypass fetch header forwarding #4947
• feat(kitchen-sink): add actor probe controls #4946
• fix(gateway): split actor response wait errors #4945
• fix(guard): handle bypass preflight before query parse #4944
• feat(kitchen-sink): add mock agent event log copy #4943
• fix(kitchen-sink): default mock agent to local endpoint #4942
• test(rivetkit): enable driver lifecycle regressions #4941
• test(rivetkit): verify cached websocket db refs exceed grace #4940
• fix(rivetkit-core): keep sleeping actors reachable during grace #4939
• test(rivetkit): cover async websocket close db access #4938
• fix(rivetkit): keep actors awake until keepAwake work finishes #4937
• fix(rivetkit): persist native onSleep state on errors #4936
• fix(rivetkit-core): allow dispatch during sleep grace #4935
• fix(rivetkit): make duplicate sleep requests idempotent #4934
• main

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