Improve event outcome handling

[fhanau]

This includes a number of smaller changes to provide better event outcome handling and more closely correspond to the edge runtime behavior.

• In server.c++, report proxyDisconnect and memoryExceeded outcomes properly. This should cover all outcomes that can be reported using exceptions in workerd so far
• Return a 503 error for overloaded-type exceptions – matches what we already do in WorkerEntrypoint::request()
• Add a missing exception detail to ensure actor-cache exception leads to memoryExceeded outcome
• Simplify reportFailure() calls based on FailureSource::OTHER being the default value for the 2nd parameter

Also see the downstream PR

[ask-bonk]

I'm Bonk, and I've done a quick review of your PR.

This PR improves event outcome reporting by mapping exception types to appropriate EventOutcome values and returning 503 for overloaded exceptions.

Issues found (ranked by severity):

1. Build-breaking: wrong variable name e vs exception — reportFailure() names the parameter exception but the body uses e. Same issue in the request() catch block. This won't compile.
2. Build-breaking: RequestOutcome does not exist — The code uses RequestOutcome::PROXY_DISCONNECT and RequestOutcome::EXCEPTION, but the type is EventOutcome. There is no RequestOutcome in the codebase.
3. Build-breaking: EventOutcome::MEMORY_LIMIT_EXCEEDED does not exist — The correct enum value is EventOutcome::EXCEEDED_MEMORY (see outcome.capnp and existing usage in the codebase). Similarly, there is no PROXY_DISCONNECT; the closest match is EventOutcome::RESPONSE_STREAM_DISCONNECTED.

[ask-bonk]

I'm Bonk, and I've done a quick review of your PR.

This PR improves event outcome reporting by mapping exception types to appropriate EventOutcome values and returning 503 for overloaded exceptions.

3 build-breaking issues found (all in src/workerd/server/server.c++):

1. Wrong variable name e vs exception — reportFailure() names its parameter exception but the body references e in three places (lines 1608, 1611, 1635). This won't compile.

2. RequestOutcome does not exist — Lines 1612 and 1614 use RequestOutcome::PROXY_DISCONNECT and RequestOutcome::EXCEPTION, but the actual type is EventOutcome. There is no RequestOutcome anywhere in the codebase.

3. EventOutcome::MEMORY_LIMIT_EXCEEDED does not exist — Line 1609 uses this value, but the correct enum member is EventOutcome::EXCEEDED_MEMORY (per outcome.capnp). Similarly, PROXY_DISCONNECT is not a member; the closest match is RESPONSE_STREAM_DISCONNECTED.

Suggestions with fixes have been posted inline on the PR.

github run

[github-actions]

The generated output of @cloudflare/workers-types matches the snapshot in types/generated-snapshot 🎉