fix: Treat delivery-confirmed proxy errors as delegation success
Two-part fix for issue #159 — successful delegation responses were
rendered as error banners:
PART 1 — a2a_proxy.go: When io.ReadAll fails mid-stream (e.g., TCP
connection drops after the agent sent its 200 OK response), the prior
code returned (0, nil, BadGateway) discarding both the HTTP status code
and any partial body bytes already received. Fix: return
(resp.StatusCode, respBody, error) so callers can inspect what was
delivered even when the body read failed.
PART 2 — delegation.go: New condition in executeDelegation after the
transient-error retry block:
if proxyErr != nil && len(respBody) > 0 && status >= 200 && status < 300 {
goto handleSuccess
}
When proxyA2ARequest returns a delivery-confirmed error (status 2xx +
non-empty partial body), route to success instead of failure. This
prevents the retry-storm pattern where the canvas shows "error" with
a Restart-workspace suggestion even though the delegation actually
completed and the response is available.
Regression tests (delegation_test.go):
- TestExecuteDelegation_DeliveryConfirmedProxyError_TreatsAsSuccess:
server sends 200 + partial body then closes; second attempt succeeds.
Verifies the new condition fires for delivery-confirmed 2xx responses.
- TestExecuteDelegation_ProxyErrorNon2xx_RemainsFailed: server sends
500 + partial body then closes. Verifies non-2xx routes to failure.
- TestExecuteDelegation_ProxyErrorEmptyBody_RemainsFailed: server
returns 502 Bad Gateway (empty body, transient). Verifies empty-body
errors still route to failure (condition len(respBody) > 0 guards it).
- TestExecuteDelegation_CleanProxyResponse_Unchanged: clean 200 OK.
Verifies baseline (proxyErr == nil path) is unaffected.
Fixes issue #159.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Molecule AI Core-BE
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