boost-extra-middleware

REQUIRED BACKGROUND:

• boost-bootstrap-middleware — the middlewares this skill composes.
• boost-bootstrap-adapter-pubsub — the canonical reason this skill is reached for (production workaround).

What it is

extra/middleware.NewAnyErrorWrapper[T](ctx, name, ...mws) is the generic chain composer. It returns a wrapper that you can apply to any handler typed compatibly. fn.Run uses it internally; you reach for it directly only when you can't use fn.Run (e.g., the documented Pub/Sub adapter workaround).

Usage

import (
    "github.com/xgodev/boost/extra/middleware"
    "github.com/xgodev/boost/bootstrap/function"
)

wrp := middleware.NewAnyErrorWrapper[*cloudevents.Event](
    ctx, "bootstrap", rec, lmi, pmi,
)

wrappedHandler := function.Wrapper[*cloudevents.Event](wrp, handle)

// then drive wrappedHandler manually (e.g., apubsub.NewSubscriber)

The middleware order arguments here mirror the order semantics from boost-bootstrap-middleware: outermost-to-innermost is rec, lmi, pmi.

When to use

• The Pub/Sub / NATS / Kafka adapter workaround for ctx-loss (see boost-bootstrap-adapter-pubsub).
• Custom drivers / adapters where you need the same chain semantics outside fn.Run.

Don't use when the canonical function.New + fn.Run works — fn.Run already calls this internally with the right arguments.

Red flags

Red flag	Fix
Used in place of fn.Run without a // TODO(boost-upstream): comment explaining why	Either add the comment + tracking issue, or use fn.Run
Different T parameter than the rest of the chain	All on *cloudevents.Event
Custom middleware order that breaks the recovery-outermost rule	Mirror boost-bootstrap-middleware's canonical order