boost-factory-fx

REQUIRED BACKGROUND: boost-start, boost-fx-modules (composition patterns), boost-wrapper-log (the logger fx uses).

The factory wraps go.uber.org/fx's fx.New with boost defaults: the app's logger comes from wrapper/log so fx events appear in your structured log stream, and the lifecycle is wired into the boot sequence so OnStart / OnStop hooks run with proper context cancellation.

import (
    "go.uber.org/fx"
    fxfact "github.com/xgodev/boost/factory/contrib/go.uber.org/fx/v1"
)

func main() {
    boost.Start()

    app := fxfact.New(
        myModule.Module(),
        otherModule.Module(),
        fx.Provide(NewService),
        fx.Invoke(registerRoutes),
    )
    app.Run()
}

When to use this vs raw fx.New

Use the factory when you want fx events (provider registration, lifecycle transitions) to flow through wrapper/log instead of fx's own stdout writer. For libraries that ship modules but don't run an app, raw fx.Module(...) is fine.

Fail loud at boot

A constructor in fx.Provide or an fx.Invoke that returns an error makes fx fail the app build and app.Run() exit non-zero — and the surfaced reason can be terse: a config-validation error returned from a provider can read as a bare exit 1 with little context after the logger banner. So validate loudly: in the provider, log the specific failure (which key, which value) before returning the error, and prefer errors.NewInternal(err, "config: <key>=<value>") over a bare error. A silent exit 1 once the logger is up almost always means a provider rejected its config — make sure the provider says which one. (dev-rules LAW 4: fail loud, fail specific.)

Red flags

Red flag	Fix
fx.New(...) directly with fx.WithLogger(fxevent.NopLogger)	fxfact.New(...) so events flow through wrapper/log
A boot provider returns a bare error on bad config → opaque exit 1	Log the specific bad key/value in the provider before returning; wrap with errors.NewInternal(err, "config: <key>=<value>"). A swallowed boot error costs hours to diagnose.
app.Run() before boost.Start()	boost.Start() is always first
Mixing fxfact.New with fx.New in the same binary	Pick one