Work functions

Normally, jobs involve a JobArgs and worker pair. Workers that need only trivial implementations can use WorkFunc to define workers that run functions to work.

Defining a job normally involves a pair of structs — a JobArgs implementation containing job arguments, and a worker struct providing a Work definition. When prototyping, or where a job is involved that requires only a trivial definition, the worker struct can be omitted by wrapping a function with WorkFunc:

type WorkFuncArgs struct {
    Message string `json:"message"`
}

func (WorkFuncArgs) Kind() string { return "work_func" }

...

workers := river.NewWorkers()
river.AddWorker(workers, river.WorkFunc(func(ctx context.Context, j *river.Job[WorkFuncArgs]) error {
    fmt.Printf("Message: %s", j.Args.Message)
    return nil
}))

See the WorkFunc example for complete code.

Worker structs are generally preferable for better organization and testability, but WorkFunc can be handy as a more concise alternative depending on the situation.