Racket dynamic reload

beta.rkt

#lang racket/base

(provide beta)

(require "alpha.rkt")

(define beta alpha)

racket-dynamic-reload.rkt

#lang racket/base

(require racket/rerequire)
(module+ test (require rackunit))
(require rackunit)

(define (get-beta)
  (dynamic-rerequire "beta.rkt")
  (dynamic-require "beta.rkt" 'beta))

(define (set-alpha! v)
  (with-output-to-file "alpha.rkt" #:exists 'replace
    (lambda ()
      (printf "#lang racket/base\n(provide alpha)\n(define alpha ~v)\n" v))))

(module+ test
  (set-alpha! 1)
  (check-eqv? (get-beta) 1)
  
  (set-alpha! 2)
  (check-eqv? (get-beta) 2)

  (set-alpha! 5)
  (check-eqv? (get-beta) 5))