(define-syntax-rule (mock (module proc replacement) body ...)
  "Within BODY, replace the definition of PROC from MODULE with the definition
given by REPLACEMENT."
  (let* ((m (resolve-module 'module))
         (original (module-ref m 'proc)))
    (dynamic-wind
      (lambda () (module-set! m 'proc replacement))
      (lambda () body ...)
      (lambda () (module-set! m 'proc original)))))

Generated by apteryx using scpaste at Thu Apr 9 14:54:56 2026. JST. (original)