test.pact

(enforce-pact-version "2.3")

(define-keyset 'central-bank-admin-keyset
  (read-keyset "central-bank-admin-keyset"))

(module central-bank-module 'central-bank-admin-keyset
  "central bank"

  (defschema central-bank-schema
    ("central bank"
      (invariants
        [ (= 1000000 (+ reserve circulation))
          (>= reserve 0)
          (>= circulation 0)
        ]))
    reserve:integer
    circulation:integer)
  (deftable central-bank-table:{central-bank-schema})

  (defun issue (amt:integer)
    "Issue some amount of currency"

    (let*
      ((before (read central-bank-table "singleton"))
       (new-reserve (- (at 'reserve before) amt))
       (new-circulation (+ (at 'circulation before) amt))
      )

      (enforce (> amt 0) "")
      (enforce (>= new-reserve 0) "")

      (update central-bank-table "singleton" {
        'reserve: new-reserve,
        'circulation: new-circulation
      }))
    ))

test.repl

(env-keys ["centralbankadmin" "user123" "user456"])
(env-data { "central-bank-admin-keyset": ["centralbankadmin"] })
(begin-tx)
(load "test.pact")
(commit-tx)
(verify 'central-bank-module)