: json-content-type ( -- String )
    "application/json"
;

: form-content-type ( -- String )
    "application/x-www-form-urlencoded"
;

: make-json-body ( String Int -- String )
    # ( name age -- json )
    int->string
    swap
    "{\"name\":\"" swap string.concat
    "\",\"age\":" string.concat
    swap string.concat
    "}" string.concat
;

: test-post ( -- )
    json-content-type
    "application/json" test.assert-eq

    form-content-type
    "application/x-www-form-urlencoded" test.assert-eq

    "Alice" 30 make-json-body
    "{\"name\":\"Alice\",\"age\":30}" test.assert-eq

    "Bob" 25 make-json-body
    "{\"name\":\"Bob\",\"age\":25}" test.assert-eq
;
