gistfile1.js

'use strict';

var c = require('rho-contracts')

var Mongoose = {
    puts1: function(text) {
        console.log(text)
    }
}

var mongoose = Object.create(Mongoose)

mongoose.puts2 = function(text) {
    console.log(text)
}

var run = function(mongoose) {
    // both should fail
    mongoose.puts1(1)
    mongoose.puts2(2)
}

var runContract = c.fun({
        mongoose: c.object({
            puts1: c.fun({
                text: c.string
            }),
            puts2: c.fun({
                text: c.string
            }),
        })
    })

run = runContract.wrap(run)

run(mongoose)