MattMcFarland

const jsc = require('jsverify')
const Chance = require('chance')
const chance = new Chance()
chance.mixin({
  user: () => ({
    first: chance.first(),
    last: chance.last(),
    email: chance.email()
  })            
})

MattMcFarland

const Chance = require('chance')
const chance = new Chance()
chance.mixin({
  user: () => ({
    first: chance.first(),
    last: chance.last(),
    email: chance.email()
  })            
});
console.log('here is a random user!', chance.user())

MattMcFarland

jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a)
// is the same as
jsc.check(jsc.forall(jsc.integer, jsc.integer, (a, b) => a + b === b + a))

MattMcFarland

const options = {
  tests: 5, // test count to run, default 100
  size: 50, // maximum size of generated values, default 50
  quiet: false, // do not console.log if true
  rngState: '074e9b5f037a8c21d6', // state string for the rng
}

MattMcFarland

test('addition is commutative', (t) => {
  t.plan(1)   
  t.equal(jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a), true)    
})

MattMcFarland

describe('Maths', () => {
  it('addition is commutative', () => {
    expect(jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a)).toBeTrue()
  })
})

MattMcFarland

// using should:
jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a).should.be.true
// using expect:
expect(jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a)).to.be.true

MattMcFarland

describe('Maths', () => {
  it('addition is commutative', () => {
   jsc.assertForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a)
   // same as: 
   assert(jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a) === true)
  })
})

MattMcFarland

// node assertion library
assert(jsc.checkForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a) === true)
// same as:
jsc.assertForall(jsc.integer, jsc.integer, (a, b) => a + b === b + a)

MattMcFarland

const jsc = require('jsverify')
// With property based testing, we don't check for specific inputs and outputs, instead we are testing the boundaries of our code.
const additionIsCommutative = jsc.checkForall(jsc.integer, jsc.integer, 
  (a, b) => a + b === b + a)
const multiplicationIsDistributive = jsc.checkForall(jsc.integer, jsc.integer, jsc.integer, 
  (a, b, c) => a * (b + c) === a * b + a * c)
// log out whether or not the test passed
console.log({ additionIsCommutative, multiplicationIsDistributive })