闭包练习三

counter.js

// function counter(initValue, seed) {}

// testcase
var incrementByOneFromOne = counter(1, 1);
incrementByOneFromOne.should.include.keys('value');
incrementByOneFromOne.should.include.keys('increment');
incrementByOneFromOne.should.include.keys('decrement');

// testcase
var incrementByOneFromOne = counter(1, 1);
incrementByOneFromOne.value().should.equals(1);

// testcase
var incrementByOneFromOne = counter(1, 1);
incrementByOneFromOne.increment().value().should.equals(2);

// testcase
var incrementByOneFromOne = counter(1, 1);
incrementByOneFromOne.decrement().value().should.equals(0);

// testcase
var incrementByTenFromFive = counter(10, 5);
incrementByTenFromFive.value().should.equal(10);
incrementByTenFromFive.increment().value().should.equal(15);
incrementByTenFromFive.decrement().value().should.equal(10);

// testcase
var counter1 = counter(1, 1);
var counter2 = counter1(2, 2);
counter2.value().should.equal(3);

// testcase
var counter1 = counter(1, 1);
var counter2 = counter1(2, 2);
var counter3 = counter2(-1, -1);
counter3.value().should.equal(2);

// testcase
var counter1 = counter(1, 1);
var counter2 = counter1(2, 2);
counter2.increment().value().should.equal(6);

// testcase
var counter1 = counter(1, 1);
var counter2 = counter1(2, 2);
counter2.decrement().value().should.equal(0);