npm install @segment/spyTest spy.
``sh`
$ npm install @segment/spy
Create a spy with optional obj, method.
Examples:
`js`
var s = spy();
var s = spy(console, 'log');
var s = spy(spy);
#### args[]
An array that holds all arguments.
Examples:
`js
spy(1, 2, 3);
spy(4, 5, 6);
spy.args[0]; // => [1, 2, 3]
spy.args[1]; // => [4, 5, 6]
`
#### returns[]
An array that holds all returned values.
Examples:
`js
spy = require('spy')(window.btoa);
spy('test');
spy('foo');
s.returns[0]; // => "dGVzdA=="
s.returns[1]; // => "Zm9v"
`
#### .once(), .calledOnce
true if the spy was called only once.
Examples:
`js
spy();
spy.once(); // => true
spy.calledOnce; // => true
spy();
spy.once(); // => false
spy.calledOnce; // => false
`
#### .twice(), .calledTwice
true if called twice.
#### .thrice(), .calledThrice
true if called thrice.
#### .got(...), .calledWith(...)
true if the spy was called with ...
Examples:
`js
spy(1, 2, 3);
spy.got(1, 2, 3); // => true
spy(4, 5, 6);
spy.got(1, 2, 3); // => false
spy(1, 2, 3);
spy.got(1, 2) // => true
spy(1, 2, 3);
spy.got(1) // => true
`
#### .gotExactly(...), .calledWithExactly(...)
true if the spay was called with exactly ...
Examples:
`js
spy(1, 2, 3);
spy.got(1, 2, 3); // => true
spy(4, 5, 6);
spy.got(1, 2, 3); // => false
spy(1, 2, 3);
spy.got(1, 2) // => false
spy(1, 2, 3);
spy.got(1) // => false
`
#### .returned(...)
true if the spy was called with ...
Examples:
`js
spy = spy(window.btoa);
spy('test');
spy.returned('dGVzdA=='); // => true
``