sinon 学习

[fish519]

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[fish519]

const sinon = require('sinon');

// spies 主要用于收集函数的调用信息
const spy = sinon.spy();
spy('hello', 'world');
console.log(spy.firstCall.args) // [ 'hello', 'world' ]

const user = {
setName: function(name){
this.name = name;
}
}
const setNameSpy = sinon.spy(user, 'setName');
user.setName('fish');
console.log(setNameSpy.callCount); // 1
setNameSpy.restore();

// 使用 stub 的时候原是函数就不会被执行
const stub = sinon.stub();
stub('hello');
console.log(stub.firstCall.args);

// stub 常用场景是验证一个函数是否使用特定的参数
// sinon.assert.calledWith(stubFn, expectedParams);
function saveUser(user, callback) {
$.post('/users', {
first: user.firstname,
last: user.lastname
}, callback);
}

// describe('saveUser', function() {
// it('should send correct parameters to the expected URL', function() {

// //We'll stub $.post same as before
// var post = sinon.stub($, 'post');

// //We'll set up some variables to contain the expected results
// var expectedUrl = '/users';
// var expectedParams = {
// first: 'Expected first name',
// last: 'Expected last name'
// };

// //We can also set up the user we'll save based on the expected data
// var user = {
// firstname: expectedParams.first,
// lastname: expectedParams.last
// }

// saveUser(user, function(){} );
// post.restore();

// sinon.assert.calledWith(post, expectedUrl, expectedParams);
// });
// });

// mock 可以定义期望的结果和期望的行为

// 最佳实践，使用sinon.test()

// spy本质是一个函数wrapper
function createSpy(targetFunc) {
var spy = function() {
spy.args = arguments;
spy.returnValue = targetFunc.apply(this, arguments);
return spy.returnValue;
};
return spy;
}
const sum = (a,b) => a+b;
const syiedSum = createSpy(sum);
syiedSum(10,5)
console.log(syiedSum.args); // [Arguments] { '0': 10, '1': 5 }
console.log(syiedSum.returnValue); // 15

// stub 其实就是替换
const myStub = () => {console.log('stub fun');}
const package = {
$: () => {
console.log('$ fun');
}
}
package.$(); // $ fun
package.$ = myStub;
package.$(); // stub fun

地址： https://blog.kazaff.me/2016/11/11/%E8%AF%91-Sinon%E5%85%A5%E9%97%A8%EF%BC%9A%E5%88%A9%E7%94%A8Mocks%EF%BC%8CSpies%E5%92%8CStubs%E5%AE%8C%E6%88%90javascript%E6%B5%8B%E8%AF%95/#%E8%AF%91%E6%96%87