请考虑以下几点:
注意:下面显示的示例只是为了简洁起见,没有考虑实际的用例
文件:simpleCalcs.js
module.exports = function () {
return {
sum: (listOfNumbers) => {
console.log('inside test2 sum()');
return listOfNumbers.reduce((a, b) => a + b, 0);
}
}
};
文件:mediumCalcs.js
const simpleCalcs = require('./simpleCalcs')();
module.exports = function () {
return {
avg: (listOfNumbers) => {
console.log('inside test1 avg()')
return simpleCalcs.sum(listOfNumbers) / listOfNumbers.length;
}
}
};
文件:mediumCalcs.test.js
const sinon = require('sinon');
const expect = require('chai').expect;
const simpleCalcs = require('./simpleCalcs')();
const mediumCalcs = require('./mediumCalcs')();
describe('sample test', () => {
before(() => {
summationStub = sinon.stub(simpleCalcs, 'sum').returns(3);
});
it('average', () => {
const result = mediumCalcs.avg([1, 2, 3]);
expect(result).to.be.equal(1);
});
});
此测试失败,因为未调用存根函数。
如何确保在存根时会照顾到module.exports = function () {....}
?
sinon是否能够满足此类要求?
P.S使用module.exports = function () {....}
而不是module.exports = {....}
的原因是因为可以通过参数注入某些依赖项。
例如
simpleCalcs.js
:
module.exports = function() {
return {
sum: (listOfNumbers) => {
console.log('inside test2 sum()');
return listOfNumbers.reduce((a, b) => a + b, 0);
},
};
};
mediumCalcs.js
:
const simpleCalcs = require('./simpleCalcs')(); module.exports = function() { return { avg: (listOfNumbers) => { console.log('inside test1 avg()'); return simpleCalcs.sum(listOfNumbers) / listOfNumbers.length; }, }; };
mediumCalcs.test.js
:
const sinon = require('sinon'); const expect = require('chai').expect; const proxyquire = require('proxyquire'); describe('sample test', () => { it('average', () => { const simpleCalcsStub = { sum: sinon.stub().returns(3), }; const simpleCalcs = sinon.stub().callsFake(() => simpleCalcsStub); const mediumCalcs = proxyquire('./mediumCalcs.js', { './simpleCalcs': simpleCalcs, })(); const result = mediumCalcs.avg([1, 2, 3]); expect(result).to.be.equal(1); sinon.assert.calledOnce(simpleCalcs); sinon.assert.calledWithExactly(simpleCalcsStub.sum, [1, 2, 3]); }); });
带有覆盖率报告的单元测试结果:
sample test inside test1 avg() ✓ average (1613ms) 1 passing (2s) ----------------|---------|----------|---------|---------|------------------- File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s ----------------|---------|----------|---------|---------|------------------- All files | 60 | 100 | 40 | 66.67 | mediumCalcs.js | 100 | 100 | 100 | 100 | simpleCalcs.js | 20 | 100 | 0 | 25 | 2,4,5 ----------------|---------|----------|---------|---------|-------------------
源代码:https://github.com/mrdulin/expressjs-research/tree/master/src/stackoverflow/60746613