node.js - 我如何用 mocha 排除常见的 before() 调用？

Question

我的 mocha 测试中有很多重复项:

describe("Some test", function() {
    before(helpers.testPrepare);
    beforeEach(helpers.freshDB);

    it("should foo", function(done) {
        //...
        done();
    });

    after(helpers.teardownServer);
});

describe("Another test", function() {
    before(helpers.testPrepare);
    beforeEach(helpers.freshDB);

    it("should bar", function(done) {
        //...
        done();
    });

    after(helpers.teardownServer);
});

如果我忘记调用 beforeEach ，这可能会导致问题，重构起来会很痛苦。我想定义一个 describe 确保我总是调用我的设置和拆卸，所以我可以写:

我想这样写:

var describe = require('./helpers').describe;

describe("Some test", function() {
    it("should foo", function(done) {
        //...
        done();
    });
});

我该怎么做，因为 mocha 将 describe 定义为全局的？如何确保一切都按正确的顺序执行？

Answer 1

我会创建一个包含以下内容的 helpers.js 文件:

function beforeEachExample() { console.log("before each"); }

function beforeExample() { console.log("before"); }

function afterExample() { console.log("after"); }

function makeSuite(desc, cb) {
    describe(desc, function () {
        before(beforeExample);
        beforeEach(beforeEachExample);

        cb();

        after(afterExample);
    });
}

exports.makeSuite = makeSuite;

然后我可以拥有 test/something.js:

var makeSuite = require("../helpers").makeSuite;

makeSuite("something", function () {
    it("one", function () {});
    it("two", function () {});
});

和test/somethingelse.js:

var makeSuite = require("../helpers").makeSuite;

makeSuite("something else", function () {
    it("one", function () {});
    it("two", function () {});
});

运行上面的设置会得到:

$ mocha

  something
before
before each
    ✓ one 
before each
    ✓ two 
after

  something else
before
before each
    ✓ one 
before each
    ✓ two 
after

  4 passing (5ms)