在调研了几个库之后，我选用了 coffee-coverage 和 mocha 这个两个库。

"devDependencies": {
  "mocha": "^1.21.5",
  "chai": "^1.9.2",
  "coffee-coverage": "^0.4.2"
}

在 test/support/env.coffee 引入 coffee-coverage:

if process.env.COV_TEST == 'true'
  require('coffee-coverage').register
    path: 'relative'
    basePath: "#{__dirname}/../.."
    exclude: ['test', 'node_modules', '.git', 'sample', 'static']
    initAll: true

coffee-coverage 的文档上写的 exlude 示例是 exclude: ['/test', '/node_modules', '/.git'], 但我在被坑了一个半小时之后才发现前面不能加斜杠…
我发了个 Pull Request, 目前还没被处理。

在 test/app.coffee 里写第一个测试，

describe 'app', ->
  it 'should can startup', ->
    # 在我的机器上启动需要差不多 15 秒时间.....
    @timeout 20000 
    require '../../app'

mocha 默认的测试报告只会显示测试的通过情况，不会显示测试覆盖率，因此我们要拓展一下 mocha 默认的测试报告，在 test/support/reporter-cov-summary.js,

var fs = require('fs');
var util = require ('util');
var Spec = require('mocha/lib/reporters/spec');

exports = module.exports = CovSummary;

function CovSummary(runner) {
  Spec.call(this, runner);
  runner.on('end', report);
}

function report() {
  var cov = global._$jscoverage || {};
  var files = Object.keys(cov);

  var covered_lines = 0;
  var total_lines = 0;

  files.forEach(function(file) {
    cov[file].forEach(function(line) {
      if(line !== undefined) {
        total_lines ++;

        if (line !== 0) {
          covered_lines ++;
        }
      }
    });
  });

  var covered = (covered_lines / total_lines * 100).toFixed(1);
  console.log(util.format('Coverage Summary: %s lines of %s lines, %s% covered \n', covered_lines, total_lines, covered));
}

CovSummary.prototype.__proto__ = Spec.prototype;

这个文件是用 JavaScript 写的，我实在没搞清楚 mocha 怎么直接用 Coffee 的测试报告；它会在测试运行结束后输出一个覆盖率概要，类似于：

Coverage Summary: 305 lines of 2056 lines, 14.8% covered

在 package.json 中加上 scripts:

"scripts": {
  "start": "./node_modules/.bin/coffee app.coffee",
  "test": "COV_TEST=true ./node_modules/.bin/mocha --compilers coffee:coffee-script/register --require test/support/env --reporter test/support/reporter-cov-summary.js -- test",
  "test-only": "./node_modules/.bin/mocha --compilers coffee:coffee-script/register --require test/support/env -- test",
  "test-cov-html": "COV_TEST=true ./node_modules/.bin/mocha --compilers coffee:coffee-script/register --require test/support/env --reporter html-cov -- test > coverage-reporter.html"
},

start 是启动应用，test 是运行测试和覆盖率报告，test-only 只运行测试，test-cov-html 会生成 HTML 格式的测试覆盖率报告。

然后还要改一下 .gitinore, 加上 /coverage-reporter.html.

最后是 .travis.yaml,

language: node_js

node_js:
  - "0.10"

差不多就是这样。

https://jysperm.me/technology/1909