Express API 上的模块共享和动态属性

Question

我是 NodeJS / Express 的新手，我遇到了与全局/模块共享模块和配置设置相关的问题，我将在此处尝试解释。

一个简单的例子是尝试对包含其他库的中间件模块进行单元测试。如下：

config/settings.js

module.exports = {
...,
debugLevel: 3

};

中间件/auth.js

// Required modules for middleware
// ----------------------------------------------------------------------
var config = require('../config/settings');

var log = require('../libraries/logger')('middlewares/auth');
...

// Middleware methods
// ----------------------------------------------------------------------
var middleware = {};

middleware.apicall = function(req, res, next) {
    ...
    log.info('Made api call');
};

库/logger.js

// External Dependencies
var winston = require('winston');
var winlogger =  new (winston.Logger)({
    transports: [
        new (winston.transports.Console)()
    ]
});
winlogger.cli();


var logger = function(module, debug) {
    this.module = module;
    this.logger = winlogger;
    this.debugLevel = debugLevel;
};

logger.prototype = {
    module: '',
    logger: null,
    debugLevel: 3,


    /**
     * Generic Log function
     *
     * @param level
     * @param str
     * @param data
     */
    debug: function(level, str, data) {
        if ( this.debugLevel > 2) this.logger.log(level, this.module+' - '+str, data);
    },

    /**
     * Specific function for info
     *
     * @param str
     * @param data
     */
    info: function(str, data) {
        if ( this.debugLevel > 1 ) this.logger.info(this.module+' - '+str, data);
    }
};

tests/api.js

const chai = require('chai');
const should  = chai.should;
const expect = chai.expect;
const assert = chai.assert;

// Node Http Mocks
var httpMocks = require('node-mocks-http');
var middleware = require('../middlewares/auth');

describe("Test API Call", function() {

    it("should give 200 over api call", function(done) {
        var req = httpMocks.createRequest({
            method: 'GET',
            url: '/test',
            params: {}
        });
        var res = httpMocks.createResponse();
        middleware.apicall(req, res, function(res) { return res; });

        assert.equal(res.statusCode, 200);

        done();
    });

});

现在所有这些都可以了，但我遇到的问题是：如何在不显示 apicall 方法的日志行的情况下进行测试？

有没有办法让设置全局存在？或者一种构建应用程序的方法，以便您可以将来自单个要求的设置注入 app.js ？

我需要在 tests/api.js 中做这样的事情：

var config = require('../config/settings');
config.debug = 0;

并可能将其注入测试。有人遇到过类似的挑战吗？

Answer 1

回答

在没有找到解决方案的情况下，我尝试进行了一系列测试并想出了一个可行的解决方案。

对于这种特殊情况，我们使用全局变量。所以：

bin\www

#!/usr/bin/env node

/**
 * Module dependencies.
 */
var app = require('../app');
...
var http = require('http');

global.config = require('../config/settings');
global.log = require('../libraries/logger')('server');

...

app.js

// Node framework dependencies
// ----------------------------------------------------------------------
var express = require('express');
var config = global.config;
var path = require('path');
var log = global.log;
log.setLabel('app');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var cors = require('cors');
var validator = require('express-validator');
...

测试\api.js

const chai = require('chai');
const should  = chai.should;
const expect = chai.expect;
const assert = chai.assert;

global.config = require('../config/settings');
config.debug = false;
global.log = require('../libraries/logger')('Test case');

...
// Node Http Mocks
var httpMocks = require('node-mocks-http');
var middleware = require('../middlewares/auth');


describe("Test API Call", function() {
    it("should give 200 over api call", function(done) {
        var req = httpMocks.createRequest({
            method: 'GET',
            url: '/test',
            params: {}
        });
        var res = httpMocks.createResponse();
        middleware.apicall(req, res, function(res) { return res; });
        assert.equal(res.statusCode, 200);
        done();
    });
});