swagger工具错误处理程序中间件不捕获错误

Question

概述

我的自定义errorHandler中间件没有捕获swagger请求验证器错误。相反，swagger工具HTML错误被发送回客户端。我怎样才能让我的errorHandler中间件捕获工具验证错误并相应地响应客户端呢？

我的预后

不幸的是我很无知。无论我将app.use( errorHandler )指令放在哪里，swagger tools html错误都会返回给客户端，并且我的errorHandler函数永远不会捕获错误。

也许我忽略了一些明显不正确的设置。下面是我的app.js文件，app.js下面是不想要的swagger工具HTML错误响应，返回给客户端。同样，我尝试将app.use(errorHandler)按字面意思(象征性地)放在任何地方，尽管下面的代码只显示在两个地方。

app.js

"use strict";

var swaggerTools = require("swagger-tools");
var compression = require("compression");
var app = require("express")();
var logger = require("./config/logger");
var projectConfig = require("./config/projectConfig");
var debug = require("debug")("app-js"); // run this to enable debug logging DEBUG=app-js node app.js

// swaggerRouter configuration
var options = {
    controllers: './api/controllers',
    useStubs: false
};

// The Swagger document (require it, build it programmatically, fetch it from a URL, ...)
var swaggerDoc = require('./api/swagger/swagger.json');

// compress all requests except those which have Cache-Control header with the no-transform directive
app.use(compression());

// for testing
module.exports = app;

// global error handler
function errorHandler(err, req, res, next, statusCode) {
    logger.error(err);
    debug(err);
    if (res.headersSent) {
        return next(err);
    } else {
        res.status(statusCode || 500).json(projectConfig.genericErrorResponse(statusCode || 500, err.message || err || "something blew up and the err object was undefined"));
    }
}

// handles timed out requests
function haltOnTimedout(req, res, next) {
    if (!req.timedout) {
        next();
    } else {
        debug("\nrequest timed out!\n");
        next("the request timed out", null, null, null, 504);
    }
}

// Initialize the Swagger middleware
swaggerTools.initializeMiddleware(swaggerDoc, function (middleware) {
    "use strict"

    // Interpret Swagger resources and attach metadata to request - must be first in swagger-tools middleware chain
    app.use(middleware.swaggerMetadata());

    app.use(function (req, res, next) {
        res.header("Access-Control-Allow-Origin", "*"); // CORS should be parametrized by configuration
        res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        next();
    });

    // Validate Swagger requests
    // app.use(middleware.swaggerValidator());

    app.use(middleware.swaggerValidator({
        validateResponse: false
    }));

    app.use(haltOnTimedout);
    app.use(errorHandler);

    // Route validated requests to appropriate controller
    app.use(middleware.swaggerRouter(options));
});

app.use(haltOnTimedout);
app.use(errorHandler);

app.listen(projectConfig.port || process.env.PORT || 9000)
    .on("connection", function (socket) {
        debug("\na new cxn was made by a client.\n");
        socket.setTimeout(projectConfig.expressTimeout || 120000);
    })

将swagger工具html错误返回给客户端

Error: Parameter (copy) failed schema validation
<br> &nbsp; &nbsp;at throwErrorWithCode (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/swagger-tools/lib/validators.js:121:13)
<br> &nbsp; &nbsp;at Object.module.exports.validateAgainstSchema (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/swagger-tools/lib/validators.js:176:7)
<br> &nbsp; &nbsp;at /Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/swagger-tools/middleware/swagger-validator.js:143:22
<br> &nbsp; &nbsp;at /Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/async/lib/async.js:356:13
<br> &nbsp; &nbsp;at async.forEachOf.async.eachOf (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/async/lib/async.js:233:13)
<br> &nbsp; &nbsp;at _asyncMap (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/async/lib/async.js:355:9)
<br> &nbsp; &nbsp;at Object.map (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/async/lib/async.js:337:20)
<br> &nbsp; &nbsp;at validateValue (/Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/swagger-tools/middleware/swagger-validator.js:136:11)
<br> &nbsp; &nbsp;at /Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/swagger-tools/middleware/swagger-validator.js:343:21
<br> &nbsp; &nbsp;at /Users/cuv/Documents/dev/dev-project/dev-simple/node_modules/async/lib/async.js:356:13

我在运行什么版本？

节点：

node --version
v6.2.2

最新版本的招摇工具和快递：

"swagger-tools": "^0.10.1",
"express": "^4.12.3"

关

任何帮助和/或洞察如何让我的errorHandler中间件捕获并从而覆盖swagger工具html错误将是非常有必要的。我也把我的问题发布在了apigee社区论坛上，因为它是apigee-127项目的一部分。https://community.apigee.com/questions/29267/swagger-tools-error-handler-middleware-not-catchin.html

谢谢!

Answer 1

我看到了两个问题。

首先:错误处理程序必须有4个args，因此statusCode将被忽略。

errorHandler(err, req, res, next) // correct definition

第二名是

next("the request timed out", null, null, null, 504);

错误句柄的第一个参数必须是错误对象，而不是字符串，因此正确的代码将是

next(new Error("the request timed out")); // other args passed by closure

有许多变体如何通过statusCode。

// 1. Bad way: Pass string with delimiter
next(new Error("the request timed out;404"));
...
// In error handler
var args = err.message.split() // => args[0] = the request timed out, args[1] = 404

// 2. Check message error text
If (err.message == 'the request timed out')  
    statusCode = 404;

// 3. Best way is use custom error

有关自定义错误https://stackoverflow.com/questions/38504780/how-can-i-identify-custom-error/38506930的更多信息