Fix bug of var m equals null（Hot fix for v1.7.2）

[hori-ryota]

newrelic/lib/instrumentation/shared/connect-express.js:141
if (m.handle !== sentinel) {
^
TypeError: Cannot read property 'handle' of null

[groundwater]

That's no good 😦

I would like to add a test to guard against this fix from happening again. Can you describe your setup that caused the error?

[hori-ryota]

express@4.0.0 or latest.

I start, and it occurs immediately.

Error message is here.

TypeError: Cannot read property 'handle' of null
    at cb_filter (/.../node_modules/newrelic/lib/instrumentation/shared/connect-express.js:135:16)
    at Array.filter (native)
    at Function.cls_wrapMiddlewareStack [as route] (/.../node_modules/newrelic/lib/instrumentation/shared/connect-express.js:128:31)
    at Function.proto.(anonymous function) [as get] (/.../node_modules/express/lib/router/index.js:446:22)

My dependency of package.json is here.

  "dependencies": {
    "async": "0.9.0",
    "basic-auth-connect": "1.0.0",
    "body-parser": "1.3.1",
    "compression": "1.0.7",
    "config": "0.4.36",
    "connect-flash": "0.1.1",
    "cookie-parser": "1.1.0",
    "debug": "1.0.2",
    "ejs": "1.0.0",
    "express": "4.4.3",
    "forever": "0.11.1",
    "lodash": "2.4.1",
    "memory-cache": "0.0.5",
    "mime": "1.2.11",
    "morgan": "1.1.1",
    "newrelic": "1.7.1",
    "passport": "0.2.0",
    "passport-facebook": "1.0.3",
    "passport-github": "0.1.5",
    "passport-google-oauth": "0.1.5",
    "passport-local": "1.0.0",
    "passport-twitter": "1.0.2",
    "proteus-cluster": "1.0.6",
    "proteus-logger": "1.2.3",
    "rethinkdb": "1.12.0-1",
    "rethinkdb-pool": "0.0.4",
    "validator": "3.16.0"
  }

[steverandy]

Got the same error. I noticed it's because I used express 4.0 router.

express = require "express"
router = express.Router()
router.get "/", (req, res) -> res.render "index"
module.exports = router

[groundwater]

I tried reproducing this with the following snippet, using express@4.4.3

require('newrelic')

var http       = require('http')
var express    = require("express")
var bodyParser = require('body-parser')
var app        = express()

app.use(bodyParser.urlencoded())
app.use(bodyParser.json())
app.use(function(req,res,nxt){
  nxt()
})
app.use(function(err,req,res,nxt){
  nxt()
})
app.get("/", function (req, res) {
  res.send("index")
})

http.createServer(app).listen(8080)

I get no errors with newrelic@1.7.2. I am hesitant to include a fix without a repro case, or a test. We may be only patching a symptom versus fixing the root cause. We generally release every Thursday, so we still have some time to fix this before next release.

If you can help me refine the case and generate an error, that would be greatly appreciated.

[groundwater]

Thanks to @marcbachmann for the (slightly modified) repro case below:

require('newrelic');
var express = require('express');
var router = express.Router();

router.get('/1', function(req, res, next) {
  next();
});

router.get('/2', function(req, res, next) {
  next();
});

This produces the following error:

/Users/jacob/Projects/NewRelic/BUGFIX/issue-155/node_modules/newrelic/lib/instrumentation/shared/connect-express.js:135
          if (m.handle !== sentinel) {
               ^
TypeError: Cannot read property 'handle' of null
    at cb_filter (/Users/jacob/Projects/NewRelic/BUGFIX/issue-155/node_modules/newrelic/lib/instrumentation/shared/connect-express.js:135:16)
    at Array.filter (native)
    at Function.cls_wrapMiddlewareStack [as route] (/Users/jacob/Projects/NewRelic/BUGFIX/issue-155/node_modules/newrelic/lib/instrumentation/shared/connect-express.js:128:31)
    at Function.proto.(anonymous function) [as get] (/Users/jacob/Projects/NewRelic/BUGFIX/issue-155/node_modules/express/lib/router/index.js:446:22)
    at Object.<anonymous> (/Users/jacob/Projects/NewRelic/BUGFIX/issue-155/index.js:9:8)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)

I haven't resolved the underlying issue yet. Stay tuned.

[groundwater]

Just an update.

This is an error in our instrumentation, and we're hoping to release a fix this week.

[groundwater]

This should be fixed in 1.7.3.

Please let us know if this does, or does not resolve the issue.

Sorry about breaking things!

[oblador]

Still getting similar errors, but not on startup – only when requesting a page.

Using latest krakenjs which might complicate debugging, but doesn't seem to be involved judging by the stack trace.

TypeError: Cannot call method 'handle' of undefined
    at Function.app.handle (<project path>/node_modules/express/lib/application.js:124:16)
    at Layer.fn (<project path>/node_modules/express/lib/application.js:188:17)
    at Layer.eval [as handle] (eval at wrapHandle (<project path>/node_modules/newrelic/lib/instrumentation/express.js:246:41), <anonymous>:10:14)
    at trim_prefix (<project path>/node_modules/express/lib/router/index.js:252:17)
    at <project path>/node_modules/express/lib/router/index.js:216:9
    at Function.proto.process_params (<project path>/node_modules/express/lib/router/index.js:284:12)
    at Function.cls_wrapProcessParams [as process_params] (<project path>/node_modules/newrelic/lib/instrumentation/express.js:185:29)
    at next (<project path>/node_modules/express/lib/router/index.js:207:19)
    at next (<project path>/node_modules/express/lib/router/index.js:182:38)
    at <project path>/node_modules/newrelic/node_modules/continuation-local-storage/context.js:76:17

[groundwater]

@oblador this looks like a different issue, so I've moved it to #160

[marcbachmann]

@groundwater Thanks, version 1.7.3 solved the problem with express.Router.

[txase]

@marcbachmann Thanks for confirming! I'm going to close this issue now.