Suggestion about error handler in express

I have this idea when I am at Streaming Content with Express (2).
As the tutorial states, error handler of express always respond with HTML describing the error the server has.
If we change the Content-Type
to something except text/html
, for example, application/json
, then browser will receive a HTML response while the header of which is not application/json
. Browser will be confused due to header and content mismatch.
According to the last step of Streaming Content with Express (2), when I navigate to http://localhost:3000/articles?type=json
, the response looks like this in the browser:
Maybe we can reset the response type in the error handler to inform the clients of the correct Content-Type
.
// render the error page res.type('text/html') res.status(err.status || 500); res.render('error');
Comments
-
Another observation about express is streaming error handling.
Say pipe some stream tores
.someStream.pipe(res)
And something goes wrong during the process before
end
event of the stream emitted.someStream.destroy()
Before
someStream.destroy()
being invoked, HTTP headers have already been sent to the client.
If I propagateError [ERR_STREAM_PREMATURE_CLOSE]
tonext()
function of the route handler, express will also invokeres.render('error');
inapp.js
to respond to the HTTP request. Then express will complain thatError [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
So I would like to know what is the appropriate way to handle error when piping stream to HTTP response. The default behavior of express doesn't seem to be the best solution.
0 -
const { finished } = require('stream') // handler setup etc etc handler.get('/foo/bar', (req, res, next) => { const stream = createStream(req.data.whatever) finished(stream, (err) => { if (err) return next(err) res.end('finished') next() }) })
Streams can close for various reasons, using the
finished
function covers all the cases.If you're looking to pipe you can use
stream.pipeline
to combine the best of both.pipe
andfinished
:const { pipeline } = require('stream') // handler setup etc etc handler.get('/foo/bar', (req, res, next) => { const stream = createStream(req.data.whatever) pipeline(req, stream, res, next) })
0
Categories
- 9.9K All Categories
- 29 LFX Mentorship
- 82 LFX Mentorship: Linux Kernel
- 465 Linux Foundation Boot Camps
- 266 Cloud Engineer Boot Camp
- 94 Advanced Cloud Engineer Boot Camp
- 43 DevOps Engineer Boot Camp
- 29 Cloud Native Developer Boot Camp
- 1 Express Training Courses
- 1 Express Courses - Discussion Forum
- 1.6K Training Courses
- 18 LFC110 Class Forum
- 4 LFC131 Class Forum
- 19 LFD102 Class Forum
- 132 LFD103 Class Forum
- 9 LFD121 Class Forum
- 60 LFD201 Class Forum
- LFD210 Class Forum
- 1 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum
- 23 LFD254 Class Forum
- 544 LFD259 Class Forum
- 100 LFD272 Class Forum
- 1 LFD272-JP クラス フォーラム
- 1 LFS145 Class Forum
- 20 LFS200 Class Forum
- 739 LFS201 Class Forum
- 1 LFS201-JP クラス フォーラム
- 1 LFS203 Class Forum
- 36 LFS207 Class Forum
- 295 LFS211 Class Forum
- 53 LFS216 Class Forum
- 45 LFS241 Class Forum
- 39 LFS242 Class Forum
- 33 LFS243 Class Forum
- 10 LFS244 Class Forum
- 27 LFS250 Class Forum
- 1 LFS250-JP クラス フォーラム
- 131 LFS253 Class Forum
- 964 LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 85 LFS260 Class Forum
- 124 LFS261 Class Forum
- 29 LFS262 Class Forum
- 78 LFS263 Class Forum
- 15 LFS264 Class Forum
- 10 LFS266 Class Forum
- 17 LFS267 Class Forum
- 16 LFS268 Class Forum
- 14 LFS269 Class Forum
- 194 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- 206 LFW211 Class Forum
- 148 LFW212 Class Forum
- 890 Hardware
- 212 Drivers
- 74 I/O Devices
- 44 Monitors
- 115 Multimedia
- 206 Networking
- 99 Printers & Scanners
- 85 Storage
- 747 Linux Distributions
- 88 Debian
- 64 Fedora
- 13 Linux Mint
- 13 Mageia
- 24 openSUSE
- 133 Red Hat Enterprise
- 33 Slackware
- 13 SUSE Enterprise
- 354 Ubuntu
- 468 Linux System Administration
- 38 Cloud Computing
- 67 Command Line/Scripting
- Github systems admin projects
- 93 Linux Security
- 77 Network Management
- 107 System Management
- 48 Web Management
- 61 Mobile Computing
- 22 Android
- 25 Development
- 1.2K New to Linux
- 1.1K Getting Started with Linux
- 525 Off Topic
- 127 Introductions
- 211 Small Talk
- 19 Study Material
- 782 Programming and Development
- 256 Kernel Development
- 492 Software Development
- 919 Software
- 255 Applications
- 181 Command Line
- 2 Compiling/Installing
- 76 Games
- 316 Installation
- 46 All In Program
- 46 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)