Fix "Can't set headers after they are sent" errors #1176
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This PR tries to fix "Can't set headers after they are sent" errors. That are a lot of situations where this error can occurs. In my case, it is happening because I have others middlewares (in an expressjs application that tries to proxy requests). Some of those middlewares (like [passportjs](http://passportjs.org/), or [cors](https://www.npmjs.com/package/cors)) can run ```res.end()``` and when the proxy receive a response, it is already finished. So, it is necessary to test if we can write on the user response when the proxy response is ready. I think it could also fix http-party#930, http-party#1168, http-party#908
|
Tests are failing in Node.js 0.10.x/0.12.x, but it's unrelated to my changes. See #1167. |
jakefurler
reviewed
Jun 14, 2017
| if(web_o[i](req, res, proxyRes, options)) { break; } | ||
| if (!res.headersSent) { | ||
| for(var i=0; i < web_o.length; i++) { | ||
| if(web_o[i](req, res, proxyRes, options)) { break; } |
There was a problem hiding this comment.
I think this is a better fix: #1182
There was a problem hiding this comment.
Hi @Frogmella,
I think that your your commit is ok and we should avoid the writeHead function. But if the headers are already sent, does not makes sense to call res.statusCode = proxyRes.statusCode;. The response status code and headers were already sent to client, so you can not modify it anymore.
jcrugzz
approved these changes
Apr 19, 2018
|
Thanks for the contribution @thiagobustamante. I will cherry-pick this into my maintenance branch that will be merged in today. |
|
superseded by #1251 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR fix "Can't set headers after they are sent" errors.
That are a lot of situations where this error can occurs. In my case, it is happening because I have others middlewares (in an expressjs application that tries to proxy requests). Some of those middlewares (like passportjs, or cors) can run
res.end()and when the proxy receive a response, it is already finished.So, it is necessary to test if we can write on the user response when the proxy response is ready.
I think it could also fix #930, #1168, #908 and #867