node.js - Read For Learn

Error: Can’t set headers after they are sent to the client

The res object in Express is a subclass of Node.js’s http.ServerResponse (read the http.js source). You are allowed to call res.setHeader(name, value) as often as you want until you call res.writeHead(statusCode). After writeHead, the headers are baked in and you can only call res.write(data), and finally res.end(data). The error “Error: Can’t set headers after they are sent.” means that you’re already in the Body or Finished … Read more

What is this JavaScript “require”?

So what is this “require?” require() is not part of the standard JavaScript API. But in Node.js, it’s a built-in function with a special purpose: to load modules. Modules are a way to split an application into separate files instead of having all of your application in one file. This concept is also present in other languages … Read more

Client on Node.js: Uncaught ReferenceError: require is not defined

This is because require() does not exist in the browser/client-side JavaScript. Now you’re going to have to make some choices about your client-side JavaScript script management. You have three options: Use the <script> tag. Use a CommonJS implementation. It has synchronous dependencies like Node.js Use an asynchronous module definition (AMD) implementation. CommonJS client side-implementations include (most of them require a build step before you … Read more

Please run `npm cache clean`

As of npm@5, the npm cache self-heals from corruption issues and data extracted from the cache is guaranteed to be valid. If you want to make sure everything is consistent, use npm cache verify instead. On the other hand, if you’re debugging an issue with the installer, you can use npm install –cache /tmp/empty-cache to use a temporary cache instead … Read more

How can I completely uninstall nodejs, npm and node in Ubuntu [closed]

Then go to /etc/apt/sources.list.d and remove any node list if you have. Then do a Check for any .npm or .node folder in your home folder and delete those. If you type you can see the location of the node. Try which nodejs and which npm too. I would recommend installing node using Node Version Manager(NVM). That saved a lot of headache for me. You … Read more

Does anyone knows what “rimraf” means?

Ok for the recursive options when deleting files, but what is rimraf? Is it an acronym? Does it come from words combination? The word is fairly pleasant, I would like to know where does it come from.

How to fix “ReferenceError: primordials is not defined” in Node.js

I hit the same error. I suspect you’re using Node.js 12 and Gulp.js 3. That combination does not work: Gulp.js 3 is broken on Node.js 12 #2324 A previous workaround from Jan. does not work either: After update to Node.js 11.0.0 running Gulp.js exits with ‘ReferenceError: internalBinding is not defined’ #2246 Solution: Either upgrade to … Read more

Getting a UnhandledPromiseRejectionWarning when testing using mocha/chai

The issue is caused by this: If the assertion fails, it will throw an error. This error will cause done() never to get called, because the code errored out before it. That’s what causes the timeout. The “Unhandled promise rejection” is also caused by the failed assertion, because if an error is thrown in a … Read more

How do I debug error ECONNRESET in Node.js?

A simple tcp server I had for serving the flash policy file was causing this. I can now catch the error using a handler:

Node.js getaddrinfo ENOTFOUND

In Node.js HTTP module’s documentation: http://nodejs.org/api/http.html#http_http_request_options_callback You can either call http.get(‘http://eternagame.wikia.com/wiki/EteRNA_Dictionary’, callback), the URL is then parsed with url.parse(); or call http.get(options, callback), where options is Update As stated in the comment by @EnchanterIO, the port field is also a separate option; and the protocol http:// shouldn’t be included in the host field. Other answers … Read more

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