New Node.js static server example

[tshemsedinov]

Summary

• Totally rewrite example in a modern style
• Add path traversal vulnerability issue
• Remove half of MIME types not to overload example
• Use file streams to reduce memory usage for big files

Motivation

Improve and renew legacy codebase.

Metadata

• Adds a new document
• Rewrites (or significantly expands) a document
• Fixes a typo, bug, or other error

[github-actions]

Preview URLs

• /en-US/docs/Learn/Server-side/Node_server_without_framework

External URLs (1)

URL: /en-US/docs/Learn/Server-side/Node_server_without_framework
Title: Node.js server without a framework

• https://nodejs.org/en/ (1 time) (Note! This may be a new URL 👀)

(this comment was updated 2022-09-28 00:13:22.686039)

[hamishwillee]

@tshemsedinov This is excellent thanks.

@teoli2003 I've just done a basic subedit, not a technical review - left that for you.

[tshemsedinov]

@hamishwillee thanks, I'll fix that in a few days, and can provide more simple examples of modern pure node.js and framework-agnostic approach.

Refs: https://github.com/mdn/content/discussions/13124

[Artuomka]

+1. Great idea!

[hamishwillee]

Apologies @tshemsedinov - I did a subedit back in February but then thought I'd handed over to @teoli2003 for technical review. Obviously I did not do so properly

@teoli2003 Can you review and tell me if you are happy with this as a technical update?

My take on it is that it is a little "succint" for a learn article - but then so was the original. It lost some of the possible errors from the file read too. What I don't know is if this is a pattern that we would be OK for people to copy. Also whether the introductory statement is true - i.e. is this everything needed for a basic static file server.

[Josh-Cena]

I'm more familiar with Node than web (though I'm not a back end so I'm not that familiar with HTTP servers). The code here looks good enough to be copied—although it's definitely quite simple!

[Josh-Cena]

Note: as a mid-term goal I'd like MDN Node tutorials to embrace Node ESM. More and more dependencies are migrating to ESM and you can't require ESM, which means for forward compatibility all user projects should start as ESM.

[teoli2003]

@Josh-Cena: I think this is a great point. To give it more visibility, can you start a discussion about it (I believe the consensus will be easy to reach) at mdn/mdn-community ?

[Josh-Cena]

Ah yes, I should—just haven't got to it yet...

[Josh-Cena]

mdn/mdn-community#191

[tshemsedinov]

@hamishwillee new example don't need to check if (error.code === 'ENOENT') because it checks is file exists before reading it and sends 404.html to the client with HTTP 404 code. So it completely repeats behavior of previous example and even extends it with big-files support but in a modern node way. I can extend this example with:

• Memory cache to deduce reply latency
• Reload cache watching for file changes
• Generate directory index in html to select files
• Support HTTP range requests

Listed will take about +10 lines each ☺

[Josh-Cena]

Before we reached resolution with mdn/mdn-community#191, could you keep this CJS-only? This is simply confusing without another explanatory document.

[tshemsedinov]

@Josh-Cena done

[hamishwillee]

Thanks @tshemsedinov .

@Josh-Cena @teoli2003 I think we should get this in when you are happy. However it might be good to extend this in some or all of the ways outlined in #13113 (comment) as a post process - in particular if that can be done in separate sections such that a user can learn how each part is put together.

Do you have options about what you think such an example should do in the ideal case?

[estelle]

merging. If there are still issues, we can edit again.

[charlesvg]

Providing an ESM version 👍

Assuming that from now on all codebases across the globe have migrated to ESM and not providing a CJS version equals to giving those who maintain legacy no other choice than to look elsewhere for a simple node http server.

PS, who performed a code review on this?
How semantic would you say the function name prepareFile is?
How readable would you say the function prepareFile is......?

[Josh-Cena]

@charlesvg Passive-aggressive comments have no place on MDN and is borderline CoC violation.

The argument that there are people "maintaining legacy CJS applications" while needing to read learning materials to know how to write a simple HTTP server seems unlikely. We always assume people start from scratch and have no tech debt; otherwise it's hard for us to set any common ground.

The argument is also non-unique to ESM. You could ask: why does MDN use async/await? Why does MDN use at()? All of these syntaxes are well-supported in all Node LTS versions, so they are not experimental and we as editors have no reason to fear using them. If for some reason your environment doesn't support them, the solution is to use a transpiler/polyfill. Babel/tsc is almost inevitable on server-side as well, if you ever want to enforce type checking and/or extension syntaxes.

If you find prepareFile unreadable, feel free to send a refactor PR and let us review how it can be improved. The current code meets all engineering standards and is not less readable than other code examples on MDN. But ESM is a ship that's sailed—we'll not write new CJS code in our learning area examples.