I don't disagree with your general sentiment, but you can be pragmatic and useful to users without bending to their every need. It's doesn't mean you're plugging your ears, it means you're being careful. Node and NPM are moving targets; chasing compatibility itself is not practical, and Dahl explicitly mentioned in his intro to Deno that Node compatibility was not a great idea (he was right).

If your team/company is reliant on Node packages, it does not make any sense to go for another runtime.

There is a difference between Node compatibility and NPM compatibility though. NPM may have started with Node, but it has become part of the core development process for front-end web development. One of the main purposes of Deno is to decrease the gap between frontend JS development and backend JS development, and adding NPM support furthers that goal.

What doesn't make sense is adding a compatibility layer for all the Node specific functionality that has since become redundant with new Web standards.

Given that a significant number of packages in npm won't work without Node compatibility, I'm not sure the distinction makes much of a difference.

> If your team/company is reliant on Node packages, it does not make any sense to go for another runtime

If Deno does some things better than node, and nothing worse, then NPM support means users can gradually migrate from node. Any of those improvements might be enough motivation if they help your use-case.

AFAICT, there still isn’t a killer reason for my mature project to migrate, but removing the NPM blocker means I can consider it as soon as they release something that fits my use case.

Here's an example where NPM compatibility allowed me to use Deno where I otherwise couldn't:

I've got a personal blog that had been on Node. I wanted to port it to Deno. I ported all the server code to be Deno-idiomatic, I dropped dependencies in favor of Deno standard library functions etc, it was great.

But I needed a markdown parser with specific special features that my corpus of existing documents already used. I researched Deno-native ones, I found one or two half-baked markdown parsers but none that supported the features I needed.

So, with a little fiddling, I got the (mature, featureful) NPM markdown library I'd been using before, working directly within the Deno version of my site. Markdown in -> HTML out. Everything else is lovely pure Deno code, and this one small piece of functionality didn't become a show-stopper because the team chose to support what I needed.

I tend to be an idealist in my programming - that's why I like Deno - but the absolutism I'm seeing in this thread is bizarre. An ecosystem is a huge asset, and you don't rebuild one - especially one as vibrant as NPM - overnight. It takes time, and in that time people can stop caring about your runtime and just use another one so they can get on with their lives. Projects like Deno are beholden to network effects; if you shun the network, the project dies.

That is a weird example, because you make it sound like you easily could have just extracted the Deno-compatible JS, and made a regular ECMAScript Module and avoided an NPM compatibility layer at all.

In fact, I did this exact thing to use marked[1] with QuickJS[2]. Obviously, QuickJS doesn't have an NPM compatibility layer because it doesn't need one, and neither does Deno. The great thing is the resulting .js file can easily be a Deno module as well.

> I tend to be an idealist in my programming - that's why I like Deno - but the absolutism I'm seeing in this thread is bizarre

I don't really see any absolutism in this thread, it's just a disagreement. Yes, NPM compat is great for adoption. I'm arguing it's not great for the runtime, and that it adds tech debt, and slows the team down from doing (imo) more creative things. It also adds more to the binary.

[1] https://raw.githubusercontent.com/markedjs/marked/master/lib... [2] https://bellard.org/quickjs/quickjs.html

> because you make it sound like you easily could have just extracted the Deno-compatible JS, and made a regular ECMAScript Module and avoided an NPM compatibility layer at all

"Easily" is relative. I'm sure one could port the library I'm using to be Deno-compatible, maybe with less trouble than some other libraries because it's unlikely to use many system APIs, but it's also a large, significant, mature library; we're not talking about leftpad here.

And I'm just making a blog site. I want to get on with my life, not spend hours or days fiddling with all the long-tail incompatibilities I would probably run into making a Deno-compatible fork of a major library that I'm not planning to maintain.

If I'm writing a new library that I've already decided to put effort into, I'm likely to make it Deno-compatible from the get-go. But porting something significant to Deno is not trivial, even where it is straightforward. Things take time, and over a whole ecosystem it adds up, and we can't erase that labor gap from the discussion.