Disable core packages

[egormalyutin]

Hello. Can I disable all core packages support?

[egormalyutin]

I already came up with hack like

if (require("resolve/lib/core.json")[pkg]) {
	pkg += "/"
}
console.log(resolve(pkg))

[ljharb]

What's your use case?

[ljharb]

also that check is very incorrect; use require('resolve/lib/is-core')(pkg), if anything.

[egormalyutin]

@ljharb I just want to find modules installed in node_modules rather than core modules

[egormalyutin]

@ljharb Actually I used Object.property.hasOwnProperty and everything (it's just a short example), but thanks anyway!

[ljharb]

That’s not correct, though, because of the semver ranges. Use the isCore function.

You can do that by appending a slash, just like you can in node.

[egormalyutin]

@ljharb Okay, but can I add core module to the list?

[ljharb]

Not without doing hacky unsupported things. What's your use case?

[egormalyutin]

@ljharb I'm trying to create a simple small module bundler.

Can I submit a PR with support of adding or removing core modules?

[ljharb]

browserify already is a simple small module bundler, and already uses resolve with existing options to achieve the same goal. If you can't use an existing bundler, i'd suggest reading how they do it :-)

I don't think a PR is warranted here.

[egormalyutin]

@ljharb I'm not trying to create a module bundled because I don't know how to use them, but because I want to understand more how they work

[arikon]

@ljharb My case is:

• I want to recursively copy all the dependencies, found in package.json
• one of the dependency names is clashing with the core module (buffer in my case), and is installed in node_modules
• resolve knows buffer as a core module, so it don't even try to find a module in node_modules, it just returns buffer
• but I expected a full module path

[arikon]

I think the fix could be isCore() check happening after loadNodeModulesSync() call here:
https://github.com/browserify/resolve/blob/master/lib/sync.js#L88-L93

[octogonz]

I think the fix could be isCore() check happening after loadNodeModulesSync() call here:
https://github.com/browserify/resolve/blob/master/lib/sync.js#L88-L93

@arikon Hrmm.... I just tried the following test with Node 10:

$ npm init
$ npm install buffer
$ node -e console.log(require.resolve('buffer'))

It resolves to "buffer" instead of "node_modules/buffer". In other words, Node.js system modules seem to take precedence over installed NPM packages with the same name. Thus perhaps resolve.sync() is handling this case accurately.

Which package did you find that depends on "buffer"? Does it import the system module and work correctly with that? Or is it someone bypassing the Node.js module resolution? (In which case we may still want a resolve feature to disable/hook isCore().)

[ljharb]

Indeed, this is correct. Only bundlers would use the installed one (which can be chosen via some function options you can read about in the readme); buffer/ would be how you'd do it in node and resolve by default.

[arikon]

@octogonz typeorm depends on buffer package

[octogonz]

And I see they indeed do:

 window.Buffer = require("buffer/").Buffer;

[octogonz]

@ljharb In our case we are crawling dependencies and devDependencies from package.json. So if a name appears in package.json, we can reasonably assume that it is meant to be an NPM package, not a system module. And we could handle this by always appending / before calling resolve.sync().

This solution feels slightly clumsy, though. It would be ideal if resolve provided an explicit option to disable isCore(). Otherwise everywhere we do that, we have to include a code comment explaining the unfamiliar / suffix. And we have to make sure the string doesn't already contain /, etc.

[ljharb]

You're right you'd need code like inPackageJSON(x) && isCore(x) ? `${x}/` : x, but that doesn't seem particularly troublesome?

[octogonz]

inPackageJSON(x) && isCore(x) ? `${x}/` : x isn't troublesome to write. Merely confusing for people who read the code later.

[octogonz]

Another problem is that the error messages come back like this:

ERROR: Cannot find module 'jquery/' from 'C:/my-project'

If I saw this error, my first thought would be "Oh, we must be accidentally appending a slash somewhere".

[ljharb]

Why would the slash be appended for a non-core module? or do you mean, in the case where you unconditionally append a slash.

[ljharb]

#233 has provided this.

[octogonz]

Thanks for implementing this! We'll use it!

or do you mean, in the case where you unconditionally append a slash.

Yes, to skip core modules we had to unconditionally append a slash, and then the resulting error message would have a weird slash in it.