Error resolving path import specifiers

[aomarks]

The middleware appears to be trying to resolve import specifiers that are already paths, and erroring that it cannot resolve them. It should be ignoring them altogether:

Unable to resolve Node module specifier "./index-1.js" due to { Error: Cannot find module './index-1.js' from '/Users/aomarks/git/benchmarks/polymer/'
    at Function.module.exports [as sync] (/Users/aomarks/git/benchmarks/node_modules/resolve/lib/sync.js:71:15)
    at Object.exports.resolveNodeSpecifier (/Users/aomarks/git/benchmarks/node_modules/koa-node-resolve/src/support/resolve-node-specifier.ts:26:44)
    at koa_module_specifier_transform_1.moduleSpecifierTransform (/Users/aomarks/git/benchmarks/node_modules/koa-node-resolve/src/koa-node-resolve.ts:41:51)
    at countedSpecifierTransform (/Users/aomarks/git/benchmarks/node_modules/koa-node-resolve/src/koa-module-specifier-transform.ts:133:26)
    at enter (/Users/aomarks/git/benchmarks/node_modules/koa-node-resolve/src/transform-js-module.ts:27:42)
    at NodePath._call (/Users/aomarks/git/benchmarks/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/Users/aomarks/git/benchmarks/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/Users/aomarks/git/benchmarks/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/Users/aomarks/git/benchmarks/node_modules/@babel/traverse/lib/context.js:118:16)
    at TraversalContext.visitMultiple (/Users/aomarks/git/benchmarks/node_modules/@babel/traverse/lib/context.js:85:17) code: 'MODULE_NOT_FOUND' 

[usergenic]

I went and added some tests to look at resolution of relative paths, including the specific case of resolving a relative path to a file that doesn't exist https://github.com/Polymer/koa-node-resolve/blob/resolve-module-specifier-for-file-without-imports-and-exports/src/test/resolve-node-specifier.test.ts#L84 which is the only case I could concoct where that error would come up.

Is there any chance that in your case the ./index-1.js file doesn't exist at the time of the resolution?

The node resolution algorithm actually can't ignore relative paths because of the way node module resolution algorithm still has to transform relative path specifiers by adding missing file extensions, for example. ./index-1 should convert to ./index-1.js by node module resolution rules, when the file is present, for example.

[usergenic]

I also added tests to verify this wasn't some issue with missing import/export specifiers in index-1.js which actually makes sense because node module resolution algorithm doesn't care about file contents except package.json AFAICT.

[kevinpschaaf]

It looks like specifically when resolving either packages or relative paths in HTML from a URL with no subpath (e.g. http://localhost:8080 as opposed to http://localhost:8080/home or http://localhost:8080/index.html), then paths being resolved by transformHTML are resolved against the parent of the HTTP root instead of the HTTP root.

e.g.

server.ts:

...
app.use(nodeResolve({
  root: '/Users/me/server_root'
}));

index.html (being served from http://localhost:8080 root of server):

...
<script src="./node_modules/package/module.js"></script>

I believe this is due to a combination of these two lines:

• https://github.com/Polymer/koa-node-resolve/blob/master/src/koa-node-resolve.ts#L45 - resolves baseURL (in this case '/') against the root (e.g. '/Users/me/server_root') --> '/Users/me/server_root' to pass into modulePath
• https://github.com/Polymer/koa-node-resolve/blob/master/src/support/resolve-node-specifier.ts#L27 - takes the dirname of the modulePath --> '/Users/me' for basedir

Afaict this is not a problem when the baseURL is a file, as in URLs in HTML with file parts, or imports from JS where there's always a file present.

[usergenic]

@kevinpschaaf I am having trouble reproducing this issue. Can you provide a repro? Is it worth mentioning that in your example, the script tag doesn't have type=module?

[usergenic]

I just added unit to koa-node-resolve.test.ts that specifically handles routing an html file through a path of '/' and this is showing failures to resolve; so this may be a sufficient repro case. WIP

[usergenic]

Thanks, @kevinpschaaf I have a PR to fix this now in review #30

[usergenic]

@aomarks Does the published 1.0.0-pre.8 version with the #30 fix solve the problem you encountered when you posted this...a year ago 😲?