Resolve `<module-name>/index.js` about rollup-plugin-includepaths

[darlanalves]

Hello @runspired! I'm not sure if I get your use case, so correct me here if I'm wrong:

// file a.js placed on file-a/a.js
import B from 'b';

// file index.js placed on b/index.js
// ...

Is this the case?

I'm actually wondering if this /index.js case is good to keep on plugin. It doubles the amount of I/O access and makes the plugin even more slow. I added it to support these imports inside a node module I needed.

Anyway, if I'm not mistaken, I just need to add one more check in this line
https://github.com/dot-build/rollup-plugin-includepaths/blob/master/src/plugin.js#L159

[nilssolanki]

I would appreciate this feature as well (coming from webpack, this was really useful), even if it slightly alters the performance.

[runspired]

@darlanalves yes, my specific usage is that a different build step has already pushed all needed modules into a tmp directory. So import 'b'; which should resolve to <dir>/b/index.js is unfound.

Beyond that though, it's also how most imports from node_modules are going to behave. The main file is very often an index.

[darlanalves]

Ok folks! Sorry the delay, busy week. So, I have this layout:

app.js
tmp/file-a/a.js
tmp/b/index.js

// app.js
import {A} from 'file-a/a';

export default A;

// tmp/file-a/a.js

import B from 'b';

class A extends B {}

export { A };

// /tmp/b/index.js
class B {}

export default B;

... and this config file:

import includePaths from 'rollup-plugin-includepaths';

let includePath = includePaths({
    paths: ['tmp'],
    extensions: ['.js']
});

export default {
    entry: 'app.js',
    format: 'cjs',
    dest: 'bundle.js',
    plugins: [includePath]
};

With that, B was included for A, and both included on final bundle. Published a new version on npm already. Let me know if it fixes your issues.