Please support multiple entry points for library mode

[franktopel]

Clear and concise description of the problem

I'm using Vite.js to build a webcomponent library for a customer.

        lib: {
            entry: path.resolve(__dirname, 'src/webcomponents.js'),
            formats: ['es'],
            name: 'webcomponents',
        },

This does perfectly create the desired output:

vite v2.4.4 building for production...
✓ 32 modules transformed.
dist/webcomponents.es.js   36.46kb / brotli: 10.31kb
dist/webcomponents.es.js.map 101.33kb
dist/style.css                  117.61kb / brotli: 82.97kb

In the same project, we also build the application that uses this library, which basically comprises of web components as well, which serve as views. So I need a second entry point:

        lib: [{
            entry: path.resolve(__dirname, 'src/webcomponents.js'),
            formats: ['es'],
            name: 'webcomponents',
        },
        {
            entry: path.resolve(__dirname, 'src/views.js'),
            formats: ['es'],
            name: 'views',
        }],

Unfortunately, that results in an error:

vite v2.4.4 building for production...
error during build:
TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received undefined
...

Suggested solution

Instead of a single entry point for libarary mode, allow an array of entry points.

Alternative

I've tried working around this limitation by using rollupOptions instead, but wasn"t able to figure it out:

rollupOptions: [
    {
        input: path.resolve(__dirname, 'src/webcomponents.js'),
        output: {
            file: path.resolve(__dirname, 'dist/webcomponents.js'),
            format: 'es'
        },
    }, {
        input: path.resolve(__dirname, 'src/views.js'),
        output: {
            file: path.resolve(__dirname, 'dist/views.js'),
            format: 'es'
        }
    }
],

Unfortunately, this does not create the files I expect:

dist/index.html                                3.03kb
dist/assets/index.1a413bf8.css                 6.54kb / brotli: 1.96kb
dist/assets/vendor.ef70301d.js                 11.19kb / brotli: 3.72kb
dist/assets/vendor.ef70301d.js.map             45.39kb
dist/assets/index.fa2e2112.js                  31.74kb / brotli: 7.88kb
dist/assets/index.fa2e2112.js.map              73.46kb

Additional context

I've read and upvoted #1736 and wanted to turn this into a feature request.

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[franktopel]

Closed in favor of #4530