config file not correctly processed

[mvolkmann]

Checklist

• Did you run the analyzer with the --dev flag to get more information?
• Did you create a minimal reproduction in the playground? I don't see a way to use a config file in the playground.

I have a project that contains a custom-elements-manifest.config.js file that contains the following:

export default {
  exclude: [
    "coverage/**",
    "src/stories/**",
    "storybook-static/**",
  ],
};

The excludes are not being honored, as evidenced by the generated custom-elements.json file containing descriptions of things found in files under the coverage directory. I debugged this and discovered an issue in the getUserConfig function defined in packages/analyzer/src/utils/cli-helpers.js. The object it returns looks like this:

{
  __esModule: true,
  default: {
    exclude: [
      'coverage/**',
      'custom-elements-manifest/**',
      'src/stories/**',
      'storybook-static/**'
    ]
  }
}

I expected it to look like this:

{
  exclude: [
    'coverage/**',
    'custom-elements-manifest/**',
    'src/stories/**',
    'storybook-static/**'
  ]
}

This is a problem in the mergeGlobsAndExcludes function which contains this line:

    ...(userConfig?.exclude?.map((i) => `!${i}`) || []),

The reason is that the userConfig object doesn't have an exclude property. Instead it has a default property whose value is an object that has an exclude property.

Expected behavior

I expected the excludes described in the config file to be honored.

[MattiasBuelens]

This seems to be a problem with how the analyzer loads the configuration file. I was trying to load custom-elements-manifest.config.mts, which should be recognized as a TypeScript ESM module. However, @web/config-loader only recognizes .mjs and .cjs, see modernweb-dev/web#2465.

As a workaround, you could try renaming your config file to .cjs and using CommonJS-style module.exports instead of export default.