Fix missing child bundles throwing an error

[dabbott]

This fixes an issue introduced in #376, where getChildAssetBundles sometimes doesn't find the given statAsset.name and returns undefined, which later causes an error.

This probably isn't a great fix, and I'm not sure specifically how to reproduce the issue, but it seems harmless enough that I'll be using it for now at least 😅

[jsf-clabot]

All committers have signed the CLA.

[dabbott]

@jsf-clabot rerun

[valscion]

Thanks! Would you be able to setup a test with stats.json that breaks, similar to files in here? https://github.com/webpack-contrib/webpack-bundle-analyzer/tree/master/test/stats

Those files are used by tests defined in https://github.com/webpack-contrib/webpack-bundle-analyzer/blob/master/test/analyzer.js

[th0r]

@valscion let's not merge it without a test please.

[valscion]

@valscion let's not merge it without a test please.

👍 sounds good to me!

[masterkidan]

@dabbott : It would be great if you can debug a bit deeper, my understanding is that we eliminate assets generated by plugins like HtmlWebpackPlugin in the regex/assetfilter (only js assets are analyzed). It looks like in your webpack config something with HtmlWebpackPlugin is generating js assets, can you share the config so I can understand the issue a bit better?

[dabbott]

@masterkidan Thanks for checking this out. Here's my webpack config: https://github.com/dabbott/react-native-web-player/blob/58e49839516a32a91267510b550823e644b72364/webpack/webpack.config.js.

If you'd like, you should be able to pull down that react-native-web-player/webpack-bundle-analyzer branch and run yarn build to see the error (if you have webpack-bundle-analyzer linked locally so you're pointing to master). I don't know how webpack assets are organized at all really, so I probably won't be much help in making a better fix, but if you have suggestions or a fix to test I can definitely try it out.

[masterkidan]

@dabbott : I think this may be because of the fact your template is an 'ejs' file. This is not something that gets filtered out by the regex, but the template compilation is a child compilation, I think a slightly better way would be to check why
the following bit of code in analyzer.js

// Picking only `*.js or *.mjs` assets from bundle that has non-empty `chunks` array
  bundleStats.assets = _.filter(bundleStats.assets, asset => {
    // Removing query part from filename (yes, somebody uses it for some reason and Webpack supports it)
    // See #22
    asset.name = asset.name.replace(FILENAME_QUERY_REGEXP, '');

    return FILENAME_EXTENSIONS.test(asset.name) && !_.isEmpty(asset.chunks) && isAssetIncluded(asset.name);
  });

is not filtering out the asset, and fix it here instead :) .

You can use https://github.com/masterkidan/worker-loader-no-stats as a base and add a simple index.ejs template with a WebpackHtlmPlugin to process it.... I am not sure when I will be able to get to it on my own.

[dabbott]

Ok! I was able to track this down. This happens when workers contain dynamic imports with import('./some-dep.js'). I added a test case (generated via https://github.com/dabbott/worker-loader-dynamic-imports).

I think this is probably in an OK state to merge, and @masterkidan if you have time you could do a better fix in the future.

[th0r]

@dabbott so, what is the actual reason for the exception? What asset it tries to find but it's not there?

[dabbott]

We're looking for "1.bundle.worker.js" as assetName in:

function getChildAssetBundles(bundleStats, assetName) {
  return _.find(bundleStats.children, (c) =>
    _(c.assetsByChunkName)
      .values()
      .flatten()
      .includes(assetName)
  );
}

That name doesn't exist in assetsByChunkName. (Maybe cause it's not a named chunk? It does exist in c.chunks I believe)