Server doesn't work with `esm` package

🐛 Bug Report

When using @loadable/server with the esm package, when you instantiate the ChunkExtractor you will get the following error:

TypeError: Cannot read property 'filename' of undefined
    at /Users/brandonp/Sites/myrepo/node_modules/esm/esm.js:1:252056
    at smartRequire (/Users/brandonp/Sites/myrepo/node_modules/@loadable/server/lib/util.js:23:32)
    at new ChunkExtractor (/Users/brandonp/Sites/myrepo/node_modules/@loadable/server/lib/ChunkExtractor.js:173:50)
    at renderApp (/Users/brandonp/Sites/myrepo/src/backend/renderApp.js:63:29)
    at process._tickCallback (internal/process/next_tick.js:68:7)

To Reproduce

Steps to reproduce the behavior:

Run the following with a valid nodeStats path:

      const nodeExtractor = new ChunkExtractor({
        statsFile: nodeStats,
        entrypoints: ['main']
      });

Expected behavior

ChunkExtractor successfully loads and uses the required nodeStats file path.

 const nodeStats = path.resolve('./dist/backend/app/loadable-stats.json');`

The fix (IMO)

You’re currently using module.require. If I tweak this line to read as follows:

  try {
    // This will fail with 'esm' because module not accessible
    return eval('module.require')(modulePath);
  } catch (err) {
    // Fallback on normal require
    return require(modulePath);
  }

More about why module.require is not defined here.

I am more than happy to open a PR for this, but unsure if this is the solution you want to take. Please let me know!

Run npx envinfo --system --binaries --npmPackages @loadable/component,@loadable/server,@loadable/webpack-plugin,@loadable/babel-plugin --markdown --clipboard

Paste the results here:

## System:
 - OS: macOS Mojave 10.14.6
 - CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
 - Memory: 966.62 MB / 16.00 GB
 - Shell: 5.3 - /bin/zsh
## Binaries:
 - Node: 10.15.1 - ~/.nvm/versions/node/v10.15.1/bin/node
 - Yarn: 1.17.3 - /usr/local/bin/yarn
 - npm: 6.4.1 - ~/.nvm/versions/node/v10.15.1/bin/npm
## npmPackages:
 - @loadable/babel-plugin: ^5.10.3 => 5.10.3 
 - @loadable/component: ^5.10.3 => 5.10.3 
 - @loadable/server: ^5.10.3 => 5.10.3 
 - @loadable/webpack-plugin: ^5.7.1 => 5.7.1 

[brandon-pereira]

@theKashey PR opened which changes eval('module.require') to eval('require'). @neoziro if you have any insights as to why module.require was used I’d be interested to hear!

Let me know if I can change/improve anything else, happy to help. Thanks for making this package 😃

[brandon-pereira]

Okay, I can switch it to using a simple require. Should I add foolwebpack as a dependency or should I just copy the logic they use to require? Not sure if you want another dependency added.