modified-named-chunks.webpack.config.js

// webpack.config.js 
// ...
plugins: [ 
  // ... 
  new webpack.NamedChunksPlugin((chunk) => { 
    if (chunk.name) { 
      return chunk.name; 
    } 
    return chunk.modules.map(m => path.relative(m.context, m.request)).join("_"); 
  }), 
]

- return chunk.modules.map(m => path.relative(m.context, m.request)).join("_"); 
+ return chunk.mapModules(m => path.relative(m.context, m.request)).join("_"); <= webpack >= v3.0.0

😛

return Array.from(chunk.modulesIterable, m => path.relative(m.context || '', m.request)).join('_')