How to optimize webpack chunk

[SunXinFei]

I try to set the splitChunks ，Not effective， so how to optimize the chunk
mathjs: {

        name: 'chunk-mathjs,
        test: /[\\/]node_modules[\\/]_?mathjs(.*)/,
        priority: 10
      },

[josdejong]

See https://mathjs.org/docs/custom_bundling.html