polyfill process and Buffer

Author: eggplantzzz

packages/contract/webpack.config.js

@@ -26,10 +26,12 @@ module.exports = {
     }),
     new webpack.ProvidePlugin({
       process: "process/browser"
+    }),
     })
   ],
   resolve: {
     fallback: {
+      buffer: require.resolve("buffer"),
       crypto: require.resolve("crypto-browserify"),
       http: require.resolve("stream-http"),
       https: require.resolve("https-browserify"),