Sometimes `gatsby build` doesn't minify the commons-*.js file

[resir014]

• Gatsby version: gatsby 1.9.106, gatsby-cli 1.1.20
• Node version: 8.9.0
• OS: Windows 10 (x64)

I've brought up this issue on the Reactiflux chat the other day, but I'm going to put it as an issue here since it's potentially an issue on both Gatsby and Netlify.

On some occasions,gatsby build doesn't generate a minified commons-*.js file:

This could sometimes result in the React Devtools saying that I'm not running a minified build of React whenever I deploy to Netlify with Continuous Deployment:

Running gatsby build and manually deploying everything to Netlify will cause React Devtools to behave, however the resulting commons-*.js file remains unminified.

[sebastienfi]

See my post here, maybe it helps #2771

[resir014]

@sebastienfi ah, thanks a lot! I can close this as a duplicate then.

[resir014]

Reopening this to post my solution.

gatsby-node.js

exports.modifyWebpackConfig = ({ config, stage }) => {
  if (stage === 'build-javascript') {
    // Temporary workaround.
    // Here we override the Webpack plugin during the `build-javascript` stage to make everything
    // compile down to es5 - turns out Webpack 1's UglifyJsPlugin doesn't like that we have some
    // ES6 stuff littered in our final bundle...
    config.loader('typescript', {
      test: /\.tsx?$/,
      loaders: ['ts-loader']
    })
  }
}

tsconfig.json (note the es5 compile target)

{
  "compilerOptions": {
    "outDir": "./dist/",
    "sourceMap": true,
    "noImplicitAny": true,
    "module": "commonjs",
    "target": "es5",
    "jsx": "react",
    "lib": ["dom", "esnext"]
  },
  "include": [
    "./src/**/*"
  ]
}

[Cammisuli]

I tried to follow the advice from @resir014's post, but I kept getting Cannot read property 'initial' of undefined.

So, I found the proper solution for me, and maybe this could help others in the future. In the plugin section of gatsby-config.js, specify the typescript target in compilerOptions to 'es5'

{
  resolve: "gatsby-plugin-typescript",
  options: {
    compilerOptions: {
      target: 'es5'
    }
  }
}

[resir014]

@Cammisuli Please update gatsby-plugin-typescript. This whole issue is fixed on #3369, so the workaround is no longer needed.