`imageSizes` are ignored if they are in a conditional `process.env.NODE_ENV === "production"`

[Tim Krämer]

Hi,

I've noticed that conditional config parameters are ignored and default were used.

For example, this one with changed imageSizes will work as expected

next.config.js:

module.exports = {
  images: {
    loader: "custom",
    imageSizes: [16, 48, 54, 64, 100, 128, 144, 384],
    deviceSizes: [640, 750, 828, 1080, 1200, 1920],
  },
  env: {
    // ...
  },
}

but having a conditional in there, will ignore the changes and load the defaults:

module.exports = {
 images:
    process.env.NODE_ENV === "production"
      ? {
          loader: "custom",
          imageSizes: [16, 48, 54, 64, 100, 128, 144, 384],
          deviceSizes: [640, 750, 828, 1080, 1200, 1920],
        }
      : { 
         // ...
        },
  env: {
    // ...
  },
}

I think it might be helpful to output a warning when the process isn't finding the values, so that one can see it will use defaults (like it warns when it doesn't find a next.config.js)

[Niels]

Hi @TimKraemer,

Thanks for the bug report. I now switched to the same method that Next.js uses to parse the next.config.js. Your bug should be fixed now in v1.0.1. Please give it a try.

[Tim Krämer]

works perfectly!