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reactjsnext.js

nextjs - next build with NODE_ENV=development

I'd like to build my nextjs project as development mode.

and I tried like it

package.json

{
  ...
  "scripts": {
    "dev": "next",
    "build:dev": "set NODE_ENV=development & next build",
    "build:prod": "set NODE_ENV=production & next build",
    "start:dev": "set NODE_ENV=development & next start",
    "start:prod": "set NODE_ENV=production & next start"
  }
  ...
}

next.config.js

module.exports = withSass({
  env: {
    baseUrl: process.env.NODE_ENV === "development" ? "devServerURL": "prodServerURL"
  }
});

but I couldn't achieve what I want.

so, I tried with some change.

package.json

  "scripts": {
    "dev": "next",
    "build": "next build",
    "start:dev": "set NODE_ENV=development & next start",
    "start:prod": "set NODE_ENV=production & next start"
  }

but it also doesn't work.

How can I build the next with development mode?

Thanks in advance.

EDIT

My OS is Windows 10.

Solution

  • UPDATE 2022-11-23:

    See how-to-set-environment-variables-from-within-package-json.

    In short:
    "start:dev": "NODE_ENV=development next start"

    You might need cross-env (on Windows ? I don't know):
    "start:dev": "cross-env NODE_ENV=development next start"

    More specific documentation is now available (and maybe requirements also have changed, or maybe not):

    environment-variable-load-order:

    ... Note: The allowed values for NODE_ENV are production, development and test.

    non-standard-node-env:

    ... only permitting three (3) values:

    • production: When your application is built with next build
    • development: When your application is ran with next dev
    • test: When your application is being tested (e.g. jest)

    ORIGINAL ANSWER:

    See issue #9123, (Oct 18, 2019) :

    NODE_ENV is a reserved environment variable that cannot be changed. The only valid values are production, development, and test.

    If you need your app behavior to change in different production environments, please use a different variable like APP_ENV.

    And issues #17032 (Sep 12, 2020):

    process.env.NODE_ENV only has 2 possible values development and production. If this is not set to that value you'll run into all kinds of library edge cases (especially in node_modules) where you get severely de-optimized results. E.g. if you run a performance test you'll get significantly worse results if process.env.NODE_ENV is not set to production