Vite, loadEnv, process.env[VARS] in the vite.config

load-process-env.ts

/*
loadProcessEnv function is setting process.env vars accessible in the vite.config and parse process.env vars.
(string process.env.FLAG="true" => boolean process.env.FLAG=true)
*/

// @file: .env

VITE_NEED_MINIFY=true

// @file: load-process-env.ts

import {loadEnv} from 'vite';

function parseEnvironmentVariable(variable: string) {
  try {
    return JSON.parse(variable);
  } catch (err) {
    return variable.toString();
  }
}

export function loadProcessEnv(mode: string, evnsFolder: string = 'ABSOLUTE PATH TO FOLDER WHERE ENVS IS') {
  // It makes the process.env.PROD/ENV for the web-tooling context (like import.meta.env.PROD/ENV)
  process.env.PROD = process.env.NODE_ENV === 'production' ? 'true' : 'false';
  process.env.DEV = process.env.NODE_ENV === 'development' ? 'true' : 'false';

  process.env = {
    ...process.env,

    ...Object.entries(loadEnv(mode, evnsFolder)).reduce((acc, [key, value]) => ({
      ...acc,
      [key]: parseEnvironmentVariable(value),
    }), {}),
  };
}

// @file: vite.config.ts

import {defineConfig} from 'vite';
import * as PATHS from './paths';
import {loadProcessEnv} from './load-process-env';

export default defineConfig(({mode}) => {
  loadProcessEnv(mode, PATHS.PROJECT_ROOT);

  return {
    // ...
    build: {
      // Boolean(true|false) instead of Boolean("true"|"false")
      minify: Boolean(process.env.VITE_NEED_MINIFY) ?? 'esbuild',
    },    
    // ...
  };
});