fix(server-side): use environment I18NEXT_DEFAULT_CONFIG_PATH to ch…

…ange the default config path (#2089)

README.md

@@ -329,7 +329,6 @@ For example, if you want to use `{` and `}` the config would look like this:
 }
 ```
 
-<!-- 
 #### Custom `next-i18next.config.js` path
 
 If you want to change the default config path, you can set the environment variable `I18NEXT_DEFAULT_CONFIG_PATH`.
@@ -357,7 +356,8 @@ module.exports = {
 ```
 
 This means that the i18n configuration file will be in the same directory as `next.config.js` and it doesn't matter where your current working directory is. This helps for example for `nx` when you have monorepo and start your application from project root but the application is in `apps/{appName}`.
--->
+
+**Notice** If your config `next-i18next.config.js` is not in the same directory as `next.config.js`, you must copy it manually (or by custom script).
 
 ## Notes
 

src/serverSideTranslations.ts

@@ -9,7 +9,17 @@ import { globalI18n } from './appWithTranslation'
 import { UserConfig, SSRConfig } from './types'
 import { getFallbackForLng, unique } from './utils'
 
-const DEFAULT_CONFIG_PATH = './next-i18next.config.js'
+let DEFAULT_CONFIG_PATH = './next-i18next.config.js'
+
+/**
+ * One line expression like `const { I18NEXT_DEFAULT_CONFIG_PATH: DEFAULT_CONFIG_PATH = './next-i18next.config.js' } = process.env;`
+ * is breaking the build, so keep it like this.
+ *
+ * @see https://github.com/i18next/next-i18next/pull/2084#issuecomment-1420511358
+ */
+if (process.env.I18NEXT_DEFAULT_CONFIG_PATH) {
+  DEFAULT_CONFIG_PATH = process.env.I18NEXT_DEFAULT_CONFIG_PATH
+}
 
 export const serverSideTranslations = async (
   initialLocale: string,
@@ -24,7 +34,6 @@ export const serverSideTranslations = async (
   }
 
   let userConfig = configOverride
-  // const configPath = path.resolve(process.env.I18NEXT_DEFAULT_CONFIG_PATH || DEFAULT_CONFIG_PATH)
   const configPath = path.resolve(DEFAULT_CONFIG_PATH)
 
   if (