AppConfig 

  type AppConfigItem = {
    [key: string]: string;
}

function checkMissingEnvs(requiredEnv: AppConfigItem) {
    let missingEnvs: string[] = []
    for (const key in requiredEnv) {
        const value = requiredEnv[key]
        if (value === '') {
            missingEnvs.push(key)
        }
    }
    if (missingEnvs.length > 0) {
        throw new Error(`Missing required envs: ${missingEnvs}`)
    }
}

function ServerAppConfig() {
    const requiredEnv: AppConfigItem = {}
    const optionalEnv: AppConfigItem = {}

    checkMissingEnvs(requiredEnv)

    return {
        ...requiredEnv,
        ...optionalEnv,
    };
}

function ClientAppConfig() {
    const requiredEnv: AppConfigItem = {
        NEXT_PUBLIC_VAR: process.env.NEXT_PUBLIC_VAR || '',
    }
    const optionalEnv: AppConfigItem = {}

    checkMissingEnvs(requiredEnv)

    return {
        ...requiredEnv,
        ...optionalEnv,
    };
}


export {ServerAppConfig, ClientAppConfig}
## AppConfig

Static Exporting

Common error I’ll get when doing static builds with nextjs

  Page "/blog/[blog]" is missing "generateStaticParams()" so it cannot be used with "output: export" config.

Make absolutely sure the directory structure (say /app/blog/[blog]/page.tsx) lines up with the getStaticParams. In this case, don’t use id but use blog because of the [blog]. If it was [id] you would use id