node-redis/packages/client/lib/commands/CLIENT_TRACKING.ts

import { RedisCommandArgument, RedisCommandArguments } from '.';

interface CommonOptions {
    REDIRECT?: number;
    NOLOOP?: boolean;
}

interface BroadcastOptions {
    BCAST?: boolean;
    PREFIX?: RedisCommandArgument | Array<RedisCommandArgument>;
}

interface OptInOptions {
    OPTIN?: boolean;
}

interface OptOutOptions {
    OPTOUT?: boolean;
}

type ClientTrackingOptions = CommonOptions & (
    BroadcastOptions |
    OptInOptions |
    OptOutOptions
);

export function transformArguments<M extends boolean>(
    mode: M,
    options?: M extends true ? ClientTrackingOptions : undefined
): RedisCommandArguments {
    const args: RedisCommandArguments = [
        'CLIENT',
        'TRACKING',
        mode ? 'ON' : 'OFF'
    ];

    if (mode) {
        if (options?.REDIRECT) {
            args.push(
                'REDIRECT',
                options.REDIRECT.toString()
            );
        }

        if (isBroadcast(options)) {
            args.push('BCAST');

            if (options?.PREFIX) {
                if (Array.isArray(options.PREFIX)) {
                    for (const prefix of options.PREFIX) {
                        args.push('PREFIX', prefix);
                    }
                } else {
                    args.push('PREFIX', options.PREFIX);
                }
            }
        } else if (isOptIn(options)) {
            args.push('OPTIN');
        } else if (isOptOut(options)) {
            args.push('OPTOUT');
        }

        if (options?.NOLOOP) {
            args.push('NOLOOP');
        }
    }

    return args;
}

function isBroadcast(options?: ClientTrackingOptions): options is BroadcastOptions {
    return (options as BroadcastOptions)?.BCAST === true;
}

function isOptIn(options?: ClientTrackingOptions): options is OptInOptions {
    return (options as OptInOptions)?.OPTIN === true;
}

function isOptOut(options?: ClientTrackingOptions): options is OptOutOptions {
    return (options as OptOutOptions)?.OPTOUT === true;
}

export declare function transformReply(): 'OK' | Buffer;