respress/libs/resp-args-parser.js

A RESP 'Redis Serialization Protocol' library implementation to generate a server, uses a similar approach to express to define you serer, making it easy and fast.

const yargs = require('yargs');
let stringArgv = require('string-argv').parseArgsStringToArgv;
let debug = require('debug')('RESP-SERVER');

/**
 * Used to parse the arguments in commands and also register commands.
 * @private
 */
class RESP_ARGS_PARSER {
    /**
     * Create and instance of RESP_ARGS_PARSER
     */
    constructor() {
        this.cmdCallbacks = {};
        this.yargs = yargs();
        this.commandList = [];
        debug("Created the RESP Argument Parser.")
        this.yargs
            .exitProcess(false)
            .showHelpOnFail(false,"")
    }

    /**
     * Adds a command that will be used by the server to execute 
     * @param {String} commandString The command definition 
     * @param {function} cb The callback used for the command when executed 
     */
    addCommand(commandString, cb) {
        let split = stringArgv(commandString)
        split[0] = split[0].toLowerCase();
        this.cmdCallbacks[split[0]] = cb;
        this.yargs.command(split.join(" "));
        this.commandList.push(split.join(" "));
        debug(`Command ${commandString} added to RESP Arg Parser.`)
    }

    /**
     * Parses the command sent by the client based on the added command. The parse tags each positional argument.
     * @param {String} reqCommand The command to be parsed for the client.
     * @returns Parsed command that can be used eventually making its way to the req argument.
     */
    parse(reqCommand) {
        reqCommand[0] = reqCommand[0].toLowerCase();
        let result = this.yargs.parse(reqCommand);
        debug(`Parsing ${reqCommand} generated ${result}`)
        return result;
    }


}
module.exports = new RESP_ARGS_PARSER();