01. Request Validator

function validateRequest(obj) {

    let method =obj.method;
    if(!(method==='GET'||method==='POST'||method==='DELETE'||method==='CONNECT')){
        throw new Error('Invalid request header: Invalid Method');
    }

    if(obj.uri!==undefined){
        let pattern =/([a-z ]+)?\.+[a-z0-9 ]+/;
        let match =obj.uri.match(pattern);
        if(!(match || obj.uri==='*')){
            throw new Error ('Invalid request header: Invalid URI');
        }
    }
    else if(obj.uri===undefined){
        throw new Error ('Invalid request header: Invalid URI');
    }


    let versionArr=['HTTP/0.9', 'HTTP/1.0', 'HTTP/1.1', 'HTTP/2.0' ];
    let versionResult=versionArr.includes(obj.version);
    if(!versionResult) {
        throw new Error ('Invalid request header: Invalid Version');
    }

    if(obj.message){
        let message =obj.message.match(/^[^\<\>\\\&\'\"]+$/);
        if(!(message || obj.message==='')){
            throw new Error ('Invalid request header: Invalid Message');
        }
    }
    else if(obj.message===undefined){
        throw new Error ('Invalid request header: Invalid Message');
    }

    return obj;
}