I'm writing a simple server in vanilla JavaScript and Node.js. I made a database.js file which contains abstractions to interact with my database (redis).
I want to automatically set n_users and n_rooms if they are not yet found in the database. To do so, I have the following lines in database.js:
//set n_users if never set in redis
if (await getKey("n_users") == null){
setKey("n_users", 0);
}
//set n_rooms if never set in redis
if (await getKey("n_rooms") == null){
setKey("n_rooms", 0);
}
This code works as expected when I open a node session and then type .load database.js. However, the code does not work when directly calling node database.js from the terminal:
/Users/.../database.js:29
if (await getKey("n_users") == null){
^^^^^^
SyntaxError: Unexpected identifier
I expected javascript files to work similarly to python files, in the sense that the entirety of a python file gets interpreted when called (or imported). I can't find any information on how exactly node handles its input files to correct what I'm doing wrong.
Ultimately, I want to be able to automatically execute the above lines of code when running node server.js from a terminal, where server.js requires an object from database.js. What is the best way to acomplish this?
Edit
Here's my database.jsfile:
let User = require('./shared/user').User;
let Room = require('./shared/room').Room;
const md5 = require('./stack_md5').MD5;
const redis = require('redis');
const salt = require('./salt').salt;
var prefix = "JS2023:";
const client = redis.createClient();
client.connect();
//should be map of token to user_id
let TOKENS = {};
async function getKey(key) {
return await client.get(`${prefix}${key}`);
}
async function setKey(key, value){
await client.set(`${prefix}${key}`, value);
}
async function delKey(key){
await client.del(`${prefix}${key}`);
}
//set n_users if never set in redis
if (await getKey("n_users") == null){
setKey("n_users", 0);
}
//set n_rooms if never set in redis
if (await getKey("n_rooms") == null){
setKey("n_rooms", 0);
}
//using local objects because mongodb doesnt work dont know why
const DB = {
//user should have at least username and password
//automatically md5's the password
//TODO refactor for clarity
create_user: async function(user_data){
//username must be unique
console.log(`user data: ${user_data}`);
if (await DB.get_user_id_by_username(user_data.username) != undefined) return Promise.reject("Username is already taken!");
let user_id = parseInt(await getKey(`n_users`));
let username = user_data.username;
let user_salt = salt(16);
let password = md5(user_data.password + user_salt);
let user = new User({id: user_id, username: username, password: password, salt: user_salt});
let user_string = JSON.stringify(user);
setKey(username, user_id)
.then(DB.set_user_by_id(user_id, user_string))
.then(setKey("n_users", user_id + 1));
return user_id;
},
get_room_by_id: async function (id){
},
set_room_by_id: async function (id, room_string){
},
//TODO this returns undefined rn
get_user_by_id: async function (id) {
//access DB
//clean data
//call callback with data
return await getKey(id);
}, //TODO enforce unique usernames
set_user_by_id: async function (id, user_string) {
await setKey(id, user_string);
}, //id should be unique
get_user_id_by_username: async function (username) {
return await getKey(username);
}, //verify password is correct and return cool access token
authenticate: async function (user_id, password) {
let user = JSON.parse(await getKey(user_id));
if (user.password !== md5(password + user.salt)) return Promise.reject("Wrong password!");
//is user already is online, he is in tokens. will not be authenticated
for (token in TOKENS) {
if (TOKENS[token] === user_id) return Promise.reject("User is already connected!");
}
var user_token = await DB.token(32);
//check that token is unique and if not create a new one and hope it is
while (user_token in TOKENS) user_token = await DB.token(32);
TOKENS[user_token] = user_id;
console.log(`generated token for ${user_id}: ${user_token}`)
return user_token;
},
//update_obj an object with the fields to update {username, password, whatever else except id and salt}
update_user: async function (id, update_obj) {
DB.get_user_by_id(id)
.then(function (user) {
for (let field in update_obj) {
switch (field) {
//password stored as its hash
case "password":
//salt is stored by user
user[field] = md5(update_obj[field] + user.salt);
break;
//id is only given by the server and cannot be modified
case "id":
continue;
case "salt":
continue;
//update inverse key-value in redis db
case "username":
delKey(`${user[field]}`)
.then(setKey(`${id}`, update_obj[field]));
break;
default:
user[field] = update_obj[field];
}
}
return user;
}).then(user => DB.set_user_by_id(id, JSON.stringify(user)));
},
//make a random token of given length
token: function (length) {
return salt(length);
},
// delete token associated with user_id (i.e, user no longer online)
revoke: async function (user_id) {
for (token in TOKENS) {
if (TOKENS[token] == user_id) {
delete (TOKENS[token]);
console.log(`${token} revoked, user ${user_id} is no longer online.`);
}
}
//for chaining promises
return user_id;
}, // this doesn't need to be async since tokens have to be dynamically maintained
/**
* check if token string is in tokens map
* @param token
* @returns {boolean}
*/
present: function (token) {
for (let stored_token in TOKENS) {
if (token === stored_token) {
return true;
}
}
return false;
},
}
module.exports = {DB, TOKENS};
