Write Jest tests for the get method:
class Users {
/** {string: number} database of users and counts **/
static users = {};
/**
* Add a user and associated count to the database.
* @param {string} userName - name of user to add.
* @throws Error if userName is already in database.
*/
static add(userName, count) {
if (!this.users.hasOwnProperty(userName)) {
this.users[userName] = count;
} else {
throw Error(`${userName} already exists`);
}
}
/**
* Remove a user from the database.
* @param {string} userName - name of user to remove.
* @throws Error if userName is not in database.
*/
static remove(userName) {
if (this.users.hasOwnProperty(userName)) {
delete this.users[userName];
} else {
throw Error(`${userName} does not exist`);
}
}
/**
* Get a user's count.
* @param {string} userName - user's name.
* @return {number} The user's count.
*/
static get(userName) {
return new Promise((resolve, reject) => {
setTimeout(() => {
if (this.users.hasOwnProperty(userName)) {
resolve(this.users[userName]);
} else {
reject(`${userName} does not exist`);
}
}, 100);
});
}
}
module.exports = Users;