anephenix/hub

/*
    Validators
    ----------

    This is a collection of utility functions that help prevent the developer
    from providing invalid configuration settings when using the library.

*/

// Checks if a parameter passed is not an object
const isNotAnObject = (parameter) => {
    if (Array.isArray(parameter)) return true;
    return !(parameter instanceof Object);
};

const checkAreFunctions = ({ object, key }) => {
    const arrayItemTypes = [...new Set(object[key].map((x) => typeof x))];
    if (arrayItemTypes.length > 0 && arrayItemTypes !== ['function']) {
        throw new Error(`The array for key ${key} can only contain functions`);
    }
};

const checkKeyIsAnArrayOfFunctions = ({ object, key }) => {
    if (Array.isArray(object[key])) {
        if (object[key].length > 0) {
            checkAreFunctions({ object, key });
        }
    } else {
        throw new Error(`The ${key} key needs to be an array of functions`);
    }
};

const auditObject = (object, keys) => {
    for (const key of keys) {
        if (!object[key]) {
            object[key] = [];
        } else {
            checkKeyIsAnArrayOfFunctions({ object, key });
        }
    }
    return object;
};

// Ensures that the server event listeners passed are properly filled in with functions
const auditServerEventListeners = (serverEventListeners) => {
    if (!serverEventListeners) return null;
    if (isNotAnObject(serverEventListeners)) {
        throw new Error('serverEventListeners is not an object');
    }

    const keys = ['connection', 'listening', 'headers', 'close', 'error'];
    serverEventListeners = auditObject(serverEventListeners, keys);
    return serverEventListeners;
};

// Ensures that the connection event listeners passed are properly filled in with functions
const auditConnectionEventListeners = (connectionEventListeners) => {
    if (!connectionEventListeners) return null;
    if (isNotAnObject(connectionEventListeners)) {
        throw new Error('connectionEventListeners is not an object');
    }

    const keys = ['message', 'error', 'close'];
    connectionEventListeners = auditObject(connectionEventListeners, keys);
    return connectionEventListeners;
};

module.exports = { auditServerEventListeners, auditConnectionEventListeners };