react-native-onesignal/src/helpers.js

React Native OneSignal SDK

import invariant from 'invariant';
import {
    PERMISSION_CHANGED,
    SUBSCRIPTION_CHANGED,
    EMAIL_SUBSCRIPTION_CHANGED
} from './events';

export function isValidCallback(handler) {
    invariant(
        typeof handler === 'function',
        'Must provide a valid callback'
    );
}

export function checkIfInitialized(object) {
    const initialized = object != null;
    return initialized;
}

/**
 * Returns whether the handler associated with the event name can have multiple instances set
 * @param  {String} eventName
 */
export function isMultipleInstancesPossible(eventName) {
    switch(eventName){
        case PERMISSION_CHANGED:
        case SUBSCRIPTION_CHANGED:
        case EMAIL_SUBSCRIPTION_CHANGED:
            return true;
        default:
            return false;
    }
}