evl/dist/index.js

Function fallback when error.

"use strict";
/**
 * Call the main function and return value when successfully call.
 * Otherwise, call and return value from the fallback function (or value).
 *
 * (`null` will be return when both functions are unsuccessfully called.)
 *
 * @exports
 * @template A1 Arguments of the main function
 * @template A2 Arguments of the fallback function
 * @template R1 Value of the main function
 * @template R2 Value of the fallback function
 * @param {(((...args1: A1) => R1) | R1)} mainFunction Main function or value
 * @param {(((...args2: A2) => R2) | R2)} fallbackFunction Fallback function or value
 * @returns A function that return value from either of given functions
 */
function evl(mainFunction, fallbackFunction) {
    /**
     * Invoke either of given functions with given arguments.
     *
     * @param {A1} [mainArgs=[]] Arguments of `mainFunction`
     * @param {A2} [fallbackArgs=[]] Arguments of `fallbackFunction`
     * @returns A value from either of `mainFunction` or `fallbackFunction`
     */
    var invoke = function (mainArgs, fallbackArgs) {
        if (mainArgs === void 0) { mainArgs = []; }
        if (fallbackArgs === void 0) { fallbackArgs = []; }
        try {
            if (typeof mainFunction !== 'function') {
                return mainFunction;
            }
            return mainFunction.apply(void 0, mainArgs);
        }
        catch (_) {
            if (typeof fallbackFunction !== 'function') {
                return fallbackFunction;
            }
            try {
                return fallbackFunction.apply(void 0, fallbackArgs);
            }
            catch (_) {
                return null;
            }
        }
    };
    return invoke;
}
module.exports = evl;