guardz/dist/typeguards/isNumeric.js

A simple and lightweight TypeScript type guard library for runtime type validation.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.isNumeric = void 0;
const generateTypeGuardError_1 = require("./generateTypeGuardError");
/**
 * Checks if a value is numeric (a number or a string that can be converted to a number).
 *
 * This type guard validates that a value is either a number or a string that can be
 * converted to a number. This is useful for validating numeric values in various contexts
 * like form inputs, API data, object keys, etc.
 *
 * @param value - The value to check
 * @param config - Optional configuration for error handling
 * @returns True if the value is a number or a string that can be converted to a number, false otherwise
 *
 * @example
 * ```typescript
 * import { isNumeric } from 'guardz';
 *
 * console.log(isNumeric(1)); // true
 * console.log(isNumeric("1")); // true
 * console.log(isNumeric("123")); // true
 * console.log(isNumeric("abc")); // false
 * console.log(isNumeric("1.5")); // true
 * console.log(isNumeric("1.0")); // true
 * console.log(isNumeric("0")); // true
 * console.log(isNumeric("")); // false
 * console.log(isNumeric(null)); // false
 * console.log(isNumeric(undefined)); // false
 *
 * // With type narrowing
 * const data: unknown = getDataFromAPI();
 * if (isNumeric(data)) {
 *   // data is now typed as Numeric
 *   console.log(Number(data)); // Safe to convert
 * }
 * ```
 */
const isNumeric = function (value, config) {
    // Check if it's already a number
    if (typeof value === 'number') {
        // Reject NaN
        if (!isNaN(value)) {
            return true;
        }
        else {
            if (config) {
                config.callbackOnError((0, generateTypeGuardError_1.generateTypeGuardError)(value, config.identifier, 'number key'));
            }
            return false;
        }
    }
    // Check if it's a string that can be converted to a number
    if (typeof value === 'string') {
        // Handle edge cases
        if (value === '' || value === ' ' || value === 'NaN' || value === '+0') {
            if (config) {
                config.callbackOnError((0, generateTypeGuardError_1.generateTypeGuardError)(value, config.identifier, 'number key'));
            }
            return false;
        }
        const num = Number(value);
        // Check if it's a valid number (not NaN)
        if (!isNaN(num)) {
            return true;
        }
        else {
            if (config) {
                config.callbackOnError((0, generateTypeGuardError_1.generateTypeGuardError)(value, config.identifier, 'number key'));
            }
            return false;
        }
    }
    // Not a valid number key
    if (config) {
        config.callbackOnError((0, generateTypeGuardError_1.generateTypeGuardError)(value, config.identifier, 'number key'));
    }
    return false;
};
exports.isNumeric = isNumeric;