assertsjs/src/Asserts.js

ECMA6 Module for Javascript type validations

'use strict';

class  Asserts {
    /**
     * @param {string} errorMessageArgument
     */
    static doAssertFailure(errorMessageArgument) {
        const errorMessage = errorMessageArgument || 'Assertion error';
        throw {
            message: errorMessage
        }
    }
    /**
     * @param {boolean} value
     * @param {string} errorMessageArgument
     */
    static assert(value, errorMessageArgument) {
        if (value) {
            return value;
        } else {
            this.doAssertFailure(errorMessageArgument);
        }
    }
    /**
    * @param {object} value
    * @param {string} errorMessageArgument
    */
    static assertObject(value, errorMessageArgument) {
        if (typeof value == 'object') {
            return value;
        } else {
            const errorMessage = errorMessageArgument || 'Assertion error: object must be provided';
            this.doAssertFailure(errorMessage);
        }
    }
    /**
     * @param {string} value
     * @param {string} errorMessageArgument
     */
    static assertString(value, errorMessageArgument) {
        if (typeof value == 'string') {
            return value;
        } else {
            const errorMessage = errorMessageArgument || 'Assertion error: string must be provided';
            this.doAssertFailure(errorMessage);
        }
    }
    /**
     * @param {function} value
     * @param {string} errorMessageArgument
     */
    static assertFunction(value, errorMessageArgument) {
        if (typeof value == 'function') {
            return value;
        } else {
            const errorMessage = errorMessageArgument || 'Assertion error: function must be provided';
            this.doAssertFailure(errorMessage);
        }
    }
    /**
     * @param {boolean} value
     * @param {string} errorMessageArgument
     */
    static assertBoolean(value, errorMessageArgument) {
        if (typeof value == 'boolean') {
            return value;
        } else {
            const errorMessage = errorMessageArgument || 'Assertion error: boolean must be provided';
            this.doAssertFailure(errorMessage);
        }
    }
    /**
     * @param {*} value His typeof result should equal type argument
     * @param {string} type
     * @param {string} errorMessageArgument
     */
    static assertType(value, type, errorMessageArgument) {
        this.assertString(type, 'Assertion error: Type must be an string');
        if (typeof value === type) {
            return value;
        } else {
            const errorMessage = errorMessageArgument || 'Assertion error: ' + type + ' must be provided';
            this.doAssertFailure(errorMessage);
        }
    }
    /**
     * @param {string} errorMessageArgument
     */
    static fail(errorMessageArgument) {
        this.doAssertFailure(errorMessageArgument);
    }
}

module.exports = Asserts;