validate.js (1476B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var isPositive = require( '@stdlib/assert/is-positive-number' ).isPrimitive; 24 var isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive; 25 26 27 // MAIN // 28 29 /** 30 * Validates parameters. 31 * 32 * @private 33 * @param {PositiveInteger} k - shape parameter 34 * @param {PositiveNumber} lambda - rate parameter 35 * @returns {(Error|null)} error or null 36 * 37 * @example 38 * var err = validate( 1, 2.5 ); 39 * if ( err ) { 40 * throw err; 41 * } 42 */ 43 function validate( k, lambda ) { 44 if ( !isPositiveInteger( k ) ) { 45 return new TypeError( 'invalid argument. First argument must be a positive integer. Value: `' + k + '`.' ); 46 } 47 if ( !isPositive( lambda ) ) { 48 return new TypeError( 'invalid argument. Second argument must be a positive number. Value: `' + lambda + '`.' ); 49 } 50 return null; 51 } 52 53 54 // EXPORTS // 55 56 module.exports = validate;