improve TypeError messages

by using append-type

https://github.com/shinnn/append-type

index.js

@@ -1,16 +1,19 @@
 'use strict';
 
+var appendType = require('append-type');
+
 /*!
  * indexed-filter | MIT (c) Shinnosuke Watanabe
  * https://github.com/shinnn/indexed-filter
 */
+
 function indexedFilter(arr, fn, thisObj) {
 	if (!Array.isArray(arr)) {
-		throw new TypeError(String(arr) + ' is not an array. Expected an array to be filtered.');
+		throw new TypeError('Expected an array to be filtered, but got a non-array value ' + appendType(arr) + '.');
 	}
 
 	if (typeof fn !== 'function') {
-		throw new TypeError(String(fn) + ' is not a function. Expected a filter function that returns Boolean value.');
+		throw new TypeError('Expected a filter function, but got a non-function value ' + appendType(fn) + '.');
 	}
 
 	var results = [];

index.mjs

@@ -2,13 +2,15 @@
  * indexed-filter | MIT (c) Shinnosuke Watanabe
  * https://github.com/shinnn/indexed-filter
 */
+import appendType from 'append-type';
+
 export default function indexedFilter(arr, fn, thisObj) {
 	if (!Array.isArray(arr)) {
-		throw new TypeError(String(arr) + ' is not an array. Expected an array to be filtered.');
+		throw new TypeError('Expected an array to be filtered, but got a non-array value ' + appendType(arr) + '.');
 	}
 
 	if (typeof fn !== 'function') {
-		throw new TypeError(String(fn) + ' is not a function. Expected a filter function that returns Boolean value.');
+		throw new TypeError('Expected a filter function, but got a non-function value ' + appendType(fn) + '.');
 	}
 
 	var results = [];

package.json

@@ -28,6 +28,9 @@
 		"client-side",
 		"browser"
 	],
+	"dependencies": {
+		"append-type": "^1.0.1"
+	},
 	"devDependencies": {
 		"@shinnn/eslint-config": "^5.4.0",
 		"eslint": "^4.19.1",

test.js

@@ -20,14 +20,14 @@ test('indexedFilter()', t => {
 
 	t.throws(
 		() => indexedFilter(1, () => {}),
-		/TypeError.*1 is not an array\. Expected an array to be filtered\./,
-		'should have a function name.'
+		/TypeError.*Expected an array to be filtered, but got a non-array value 1 \(number\)\./,
+		'should invalidate a non-array first argument.'
 	);
 
 	t.throws(
 		() => indexedFilter([], 1),
-		/TypeError.*1 is not a function\. Expected a filter function that returns Boolean value\./,
-		'should hadsfdfdfve a function name.'
+		/TypeError.*Expected a filter function, but got a non-function value 1 \(number\)\./,
+		'should invalidate a non-function second argument.'
 	);
 
 	t.end();