Ensure that we're always dealing with a string

index.js

@@ -2,6 +2,7 @@
 
 const url = require("url");
 const ValidationError = require("@validatem/error");
+const isString = require("@validatem/is-string");
 
 module.exports = function (protocols) {
 	if (protocols != null && !Array.isArray(protocols)) {
@@ -12,23 +13,26 @@ module.exports = function (protocols) {
 		? new Set(protocols.map((protocol) => protocol.toLowerCase()))
 		: null;
 
-	return function isURL(value) {
-		let parsed = url.parse(value);
+	return [
+		isString,
+		function isURL(value) {
+			let parsed = url.parse(value);
 
-		let parsedProtocol = (parsed.protocol != null)
-			? parsed.protocol.replace(/:$/, "")
-			: null;
+			let parsedProtocol = (parsed.protocol != null)
+				? parsed.protocol.replace(/:$/, "")
+				: null;
 
-		if (parsedProtocol == null) {
-			return new ValidationError("Must be a valid URL");
-		} else if (protocolSet != null && !protocolSet.has(parsedProtocol.toLowerCase())) {
-			let validProtocolList = protocols
-				.map((protocol) => protocol.toUpperCase())
-				.join(", ");
+			if (parsedProtocol == null) {
+				return new ValidationError("Must be a valid URL");
+			} else if (protocolSet != null && !protocolSet.has(parsedProtocol.toLowerCase())) {
+				let validProtocolList = protocols
+					.map((protocol) => protocol.toUpperCase())
+					.join(", ");
 
-			return new ValidationError(`Must be a URL with one of the following protocols: ${validProtocolList} - but got ${parsedProtocol.toUpperCase()} instead`);
-		} else {
-			return parsed;
+				return new ValidationError(`Must be a URL with one of the following protocols: ${validProtocolList} - but got ${parsedProtocol.toUpperCase()} instead`);
+			} else {
+				return parsed;
+			}
 		}
-	}
+	];
 };

package.json

@@ -11,7 +11,8 @@
   "author": "Sven Slootweg <admin@cryto.net>",
   "license": "WTFPL OR CC0-1.0",
   "dependencies": {
-    "@validatem/error": "^1.0.0"
+    "@validatem/error": "^1.0.0",
+    "@validatem/is-string": "^0.1.1"
   },
   "devDependencies": {
     "@validatem/core": "^0.3.1"

yarn.lock

@@ -80,6 +80,14 @@
     "@validatem/error" "^1.0.0"
     is-plain-obj "^2.1.0"
 
+"@validatem/is-string@^0.1.1":
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/@validatem/is-string/-/is-string-0.1.1.tgz#0710d8cebedd4d6861b4a8c63d7803ed6d2f9d6c"
+  integrity sha512-iyRVYRPgRt2ZlWyc7pzN1WkO6apzE8at39XQa4WUr8qRPfJn12V4khS9MumWbZs8N2qqajrxMigB2LJUCKOCRg==
+  dependencies:
+    "@validatem/error" "^1.0.0"
+    is-string "^1.0.5"
+
 "@validatem/match-special@^0.1.0":
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/@validatem/match-special/-/match-special-0.1.0.tgz#4e0c28f1aee5bf53c1ef30bbf8c755d4946ae0ff"
@@ -208,6 +216,11 @@ is-regexp@^2.0.0:
   resolved "https://registry.yarnpkg.com/is-regexp/-/is-regexp-2.1.0.tgz#cd734a56864e23b956bf4e7c66c396a4c0b22c2d"
   integrity sha512-OZ4IlER3zmRIoB9AqNhEggVxqIH4ofDns5nRrPS6yQxXE1TPCUpFznBfRQmQa8uC+pXqjMnukiJBxCisIxiLGA==
 
+is-string@^1.0.5:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/is-string/-/is-string-1.0.5.tgz#40493ed198ef3ff477b8c7f92f644ec82a5cd3a6"
+  integrity sha512-buY6VNRjhQMiF1qWDouloZlQbRhDPCebwxSjxMjxgemYT46YMd2NR0/H+fBhEfWX4A/w9TBJ+ol+okqJKFE6vQ==
+
 supports-color@^7.1.0:
   version "7.1.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-7.1.0.tgz#68e32591df73e25ad1c4b49108a2ec507962bfd1"