fix: Do not rewrite actual URLs that start with http://, https:// or …

…just //

Prior to this commit, an actual URL starting with a protocol like`https://` would have been rewritten to `./https://` which is clearly undesired. Although webpack can't resolve remote module requests anyway (those starting with http:// and such) and thus will throw an error, it is still correct to leave these kind of URLs untouched by the loader-utils.

Related discussion: #79

lib/urlToRequest.js

@@ -35,6 +35,9 @@ function urlToRequest(url, root) {
 			default:
 				throw new Error("Unexpected parameters to loader-utils 'urlToRequest': url = " + url + ", root = " + root + ".");
 		}
+	} else if(/^(?:https?:)?\/\//.test(url)) {
+		// Preserve http and https urls
+		request = url;
 	} else if(/^\.\.?\//.test(url)) {
 		// A relative url stays
 		request = url;

test/urlToRequest.test.js

@@ -13,6 +13,9 @@ ExpectedError.prototype.matches = function(err) {
 describe("urlToRequest()", () => {
 	[
 		// without root
+		[["//google.com"], "//google.com", "should handle scheme-agnostic urls"],
+		[["http://google.com"], "http://google.com", "should handle http urls"],
+		[["https://google.com"], "https://google.com", "should handle https urls"],
 		[["path/to/thing"], "./path/to/thing", "should handle implicit relative urls"],
 		[["./path/to/thing"], "./path/to/thing", "should handle explicit relative urls"],
 		[["~path/to/thing"], "path/to/thing", "should handle module urls (with ~)"],