fix: handle non-empty string request (fixes #12)

Author: gajus

lib/join.js

@@ -4,11 +4,11 @@ var absoluteWinRegExp = /^[A-Z]:([\\\/]|$)/i;
 var absoluteNixRegExp = /^\//i;
 
 module.exports = function join(path, request) {
-	if(request == "") return normalize(path);
+	if(!request) return normalize(path);
 	if(absoluteWinRegExp.test(request)) return normalize(request.replace(/\//g, "\\"));
 	if(absoluteNixRegExp.test(request)) return normalize(request);
 	if(path == "/") return normalize(path + request);
 	if(absoluteWinRegExp.test(path)) return normalize(path.replace(/\//g, "\\") + "\\" + request.replace(/\//g, "\\"));
 	if(absoluteNixRegExp.test(path)) return normalize(path + "/" + request);
 	return normalize(path + "/" + request);
-};
+};

test/MemoryFileSystem.js

@@ -352,6 +352,8 @@ describe("join", function() {
 	it("should join paths (weird cases)", function() {
 		var fs = new MemoryFileSystem();
 		fs.join("/", "").should.be.eql("/");
+		// https://github.com/webpack/memory-fs/pull/17
+		fs.join("/", undefined).should.be.eql("/");
 		fs.join("/a/b/", "").should.be.eql("/a/b/");
 		fs.join("/a/b/c", "").should.be.eql("/a/b/c");
 		fs.join("C:", "").should.be.eql("C:");