fix: allow Windows unc paths to be resolved and normalized (#1351)

* Add unc paths to isAbsolute regex

* Allow unc paths to be resolved and normalized

* Remove trailing whitespace

Author: TomWilloughby

lib/path/index.js

@@ -14,7 +14,7 @@ var isAbsolute =
  * @returns {boolean} `true` if path is absolute
  */
 path.isAbsolute = function isAbsolute(path) {
-    return /^(?:\/|\w+:)/.test(path);
+    return /^(?:\/|\w+:|\\\\\w+)/.test(path);
 };
 
 var normalize =
@@ -24,6 +24,13 @@ var normalize =
  * @returns {string} Normalized path
  */
 path.normalize = function normalize(path) {
+    var firstTwoCharacters = path.substring(0,2);
+    var uncPrefix = "";
+    if (firstTwoCharacters === "\\\\") {
+        uncPrefix = firstTwoCharacters;
+        path = path.substring(2);
+    }
+
     path = path.replace(/\\/g, "/")
                .replace(/\/{2,}/g, "/");
     var parts    = path.split("/"),
@@ -44,7 +51,7 @@ path.normalize = function normalize(path) {
         else
             ++i;
     }
-    return prefix + parts.join("/");
+    return uncPrefix + prefix + parts.join("/");
 };
 
 /**

lib/path/tests/index.js

@@ -10,6 +10,8 @@ tape.test("path", function(test) {
     test.notOk(path.isAbsolute("some\\path\\file.js"), "should identify relative windows paths");
     test.notOk(path.isAbsolute("some/path/file.js"), "should identify relative unix paths");
 
+    test.ok(path.isAbsolute("\\\\some-unc\\path\\file.js"), "should identify windows unc paths");
+
     var paths = [
         {
             actual: "X:\\some\\..\\.\\path\\\\file.js",
@@ -45,6 +47,20 @@ tape.test("path", function(test) {
         }, {
             actual: "/.././path//file.js",
             normal: "/path/file.js"
+        }, {
+            actual: "\\\\some-unc\\path\\file.js",
+            normal: "\\\\some-unc/path/file.js",
+            resolve: {
+                origin: "\\\\some-unc\\path\\origin.js",
+                expected: "\\\\some-unc/path/file.js"
+            }
+        }, {
+            actual: "\\\\some-unc\\path\\..\\file.js",
+            normal: "\\\\some-unc/file.js",
+            resolve: {
+                origin: "\\\\some-unc\\path\\..\\origin.js",
+                expected: "\\\\some-unc/file.js"
+            }
         }
     ];