fixup! windows paths double slash, coverage

Author: wraithgar

lib/npa.js

@@ -66,6 +66,8 @@ function isFileSpec (spec) {
   if (isWindows) {
     return isWindowsFile.test(spec)
   }
+  // We never hit this in windows tests, obviously
+  /* istanbul ignore next */
   return isPosixFile.test(spec)
 }
 
@@ -342,6 +344,12 @@ function fromFile (res, where) {
   res.fetchSpec = path.resolve(where, resolvedPath)
   // re-normalize the slashes in saveSpec due to node:path/win32 behavior in windows
   res.saveSpec = res.saveSpec.split('\\').join('/')
+  // Ignoring because this only happens in windows
+  /* istanbul ignore next */
+  if (res.saveSpec.startsWith('file://')) {
+    // normalization of \\win32\root paths can cause a double / which we don't want
+    res.saveSpec = `file:/${res.saveSpec.slice(7)}`
+  }
   return res
 }