fastwalk: fix tests for Windows/MSYS

This commit fixes the tests so that they work when ran under MSYS on
Windows (and Git Bash). The issue is that on MSYS we default to using
forward slashes so direct path comparisons failed - the fix is to
normalize the paths before comparison.

Author: charlievieth

fastwalk_test.go

@@ -135,6 +135,9 @@ func testFastWalkConf(t *testing.T, conf *fastwalk.Config, files map[string]stri
 		}
 		mu.Lock()
 		defer mu.Unlock()
+		// Normalize paths for Windows
+		path = filepath.FromSlash(path)
+		tempdir = filepath.FromSlash(tempdir)
 		if !strings.HasPrefix(path, tempdir) {
 			t.Errorf("bogus prefix on %q, expect %q", path, tempdir)
 		}
@@ -457,6 +460,9 @@ func TestFastWalk_WindowsRootPaths(t *testing.T) {
 	//
 	// https://github.com/charlievieth/fastwalk/issues/37
 	t.Run("FullyQualified", func(t *testing.T) {
+		if _, ok := os.LookupEnv("MSYSTEM"); ok {
+			t.Skip("test not supported when running under MSYS (or Git Bash)")
+		}
 		root := vol + `\`
 		if sameFile(t, pwd, root) {
 			t.Skipf("the current working directory (%s) is the disk root: %s", pwd, root)
@@ -561,7 +567,7 @@ func TestFastWalk_WindowsRootPaths(t *testing.T) {
 			if path == vol {
 				continue // Clean("C:") => "C:."
 			}
-			if s := filepath.Clean(path); s != path {
+			if s := filepath.Clean(path); s != filepath.FromSlash(path) {
 				t.Errorf(`filepath.Clean("%s") == "%s"`, path, s)
 			}
 		}