local: Fix creating data dirs

internal/fs/path_prefix_test.go

@@ -0,0 +1,52 @@
+package fs
+
+import (
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func fromSlashAbs(p string) string {
+	if runtime.GOOS == "windows" {
+		if len(p) > 0 && p[0] == '/' {
+			p = "c:" + p
+		}
+	}
+
+	return filepath.FromSlash(p)
+}
+
+func TestHasPathPrefix(t *testing.T) {
+	var tests = []struct {
+		base, p string
+		result  bool
+	}{
+		{"", "", false},
+		{"/", "", false},
+		{"/", "x", false},
+		{"x", "/", false},
+		{"/", "/x", true},
+		{"/x", "/y", false},
+		{"/home/user/foo", "/home", false},
+		{"/home/user/foo/", "/home", false},
+		{"/home/user/foo", "/home/", false},
+		{"/home/user/foo/", "/home/", false},
+		{"/home/user/foo", "/home/user/foo/bar", true},
+		{"/home/user/foo", "/home/user/foo/bar/baz/x/y/z", true},
+		{"/home/user/foo", "/home/user/foobar", false},
+		{"/home/user/Foo", "/home/user/foo/bar/baz", false},
+		{"/home/user/foo", "/home/user/Foo/bar/baz", false},
+	}
+
+	for _, test := range tests {
+		t.Run("", func(t *testing.T) {
+			base := fromSlashAbs(test.base)
+			p := fromSlashAbs(test.p)
+			result := HasPathPrefix(base, p)
+			if result != test.result {
+				t.Fatalf("wrong result for HasPathPrefix(%q, %q): want %v, got %v",
+					base, p, test.result, result)
+			}
+		})
+	}
+}