// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package fs_test

import (
	"errors"
	. "io/fs"
	"testing"
)

type subOnly struct{ SubFS }

func (subOnly) Open(name string) (File, error) { return nil, ErrNotExist }

func TestSub(t *testing.T) {
	check := func(desc string, sub FS, err error) {
		t.Helper()
		if err != nil {

// use the same language tag for the selection of any locale-specific services.
// For example, it is utterly confusing to substitute spelled-out numbers
// or dates in one language in text of another language.
// More subtly confusing is using the wrong sorting order or casing
// algorithm for a certain language.
//
// All the packages in x/text that provide locale-specific services
// (e.g. collate, cases) should be initialized with the tag that was

                            below), the selector expression syntax itself supports
                            negation.  The two types of negation are subtly different.
                            One negates the set of matched endpoints, the other negates
                            the whole match: \n \tSelector = \"!has(my_label)\" matches

                            below), the selector expression syntax itself supports
                            negation.  The two types of negation are subtly different.
                            One negates the set of matched endpoints, the other negates
                            the whole match: \n \tSelector = \"!has(my_label)\" matches

	PersistOldestWinsHeuristicForVirtualServiceHostMatching = env.Register("PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING", false,
		"If enabled, istiod will persist the oldest first heuristic for subtly conflicting traffic policy selection"+
			"(such as with overlapping wildcard hosts)").Get()

	Enable100ContinueHeaders = env.Register("ENABLE_100_CONTINUE_HEADERS", true,

                            below), the selector expression syntax itself supports
                            negation.  The two types of negation are subtly different.
                            One negates the set of matched endpoints, the other negates
                            the whole match: \n \tSelector = \"!has(my_label)\" matches