package conditions

import (
	"errors"
	"fmt"
	"testing"
)

// **A test may take the store away while the keeper is still telling.** The keeper keeps every
// transition from a goroutine of its own, so the memory store's failure is read there while a test
// switches it: it is switched under the store's lock, or the race detector fails the suite at random
// (it once failed TestAnUnreadableStoreClearsNothing). A hundred transitions still being kept while
// the failure is switched a hundred times makes the race certain, not rare, when the lock is skipped.
func TestTheStoreIsTakenAwayWhileTheKeeperIsTelling(t *testing.T) {
	k, store, told, _ := keeper(t)
	ctx := t.Context()
	const n = 100
	for i := range n {
		if _, err := k.Observe(ctx, silent(fmt.Sprintf("m%d", i))); err != nil {
			t.Fatal(err)
		}
	}
	for range n {
		store.SetFail(errors.New("the bus is away"))
		store.SetFail(nil)
	}
	told.SetFail(errors.New("no responders"))
	told.SetFail(nil)
	settled(t, told, n)
}