if _, dup := decompressors.LoadOrStore(method, dcomp); dup {
		panic("decompressor already registered")
	}
}

// RegisterCompressor registers custom compressors for a specified method ID.
// The common methods [Store] and [Deflate] are built in.
func RegisterCompressor(method uint16, comp Compressor) {
	if _, dup := compressors.LoadOrStore(method, comp); dup {
		panic("compressor already registered")
	}
}

	}
}

type panicReader struct{ panic bool }

func (r panicReader) Read(p []byte) (int, error) {
	if r.panic {
		panic("oops")
	}
	return 0, io.EOF
}

// Make sure that an empty Buffer remains empty when
// it is "grown" before a Read that panics
func TestReadFromPanicReader(t *testing.T) {

	// First verify non-panic behaviour
	var buf Buffer

			if err := tx.First(&User{}, "name = ?", user.Name).Error; err != nil {
				t.Fatalf("Should find saved record")
			}

			panic("force panic")
		})
	})

	if err := DB.First(&User{}, "name = ?", "transaction-block-3").Error; err == nil {
		t.Fatalf("Should not find record after panic rollback")
	}
}

func TestTransactionRaiseErrorOnRollbackAfterCommit(t *testing.T) {
	tx := DB.Begin()

The [GODEBUG History](#history) gives the exact defaults for each Go toolchain version.
For example, Go 1.21 introduces the `panicnil` setting,
controlling whether `panic(nil)` is allowed;
it defaults to `panicnil=0`, making `panic(nil)` a run-time error.
Using `panicnil=1` restores the behavior of Go 1.20 and earlier.

When compiling a work module or workspace that declares

func TestNegativeRead(t *testing.T) {
	// should panic with a description pointing at the reader, not at itself.
	// (should NOT panic with slice index error, for example.)
	b := NewReader(new(negativeReader))
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("read did not panic")
		case error:

//
// f(NewDummyDataGen(100, 0)) == f(NewDummyDataGen(50, 0)) + f(NewDummyDataGen(50, 50))
func NewDummyDataGen(totalLength, skipOffset int64) io.ReadSeeker {
	if totalLength < 0 {
		panic("Negative length passed to DummyDataGen!")
	}
	if skipOffset < 0 {
		panic("Negative rotations are not allowed")
	}

	skipOffset %= int64(len(alphabets))
	const multiply = 100
	as := bytes.Repeat(alphabets, multiply)

	success := lm.unlock(isWriteLock)
	if !success {
		panic("Trying to Unlock() while no Lock() is active")
	}
}

// RUnlock releases a read lock held on lm.
//
// It is a run-time error if lm is not locked on entry to RUnlock.
func (lm *LRWMutex) RUnlock() {
	isWriteLock := false
	success := lm.unlock(isWriteLock)
	if !success {
		panic("Trying to RUnlock() while no RLock() is active")
	}
}

}

func (w *Walker) emitf(format string, args ...any) {
	f := strings.Join(w.scope, ", ") + ", " + fmt.Sprintf(format, args...)
	if strings.Contains(f, "\n") {
		panic("feature contains newlines: " + f)
	}

	if _, dup := w.features[f]; dup {
		panic("duplicate feature inserted: " + f)
	}
	w.features[f] = true

	if verbose {
		log.Printf("feature: %s", f)
	}
}

func (s *Singleton[T]) IsSet() bool {
	select {
	case <-s.set:
		return true
	default:
		return false
	}
}

// Set the value and unblock all Get requests.
// This may only be called once, a second call will panic.
func (s *Singleton[T]) Set(v *T) {
	s.v = v
	close(s.set)

	br := bufio.NewReader(bytes.NewReader(b))
loop:
	for {
		_, err := br.ReadByte()
		switch err {
		case nil:
			continue loop
		case io.EOF:
			break loop
		default:
			panic(err)
		}
	}
}

func BenchmarkScanner(b *testing.B) {
	b.Run("small", func(b *testing.B) {
		for b.Loop() {
			benchmarkScanner(smallInput)
		}
	})
	b.Run("medium", func(b *testing.B) {