"runtime/metrics"
	"testing"
)

func TestPanicNil(t *testing.T) {
	t.Run("default", func(t *testing.T) {
		checkPanicNil(t, new(runtime.PanicNilError))
	})
	t.Run("GODEBUG=panicnil=0", func(t *testing.T) {
		t.Setenv("GODEBUG", "panicnil=0")
		checkPanicNil(t, new(runtime.PanicNilError))
	})
	t.Run("GODEBUG=panicnil=1", func(t *testing.T) {
		t.Setenv("GODEBUG", "panicnil=1")
		checkPanicNil(t, nil)
	})
}

			panic("Bad varint")
		}
	}
}

// A PanicNilError happens when code calls panic(nil).
//
// Before Go 1.21, programs that called panic(nil) observed recover returning nil.
// Starting in Go 1.21, programs that call panic(nil) observe recover returning a *PanicNilError.
// Programs can change back to the old behavior by setting GODEBUG=panicnil=1.
type PanicNilError struct {

pkg regexp, method (*Regexp) UnmarshalText([]uint8) error #46159
pkg runtime, method (*PanicNilError) Error() string #25448
pkg runtime, method (*PanicNilError) RuntimeError() #25448
pkg runtime, method (*Pinner) Pin(interface{}) #46787
pkg runtime, method (*Pinner) Unpin() #46787
pkg runtime, type PanicNilError struct #25448
pkg runtime, type Pinner struct #46787

	calls := 0
	f := sync.OnceFunc(func() {
		calls++
		panic(nil)
	})
	testOncePanicWith(t, &calls, f, func(label string, p any) {
		switch p.(type) {
		case nil, *runtime.PanicNilError:
			return
		}
		t.Fatalf("%s: want nil panic, got %v", label, p)
	})
}

func TestOnceFuncGoexit(t *testing.T) {
	// If f calls Goexit, the results are unspecified. But check that f doesn't

		{"(*Func).Name", Method, 0},
		{"(*MemProfileRecord).InUseBytes", Method, 0},
		{"(*MemProfileRecord).InUseObjects", Method, 0},
		{"(*MemProfileRecord).Stack", Method, 0},
		{"(*PanicNilError).Error", Method, 21},
		{"(*PanicNilError).RuntimeError", Method, 21},
		{"(*Pinner).Pin", Method, 21},
		{"(*Pinner).Unpin", Method, 21},
		{"(*StackRecord).Stack", Method, 0},
		{"(*TypeAssertionError).Error", Method, 0},