return "json: invalid UTF-8 in string: " + strconv.Quote(e.S)
}

// A MarshalerError represents an error from calling a
// [Marshaler.MarshalJSON] or [encoding.TextMarshaler.MarshalText] method.
type MarshalerError struct {
	Type       reflect.Type
	Err        error
	sourceFunc string
}

func (e *MarshalerError) Error() string {
	srcFunc := e.sourceFunc
	if srcFunc == "" {
		srcFunc = "MarshalJSON"

	const errText = "json: test error"

	tests := []struct {
		CaseName
		err  *MarshalerError
		want string
	}{{
		Name(""),
		&MarshalerError{st, fmt.Errorf(errText), ""},
		"json: error calling MarshalJSON for type " + st.String() + ": " + errText,
	}, {
		Name(""),
		&MarshalerError{st, fmt.Errorf(errText), "TestMarshalerError"},

		{"InvalidUnmarshalError", Type, 0},
		{"InvalidUnmarshalError.Type", Field, 0},
		{"Marshal", Func, 0},
		{"MarshalIndent", Func, 0},
		{"Marshaler", Type, 0},
		{"MarshalerError", Type, 0},
		{"MarshalerError.Err", Field, 0},
		{"MarshalerError.Type", Field, 0},
		{"NewDecoder", Func, 0},
		{"NewEncoder", Func, 0},
		{"Number", Type, 1},
		{"RawMessage", Type, 0},
		{"SyntaxError", Type, 0},

pkg debug/elf, type Symbol struct, Library string
pkg debug/elf, type Symbol struct, Version string
pkg encoding/csv, method (*ParseError) Unwrap() error
pkg encoding/json, method (*MarshalerError) Unwrap() error
pkg errors, func As(error, interface{}) bool
pkg errors, func Is(error, error) bool
pkg errors, func Unwrap(error) error
pkg go/constant, func Make(interface{}) Value

pkg encoding/json, type Marshaler interface { MarshalJSON }
pkg encoding/json, type Marshaler interface, MarshalJSON() ([]uint8, error)
pkg encoding/json, type MarshalerError struct
pkg encoding/json, type MarshalerError struct, Err error
pkg encoding/json, type MarshalerError struct, Type reflect.Type
pkg encoding/json, type RawMessage []uint8
pkg encoding/json, type SyntaxError struct