package errors_test import ( "errors" "fmt" "testing" "github.com/stretchr/testify/assert" liberrors "github.com/rclone/rclone/lib/errors" ) func TestWalk(t *testing.T) { origin := errors.New("origin") for _, test := range []struct { err error calls int last error }{ {causerError{nil}, 1, causerError{nil}}, {wrapperError{nil}, 1, wrapperError{nil}}, {reflectError{nil}, 1, reflectError{nil}}, {causerError{origin}, 2, origin}, {wrapperError{origin}, 2, origin}, {reflectError{origin}, 2, origin}, {causerError{reflectError{origin}}, 3, origin}, {wrapperError{causerError{origin}}, 3, origin}, {reflectError{wrapperError{origin}}, 3, origin}, {causerError{reflectError{causerError{origin}}}, 4, origin}, {wrapperError{causerError{wrapperError{origin}}}, 4, origin}, {reflectError{wrapperError{reflectError{origin}}}, 4, origin}, {stopError{nil}, 1, stopError{nil}}, {stopError{causerError{nil}}, 1, stopError{causerError{nil}}}, {stopError{wrapperError{nil}}, 1, stopError{wrapperError{nil}}}, {stopError{reflectError{nil}}, 1, stopError{reflectError{nil}}}, {causerError{stopError{origin}}, 2, stopError{origin}}, {wrapperError{stopError{origin}}, 2, stopError{origin}}, {reflectError{stopError{origin}}, 2, stopError{origin}}, {causerError{reflectError{stopError{nil}}}, 3, stopError{nil}}, {wrapperError{causerError{stopError{nil}}}, 3, stopError{nil}}, {reflectError{wrapperError{stopError{nil}}}, 3, stopError{nil}}, } { var last error calls := 0 liberrors.Walk(test.err, func(err error) bool { calls++ last = err _, stop := err.(stopError) return stop }) assert.Equal(t, test.calls, calls) assert.Equal(t, test.last, last) } } type causerError struct { err error } type wrapperError struct { err error } type reflectError struct { Err error } type stopError struct { err error } func (e causerError) Error() string { return fmt.Sprintf("causerError(%s)", e.err) } func (e causerError) Cause() error { return e.err } func (e wrapperError) Unwrap() error { return e.err } func (e wrapperError) Error() string { return fmt.Sprintf("wrapperError(%s)", e.err) } func (e reflectError) Error() string { return fmt.Sprintf("reflectError(%s)", e.Err) } func (e stopError) Error() string { return fmt.Sprintf("stopError(%s)", e.err) } func (e stopError) Cause() error { return e.err }