package matchers import ( "fmt" "reflect" "github.com/onsi/gomega/format" ) type BeSentMatcher struct { Arg interface{} channelClosed bool } func (matcher *BeSentMatcher) Match(actual interface{}) (success bool, err error) { if !isChan(actual) { return false, fmt.Errorf("BeSent expects a channel. Got:\n%s", format.Object(actual, 1)) } channelType := reflect.TypeOf(actual) channelValue := reflect.ValueOf(actual) if channelType.ChanDir() == reflect.RecvDir { return false, fmt.Errorf("BeSent matcher cannot be passed a receive-only channel. Got:\n%s", format.Object(actual, 1)) } argType := reflect.TypeOf(matcher.Arg) assignable := argType.AssignableTo(channelType.Elem()) if !assignable { return false, fmt.Errorf("Cannot pass:\n%s to the channel:\n%s\nThe types don't match.", format.Object(matcher.Arg, 1), format.Object(actual, 1)) } argValue := reflect.ValueOf(matcher.Arg) defer func() { if e := recover(); e != nil { success = false err = fmt.Errorf("Cannot send to a closed channel") matcher.channelClosed = true } }() winnerIndex, _, _ := reflect.Select([]reflect.SelectCase{ {Dir: reflect.SelectSend, Chan: channelValue, Send: argValue}, {Dir: reflect.SelectDefault}, }) var didSend bool if winnerIndex == 0 { didSend = true } return didSend, nil } func (matcher *BeSentMatcher) FailureMessage(actual interface{}) (message string) { return format.Message(actual, "to send:", matcher.Arg) } func (matcher *BeSentMatcher) NegatedFailureMessage(actual interface{}) (message string) { return format.Message(actual, "not to send:", matcher.Arg) } func (matcher *BeSentMatcher) MatchMayChangeInTheFuture(actual interface{}) bool { if !isChan(actual) { return false } return !matcher.channelClosed }