syncthing/vendor/github.com/onsi/gomega/matchers/receive_matcher.go
2017-12-29 11:38:00 +00:00

123 lines
3.2 KiB
Go

package matchers
import (
"fmt"
"reflect"
"github.com/onsi/gomega/format"
)
type ReceiveMatcher struct {
Arg interface{}
receivedValue reflect.Value
channelClosed bool
}
func (matcher *ReceiveMatcher) Match(actual interface{}) (success bool, err error) {
if !isChan(actual) {
return false, fmt.Errorf("ReceiveMatcher expects a channel. Got:\n%s", format.Object(actual, 1))
}
channelType := reflect.TypeOf(actual)
channelValue := reflect.ValueOf(actual)
if channelType.ChanDir() == reflect.SendDir {
return false, fmt.Errorf("ReceiveMatcher matcher cannot be passed a send-only channel. Got:\n%s", format.Object(actual, 1))
}
var subMatcher omegaMatcher
var hasSubMatcher bool
if matcher.Arg != nil {
subMatcher, hasSubMatcher = (matcher.Arg).(omegaMatcher)
if !hasSubMatcher {
argType := reflect.TypeOf(matcher.Arg)
if argType.Kind() != reflect.Ptr {
return false, fmt.Errorf("Cannot assign a value from the channel:\n%s\nTo:\n%s\nYou need to pass a pointer!", format.Object(actual, 1), format.Object(matcher.Arg, 1))
}
assignable := channelType.Elem().AssignableTo(argType.Elem())
if !assignable {
return false, fmt.Errorf("Cannot assign a value from the channel:\n%s\nTo:\n%s", format.Object(actual, 1), format.Object(matcher.Arg, 1))
}
}
}
winnerIndex, value, open := reflect.Select([]reflect.SelectCase{
reflect.SelectCase{Dir: reflect.SelectRecv, Chan: channelValue},
reflect.SelectCase{Dir: reflect.SelectDefault},
})
var closed bool
var didReceive bool
if winnerIndex == 0 {
closed = !open
didReceive = open
}
matcher.channelClosed = closed
if closed {
return false, nil
}
if hasSubMatcher {
if didReceive {
matcher.receivedValue = value
return subMatcher.Match(matcher.receivedValue.Interface())
}
return false, nil
}
if didReceive {
if matcher.Arg != nil {
outValue := reflect.ValueOf(matcher.Arg)
reflect.Indirect(outValue).Set(value)
}
return true, nil
}
return false, nil
}
func (matcher *ReceiveMatcher) FailureMessage(actual interface{}) (message string) {
subMatcher, hasSubMatcher := (matcher.Arg).(omegaMatcher)
closedAddendum := ""
if matcher.channelClosed {
closedAddendum = " The channel is closed."
}
if hasSubMatcher {
if matcher.receivedValue.IsValid() {
return subMatcher.FailureMessage(matcher.receivedValue.Interface())
}
return "When passed a matcher, ReceiveMatcher's channel *must* receive something."
}
return format.Message(actual, "to receive something."+closedAddendum)
}
func (matcher *ReceiveMatcher) NegatedFailureMessage(actual interface{}) (message string) {
subMatcher, hasSubMatcher := (matcher.Arg).(omegaMatcher)
closedAddendum := ""
if matcher.channelClosed {
closedAddendum = " The channel is closed."
}
if hasSubMatcher {
if matcher.receivedValue.IsValid() {
return subMatcher.NegatedFailureMessage(matcher.receivedValue.Interface())
}
return "When passed a matcher, ReceiveMatcher's channel *must* receive something."
}
return format.Message(actual, "not to receive anything."+closedAddendum)
}
func (matcher *ReceiveMatcher) MatchMayChangeInTheFuture(actual interface{}) bool {
if !isChan(actual) {
return false
}
return !matcher.channelClosed
}