syncthing/vendor/github.com/onsi/gomega/internal/asyncassertion/async_assertion.go

190 lines
4.9 KiB
Go
Raw Normal View History

package asyncassertion
import (
"errors"
"fmt"
"reflect"
"time"
"github.com/onsi/gomega/internal/oraclematcher"
"github.com/onsi/gomega/types"
)
type AsyncAssertionType uint
const (
AsyncAssertionTypeEventually AsyncAssertionType = iota
AsyncAssertionTypeConsistently
)
type AsyncAssertion struct {
asyncType AsyncAssertionType
actualInput interface{}
timeoutInterval time.Duration
pollingInterval time.Duration
fail types.GomegaFailHandler
offset int
}
func New(asyncType AsyncAssertionType, actualInput interface{}, fail types.GomegaFailHandler, timeoutInterval time.Duration, pollingInterval time.Duration, offset int) *AsyncAssertion {
actualType := reflect.TypeOf(actualInput)
if actualType.Kind() == reflect.Func {
if actualType.NumIn() != 0 || actualType.NumOut() == 0 {
panic("Expected a function with no arguments and one or more return values.")
}
}
return &AsyncAssertion{
asyncType: asyncType,
actualInput: actualInput,
fail: fail,
timeoutInterval: timeoutInterval,
pollingInterval: pollingInterval,
offset: offset,
}
}
func (assertion *AsyncAssertion) Should(matcher types.GomegaMatcher, optionalDescription ...interface{}) bool {
return assertion.match(matcher, true, optionalDescription...)
}
func (assertion *AsyncAssertion) ShouldNot(matcher types.GomegaMatcher, optionalDescription ...interface{}) bool {
return assertion.match(matcher, false, optionalDescription...)
}
func (assertion *AsyncAssertion) buildDescription(optionalDescription ...interface{}) string {
switch len(optionalDescription) {
case 0:
return ""
default:
return fmt.Sprintf(optionalDescription[0].(string), optionalDescription[1:]...) + "\n"
}
}
func (assertion *AsyncAssertion) actualInputIsAFunction() bool {
actualType := reflect.TypeOf(assertion.actualInput)
return actualType.Kind() == reflect.Func && actualType.NumIn() == 0 && actualType.NumOut() > 0
}
func (assertion *AsyncAssertion) pollActual() (interface{}, error) {
if assertion.actualInputIsAFunction() {
values := reflect.ValueOf(assertion.actualInput).Call([]reflect.Value{})
extras := []interface{}{}
for _, value := range values[1:] {
extras = append(extras, value.Interface())
}
success, message := vetExtras(extras)
if !success {
return nil, errors.New(message)
}
return values[0].Interface(), nil
}
return assertion.actualInput, nil
}
func (assertion *AsyncAssertion) matcherMayChange(matcher types.GomegaMatcher, value interface{}) bool {
if assertion.actualInputIsAFunction() {
return true
}
return oraclematcher.MatchMayChangeInTheFuture(matcher, value)
}
func (assertion *AsyncAssertion) match(matcher types.GomegaMatcher, desiredMatch bool, optionalDescription ...interface{}) bool {
timer := time.Now()
timeout := time.After(assertion.timeoutInterval)
description := assertion.buildDescription(optionalDescription...)
var matches bool
var err error
mayChange := true
value, err := assertion.pollActual()
if err == nil {
mayChange = assertion.matcherMayChange(matcher, value)
matches, err = matcher.Match(value)
}
fail := func(preamble string) {
errMsg := ""
message := ""
if err != nil {
errMsg = "Error: " + err.Error()
} else {
if desiredMatch {
message = matcher.FailureMessage(value)
} else {
message = matcher.NegatedFailureMessage(value)
}
}
assertion.fail(fmt.Sprintf("%s after %.3fs.\n%s%s%s", preamble, time.Since(timer).Seconds(), description, message, errMsg), 3+assertion.offset)
}
if assertion.asyncType == AsyncAssertionTypeEventually {
for {
if err == nil && matches == desiredMatch {
return true
}
if !mayChange {
fail("No future change is possible. Bailing out early")
return false
}
select {
case <-time.After(assertion.pollingInterval):
value, err = assertion.pollActual()
if err == nil {
mayChange = assertion.matcherMayChange(matcher, value)
matches, err = matcher.Match(value)
}
case <-timeout:
fail("Timed out")
return false
}
}
} else if assertion.asyncType == AsyncAssertionTypeConsistently {
for {
if !(err == nil && matches == desiredMatch) {
fail("Failed")
return false
}
if !mayChange {
return true
}
select {
case <-time.After(assertion.pollingInterval):
value, err = assertion.pollActual()
if err == nil {
mayChange = assertion.matcherMayChange(matcher, value)
matches, err = matcher.Match(value)
}
case <-timeout:
return true
}
}
}
return false
}
func vetExtras(extras []interface{}) (bool, string) {
for i, extra := range extras {
if extra != nil {
zeroValue := reflect.Zero(reflect.TypeOf(extra)).Interface()
if !reflect.DeepEqual(zeroValue, extra) {
message := fmt.Sprintf("Unexpected non-nil/non-zero extra argument at index %d:\n\t<%T>: %#v", i+1, extra, extra)
return false, message
}
}
}
return true, ""
}