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|
package strategy
import (
"testing"
"time"
)
// timeMarginOfError represents the acceptable amount of time that may pass for
// a time-based (sleep) unit before considering invalid.
const timeMarginOfError = time.Millisecond
func TestLimit(t *testing.T) {
// Strategy attempts are 0-based.
// Treat this functionally as n+1.
const attemptLimit = 3
strategy := Limit(attemptLimit)
if !strategy(0) {
t.Error("strategy expected to return true")
}
if !strategy(1) {
t.Error("strategy expected to return true")
}
if !strategy(2) {
t.Error("strategy expected to return true")
}
if strategy(3) {
t.Error("strategy expected to return false")
}
}
func TestDelay(t *testing.T) {
const delayDuration = 10 * timeMarginOfError
strategy := Delay(delayDuration)
if now := time.Now(); !strategy(0) || delayDuration > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
delayDuration,
)
}
if now := time.Now(); !strategy(5) || (delayDuration/10) < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
}
func TestWait(t *testing.T) {
strategy := Wait()
if now := time.Now(); !strategy(0) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
if now := time.Now(); !strategy(999) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
}
func TestWaitWithDuration(t *testing.T) {
const waitDuration = 10 * timeMarginOfError
strategy := Wait(waitDuration)
if now := time.Now(); !strategy(0) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
if now := time.Now(); !strategy(1) || waitDuration > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
waitDuration,
)
}
}
func TestWaitWithMultipleDurations(t *testing.T) {
waitDurations := []time.Duration{
10 * timeMarginOfError,
20 * timeMarginOfError,
30 * timeMarginOfError,
40 * timeMarginOfError,
}
strategy := Wait(waitDurations...)
if now := time.Now(); !strategy(0) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
if now := time.Now(); !strategy(1) || waitDurations[0] > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
waitDurations[0],
)
}
if now := time.Now(); !strategy(3) || waitDurations[2] > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
waitDurations[2],
)
}
if now := time.Now(); !strategy(999) || waitDurations[len(waitDurations)-1] > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
waitDurations[len(waitDurations)-1],
)
}
}
func TestBackoff(t *testing.T) {
const testCycles = 10
const backoffDuration = testCycles * timeMarginOfError
const algorithmDurationBase = timeMarginOfError
algorithm := func(attempt uint) time.Duration {
return backoffDuration - (time.Duration(attempt) * algorithmDurationBase)
}
strategy := Backoff(algorithm)
if now := time.Now(); !strategy(0) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
for i := uint(1); i < testCycles; i++ {
expectedResult := algorithm(i)
if expectedResult < 0 {
t.Errorf(
"algorithm returned a negative duration %s",
expectedResult,
)
}
if now := time.Now(); !strategy(i) || expectedResult > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
expectedResult,
)
}
}
}
func TestBackoffWithJitter(t *testing.T) {
const testCycles = 10
const backoffDuration = 2 * testCycles * timeMarginOfError
const algorithmDurationBase = timeMarginOfError
algorithm := func(attempt uint) time.Duration {
return backoffDuration - (time.Duration(attempt) * algorithmDurationBase)
}
transformation := func(duration time.Duration) time.Duration {
return duration - (backoffDuration / 2)
}
strategy := BackoffWithJitter(algorithm, transformation)
if now := time.Now(); !strategy(0) || timeMarginOfError < time.Since(now) {
t.Error("strategy expected to return true in ~0 time")
}
for i := uint(1); i < testCycles; i++ {
expectedResult := transformation(algorithm(i))
if expectedResult < 0 {
t.Errorf(
"transformation returned a negative duration %s",
expectedResult,
)
}
if now := time.Now(); !strategy(i) || expectedResult > time.Since(now) {
t.Errorf(
"strategy expected to return true in %s",
expectedResult,
)
}
}
}
func TestNoJitter(t *testing.T) {
transformation := noJitter()
for i := uint(0); i < 10; i++ {
duration := time.Duration(i) * timeMarginOfError
result := transformation(duration)
expected := duration
if result != expected {
t.Errorf("transformation expected to return a %s duration, but received %s instead", expected, result)
}
}
}
|
