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|
package waiter
import (
mathrand "math/rand"
"strings"
"testing"
"time"
"github.com/aws/smithy-go/rand"
)
func TestComputeDelay(t *testing.T) {
cases := map[string]struct {
totalAttempts int64
minDelay time.Duration
maxDelay time.Duration
maxWaitTime time.Duration
expectedMaxDelays []time.Duration
expectedError string
expectedMinAttempts int
}{
"standard": {
totalAttempts: 8,
minDelay: 2 * time.Second,
maxDelay: 120 * time.Second,
maxWaitTime: 300 * time.Second,
expectedMaxDelays: []time.Duration{2, 4, 8, 16, 32, 64, 120, 120},
expectedMinAttempts: 8,
},
"zero minDelay": {
totalAttempts: 3,
minDelay: 0,
maxDelay: 120 * time.Second,
maxWaitTime: 300 * time.Second,
expectedError: "minDelay must be greater than zero",
},
"zero maxDelay": {
totalAttempts: 3,
minDelay: 10 * time.Second,
maxDelay: 0,
maxWaitTime: 300 * time.Second,
expectedError: "maxDelay must be greater than zero",
},
"zero remaining time": {
totalAttempts: 3,
minDelay: 10 * time.Second,
maxDelay: 20 * time.Second,
maxWaitTime: 0,
expectedMaxDelays: []time.Duration{0},
expectedMinAttempts: 1,
},
"max wait time is less than min delay": {
totalAttempts: 3,
minDelay: 10 * time.Second,
maxDelay: 20 * time.Second,
maxWaitTime: 5 * time.Second,
expectedMaxDelays: []time.Duration{0},
expectedMinAttempts: 1,
},
"large minDelay": {
totalAttempts: 80,
minDelay: 150 * time.Minute,
maxDelay: 200 * time.Minute,
maxWaitTime: 250 * time.Minute,
expectedMinAttempts: 1,
},
"large maxDelay": {
totalAttempts: 80,
minDelay: 15 * time.Minute,
maxDelay: 2000 * time.Minute,
maxWaitTime: 250 * time.Minute,
expectedMinAttempts: 5,
},
}
for name, c := range cases {
t.Run(name, func(t *testing.T) {
// mock smithy-go rand/#Reader
r := rand.Reader
defer func() {
rand.Reader = r
}()
rand.Reader = mathrand.New(mathrand.NewSource(1))
// mock waiter call
delays, err := mockwait(c.totalAttempts, c.minDelay, c.maxDelay, c.maxWaitTime)
if len(c.expectedError) != 0 {
if err == nil {
t.Fatalf("expected error, got none")
}
if e, a := c.expectedError, err.Error(); !strings.Contains(a, e) {
t.Fatalf("expected error %v, got %v instead", e, a)
}
} else if err != nil {
t.Fatalf("expected no error, got %v", err)
}
if e, a := c.expectedMinAttempts, len(delays); e > a {
t.Logf("%v", delays)
t.Fatalf("expected minimum attempts to be %v, got %v", e, a)
}
for i, expectedDelay := range c.expectedMaxDelays {
if e, a := expectedDelay*time.Second, delays[i]; e < a {
t.Fatalf("attempt %d : expected delay to be less than %v, got %v", i+1, e, a)
}
if e, a := c.minDelay, delays[i]; e > a && c.maxWaitTime > c.minDelay {
t.Fatalf("attempt %d : expected delay to be more than %v, got %v", i+1, e, a)
}
}
t.Logf("delays : %v", delays)
})
}
}
func mockwait(maxAttempts int64, minDelay, maxDelay, maxWaitTime time.Duration) ([]time.Duration, error) {
delays := make([]time.Duration, 0)
remainingTime := maxWaitTime
var attempt int64
for {
attempt++
if maxAttempts < attempt {
break
}
delay, err := ComputeDelay(attempt, minDelay, maxDelay, remainingTime)
if err != nil {
return delays, err
}
delays = append(delays, delay)
remainingTime -= delay
if remainingTime < minDelay {
break
}
}
return delays, nil
}
|
