go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/retry/exponential_test.go (about)

     1  // Copyright 2015 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package retry
    16  
    17  import (
    18  	"context"
    19  	"testing"
    20  	"time"
    21  
    22  	. "github.com/smartystreets/goconvey/convey"
    23  	"go.chromium.org/luci/common/clock/testclock"
    24  )
    25  
    26  func TestExponentialBackoff(t *testing.T) {
    27  	t.Parallel()
    28  
    29  	Convey(`An ExponentialBackoff Iterator, using an instrumented context`, t, func() {
    30  		ctx, _ := testclock.UseTime(context.Background(), time.Date(2015, 1, 1, 0, 0, 0, 0, time.UTC))
    31  		l := ExponentialBackoff{}
    32  
    33  		Convey(`When empty, will Stop immediately.`, func() {
    34  			So(l.Next(ctx, nil), ShouldEqual, Stop)
    35  		})
    36  
    37  		Convey(`Will delay exponentially.`, func() {
    38  			l.Retries = 4
    39  			l.Delay = time.Second
    40  			So(l.Next(ctx, nil), ShouldEqual, 1*time.Second)
    41  			So(l.Next(ctx, nil), ShouldEqual, 2*time.Second)
    42  			So(l.Next(ctx, nil), ShouldEqual, 4*time.Second)
    43  			So(l.Next(ctx, nil), ShouldEqual, 8*time.Second)
    44  			So(l.Next(ctx, nil), ShouldEqual, Stop)
    45  		})
    46  
    47  		Convey(`Will bound exponential delay when MaxDelay is set.`, func() {
    48  			l.Retries = 4
    49  			l.Delay = time.Second
    50  			l.MaxDelay = 4 * time.Second
    51  			So(l.Next(ctx, nil), ShouldEqual, 1*time.Second)
    52  			So(l.Next(ctx, nil), ShouldEqual, 2*time.Second)
    53  			So(l.Next(ctx, nil), ShouldEqual, 4*time.Second)
    54  			So(l.Next(ctx, nil), ShouldEqual, 4*time.Second)
    55  			So(l.Next(ctx, nil), ShouldEqual, Stop)
    56  		})
    57  	})
    58  }