go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/gae/filter/txndefer/filter_test.go (about)

     1  // Copyright 2020 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 txndefer
    16  
    17  import (
    18  	"context"
    19  	"errors"
    20  	"fmt"
    21  	"testing"
    22  
    23  	"go.chromium.org/luci/gae/impl/memory"
    24  	"go.chromium.org/luci/gae/service/datastore"
    25  
    26  	. "github.com/smartystreets/goconvey/convey"
    27  )
    28  
    29  func ExampleFilterRDS() {
    30  	ctx := FilterRDS(memory.Use(context.Background()))
    31  
    32  	datastore.RunInTransaction(ctx, func(ctx context.Context) error {
    33  		Defer(ctx, func(context.Context) { fmt.Println("1") })
    34  		Defer(ctx, func(context.Context) { fmt.Println("2") })
    35  		return nil
    36  	}, nil)
    37  
    38  	// Output:
    39  	// 2
    40  	// 1
    41  }
    42  
    43  func TestFilter(t *testing.T) {
    44  	t.Parallel()
    45  
    46  	Convey("With filter", t, func() {
    47  		ctx := FilterRDS(memory.Use(context.Background()))
    48  
    49  		Convey("Successful txn", func() {
    50  			ctx := context.WithValue(ctx, "123", "random extra value")
    51  			called := false
    52  
    53  			err := datastore.RunInTransaction(ctx, func(ctx context.Context) error {
    54  				Defer(ctx, func(ctx context.Context) {
    55  					So(datastore.CurrentTransaction(ctx), ShouldBeNil)
    56  					So(ctx.Value("123"), ShouldEqual, "random extra value")
    57  					called = true
    58  				})
    59  				return nil
    60  			}, nil)
    61  
    62  			So(err, ShouldBeNil)
    63  			So(called, ShouldBeTrue)
    64  		})
    65  
    66  		Convey("Fatal txn error", func() {
    67  			called := false
    68  
    69  			datastore.RunInTransaction(ctx, func(ctx context.Context) error {
    70  				Defer(ctx, func(context.Context) { called = true })
    71  				return errors.New("boom")
    72  			}, nil)
    73  
    74  			So(called, ShouldBeFalse)
    75  		})
    76  
    77  		Convey("Txn retries", func() {
    78  			attempt := 0
    79  			calls := 0
    80  
    81  			err := datastore.RunInTransaction(ctx, func(ctx context.Context) error {
    82  				attempt++
    83  				Defer(ctx, func(context.Context) { calls++ })
    84  				if attempt < 3 {
    85  					return datastore.ErrConcurrentTransaction
    86  				}
    87  				return nil
    88  			}, nil)
    89  
    90  			So(err, ShouldBeNil)
    91  			So(attempt, ShouldEqual, 3)
    92  			So(calls, ShouldEqual, 1)
    93  		})
    94  	})
    95  }