github.com/linapex/ethereum-go-chinese@v0.0.0-20190316121929-f8b7a73c3fa1/event/subscription_test.go (about)

     1  
     2  //<developer>
     3  //    <name>linapex 曹一峰</name>
     4  //    <email>linapex@163.com</email>
     5  //    <wx>superexc</wx>
     6  //    <qqgroup>128148617</qqgroup>
     7  //    <url>https://jsq.ink</url>
     8  //    <role>pku engineer</role>
     9  //    <date>2019-03-16 19:16:38</date>
    10  //</624450091217850368>
    11  
    12  
    13  package event
    14  
    15  import (
    16  	"context"
    17  	"errors"
    18  	"testing"
    19  	"time"
    20  )
    21  
    22  var errInts = errors.New("error in subscribeInts")
    23  
    24  func subscribeInts(max, fail int, c chan<- int) Subscription {
    25  	return NewSubscription(func(quit <-chan struct{}) error {
    26  		for i := 0; i < max; i++ {
    27  			if i >= fail {
    28  				return errInts
    29  			}
    30  			select {
    31  			case c <- i:
    32  			case <-quit:
    33  				return nil
    34  			}
    35  		}
    36  		return nil
    37  	})
    38  }
    39  
    40  func TestNewSubscriptionError(t *testing.T) {
    41  	t.Parallel()
    42  
    43  	channel := make(chan int)
    44  	sub := subscribeInts(10, 2, channel)
    45  loop:
    46  	for want := 0; want < 10; want++ {
    47  		select {
    48  		case got := <-channel:
    49  			if got != want {
    50  				t.Fatalf("wrong int %d, want %d", got, want)
    51  			}
    52  		case err := <-sub.Err():
    53  			if err != errInts {
    54  				t.Fatalf("wrong error: got %q, want %q", err, errInts)
    55  			}
    56  			if want != 2 {
    57  				t.Fatalf("got errInts at int %d, should be received at 2", want)
    58  			}
    59  			break loop
    60  		}
    61  	}
    62  	sub.Unsubscribe()
    63  
    64  	err, ok := <-sub.Err()
    65  	if err != nil {
    66  		t.Fatal("got non-nil error after Unsubscribe")
    67  	}
    68  	if ok {
    69  		t.Fatal("channel still open after Unsubscribe")
    70  	}
    71  }
    72  
    73  func TestResubscribe(t *testing.T) {
    74  	t.Parallel()
    75  
    76  	var i int
    77  	nfails := 6
    78  	sub := Resubscribe(100*time.Millisecond, func(ctx context.Context) (Subscription, error) {
    79  //fmt.printf（“调用%d@%v\n”，i，time.now（））
    80  		i++
    81  		if i == 2 {
    82  //将第二次失败延迟一点以重置重新预订间隔。
    83  			time.Sleep(200 * time.Millisecond)
    84  		}
    85  		if i < nfails {
    86  			return nil, errors.New("oops")
    87  		}
    88  		sub := NewSubscription(func(unsubscribed <-chan struct{}) error { return nil })
    89  		return sub, nil
    90  	})
    91  
    92  	<-sub.Err()
    93  	if i != nfails {
    94  		t.Fatalf("resubscribe function called %d times, want %d times", i, nfails)
    95  	}
    96  }
    97  
    98  func TestResubscribeAbort(t *testing.T) {
    99  	t.Parallel()
   100  
   101  	done := make(chan error)
   102  	sub := Resubscribe(0, func(ctx context.Context) (Subscription, error) {
   103  		select {
   104  		case <-ctx.Done():
   105  			done <- nil
   106  		case <-time.After(2 * time.Second):
   107  			done <- errors.New("context given to resubscribe function not canceled within 2s")
   108  		}
   109  		return nil, nil
   110  	})
   111  
   112  	sub.Unsubscribe()
   113  	if err := <-done; err != nil {
   114  		t.Fatal(err)
   115  	}
   116  }
   117