github.com/prysmaticlabs/prysm@v1.4.4/shared/event/subscription_test.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package event
    18  
    19  import (
    20  	"context"
    21  	"errors"
    22  	"testing"
    23  	"time"
    24  
    25  	"github.com/prysmaticlabs/prysm/shared/testutil/require"
    26  )
    27  
    28  var errInts = errors.New("error in subscribeInts")
    29  
    30  func subscribeInts(max, fail int, c chan<- int) Subscription {
    31  	return NewSubscription(func(quit <-chan struct{}) error {
    32  		for i := 0; i < max; i++ {
    33  			if i >= fail {
    34  				return errInts
    35  			}
    36  			select {
    37  			case c <- i:
    38  			case <-quit:
    39  				return nil
    40  			}
    41  		}
    42  		return nil
    43  	})
    44  }
    45  
    46  func TestNewSubscriptionError(t *testing.T) {
    47  	t.Parallel()
    48  
    49  	channel := make(chan int)
    50  	sub := subscribeInts(10, 2, channel)
    51  loop:
    52  	for want := 0; want < 10; want++ {
    53  		select {
    54  		case got := <-channel:
    55  			require.Equal(t, want, got)
    56  		case err := <-sub.Err():
    57  			require.Equal(t, errInts, err)
    58  			require.Equal(t, 2, want)
    59  			break loop
    60  		}
    61  	}
    62  	sub.Unsubscribe()
    63  
    64  	err, ok := <-sub.Err()
    65  	require.NoError(t, err)
    66  	if ok {
    67  		t.Fatal("channel still open after Unsubscribe")
    68  	}
    69  }
    70  
    71  func TestResubscribe(t *testing.T) {
    72  	t.Parallel()
    73  
    74  	var i int
    75  	nfails := 6
    76  	sub := Resubscribe(100*time.Millisecond, func(ctx context.Context) (Subscription, error) {
    77  		// fmt.Printf("call #%d @ %v\n", i, time.Now())
    78  		i++
    79  		if i == 2 {
    80  			// Delay the second failure a bit to reset the resubscribe interval.
    81  			time.Sleep(200 * time.Millisecond)
    82  		}
    83  		if i < nfails {
    84  			return nil, errors.New("oops")
    85  		}
    86  		sub := NewSubscription(func(unsubscribed <-chan struct{}) error { return nil })
    87  		return sub, nil
    88  	})
    89  
    90  	<-sub.Err()
    91  	require.Equal(t, nfails, i)
    92  }
    93  
    94  func TestResubscribeAbort(t *testing.T) {
    95  	t.Parallel()
    96  
    97  	done := make(chan error)
    98  	sub := Resubscribe(0, func(ctx context.Context) (Subscription, error) {
    99  		select {
   100  		case <-ctx.Done():
   101  			done <- nil
   102  		case <-time.After(2 * time.Second):
   103  			done <- errors.New("context given to resubscribe function not canceled within 2s")
   104  		}
   105  		return nil, nil
   106  	})
   107  
   108  	sub.Unsubscribe()
   109  	require.NoError(t, <-done)
   110  }