github.com/phillinzzz/newBsc@v1.1.6/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  	"fmt"
    23  	"reflect"
    24  	"testing"
    25  	"time"
    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  			if got != want {
    56  				t.Fatalf("wrong int %d, want %d", got, want)
    57  			}
    58  		case err := <-sub.Err():
    59  			if err != errInts {
    60  				t.Fatalf("wrong error: got %q, want %q", err, errInts)
    61  			}
    62  			if want != 2 {
    63  				t.Fatalf("got errInts at int %d, should be received at 2", want)
    64  			}
    65  			break loop
    66  		}
    67  	}
    68  	sub.Unsubscribe()
    69  
    70  	err, ok := <-sub.Err()
    71  	if err != nil {
    72  		t.Fatal("got non-nil error after Unsubscribe")
    73  	}
    74  	if ok {
    75  		t.Fatal("channel still open after Unsubscribe")
    76  	}
    77  }
    78  
    79  func TestResubscribe(t *testing.T) {
    80  	t.Parallel()
    81  
    82  	var i int
    83  	nfails := 6
    84  	sub := Resubscribe(100*time.Millisecond, func(ctx context.Context) (Subscription, error) {
    85  		// fmt.Printf("call #%d @ %v\n", i, time.Now())
    86  		i++
    87  		if i == 2 {
    88  			// Delay the second failure a bit to reset the resubscribe interval.
    89  			time.Sleep(200 * time.Millisecond)
    90  		}
    91  		if i < nfails {
    92  			return nil, errors.New("oops")
    93  		}
    94  		sub := NewSubscription(func(unsubscribed <-chan struct{}) error { return nil })
    95  		return sub, nil
    96  	})
    97  
    98  	<-sub.Err()
    99  	if i != nfails {
   100  		t.Fatalf("resubscribe function called %d times, want %d times", i, nfails)
   101  	}
   102  }
   103  
   104  func TestResubscribeAbort(t *testing.T) {
   105  	t.Parallel()
   106  
   107  	done := make(chan error, 1)
   108  	sub := Resubscribe(0, func(ctx context.Context) (Subscription, error) {
   109  		select {
   110  		case <-ctx.Done():
   111  			done <- nil
   112  		case <-time.After(2 * time.Second):
   113  			done <- errors.New("context given to resubscribe function not canceled within 2s")
   114  		}
   115  		return nil, nil
   116  	})
   117  
   118  	sub.Unsubscribe()
   119  	if err := <-done; err != nil {
   120  		t.Fatal(err)
   121  	}
   122  }
   123  
   124  func TestResubscribeWithErrorHandler(t *testing.T) {
   125  	t.Parallel()
   126  
   127  	var i int
   128  	nfails := 6
   129  	subErrs := make([]string, 0)
   130  	sub := ResubscribeErr(100*time.Millisecond, func(ctx context.Context, lastErr error) (Subscription, error) {
   131  		i++
   132  		var lastErrVal string
   133  		if lastErr != nil {
   134  			lastErrVal = lastErr.Error()
   135  		}
   136  		subErrs = append(subErrs, lastErrVal)
   137  		sub := NewSubscription(func(unsubscribed <-chan struct{}) error {
   138  			if i < nfails {
   139  				return fmt.Errorf("err-%v", i)
   140  			} else {
   141  				return nil
   142  			}
   143  		})
   144  		return sub, nil
   145  	})
   146  
   147  	<-sub.Err()
   148  	if i != nfails {
   149  		t.Fatalf("resubscribe function called %d times, want %d times", i, nfails)
   150  	}
   151  
   152  	expectedSubErrs := []string{"", "err-1", "err-2", "err-3", "err-4", "err-5"}
   153  	if !reflect.DeepEqual(subErrs, expectedSubErrs) {
   154  		t.Fatalf("unexpected subscription errors %v, want %v", subErrs, expectedSubErrs)
   155  	}
   156  }