aboutsummaryrefslogblamecommitdiffstats
path: root/event/subscription_test.go
blob: 5b8a2c8ede9766c1e727d1b7b15cf6526c549400 (plain) (tree)
1
                                         

















                                                                                  
                 


                 
































































































                                                                                                          
// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package event

import (
    "context"
    "errors"
    "testing"
    "time"
)

var errInts = errors.New("error in subscribeInts")

func subscribeInts(max, fail int, c chan<- int) Subscription {
    return NewSubscription(func(quit <-chan struct{}) error {
        for i := 0; i < max; i++ {
            if i >= fail {
                return errInts
            }
            select {
            case c <- i:
            case <-quit:
                return nil
            }
        }
        return nil
    })
}

func TestNewSubscriptionError(t *testing.T) {
    t.Parallel()

    channel := make(chan int)
    sub := subscribeInts(10, 2, channel)
loop:
    for want := 0; want < 10; want++ {
        select {
        case got := <-channel:
            if got != want {
                t.Fatalf("wrong int %d, want %d", got, want)
            }
        case err := <-sub.Err():
            if err != errInts {
                t.Fatalf("wrong error: got %q, want %q", err, errInts)
            }
            if want != 2 {
                t.Fatalf("got errInts at int %d, should be received at 2", want)
            }
            break loop
        }
    }
    sub.Unsubscribe()

    err, ok := <-sub.Err()
    if err != nil {
        t.Fatal("got non-nil error after Unsubscribe")
    }
    if ok {
        t.Fatal("channel still open after Unsubscribe")
    }
}

func TestResubscribe(t *testing.T) {
    t.Parallel()

    var i int
    nfails := 6
    sub := Resubscribe(100*time.Millisecond, func(ctx context.Context) (Subscription, error) {
        // fmt.Printf("call #%d @ %v\n", i, time.Now())
        i++
        if i == 2 {
            // Delay the second failure a bit to reset the resubscribe interval.
            time.Sleep(200 * time.Millisecond)
        }
        if i < nfails {
            return nil, errors.New("oops")
        }
        sub := NewSubscription(func(unsubscribed <-chan struct{}) error { return nil })
        return sub, nil
    })

    <-sub.Err()
    if i != nfails {
        t.Fatalf("resubscribe function called %d times, want %d times", i, nfails)
    }
}

func TestResubscribeAbort(t *testing.T) {
    t.Parallel()

    done := make(chan error)
    sub := Resubscribe(0, func(ctx context.Context) (Subscription, error) {
        select {
        case <-ctx.Done():
            done <- nil
        case <-time.After(2 * time.Second):
            done <- errors.New("context given to resubscribe function not canceled within 2s")
        }
        return nil, nil
    })

    sub.Unsubscribe()
    if err := <-done; err != nil {
        t.Fatal(err)
    }
}