lbcd/mediantime_test.go
Dave Collins b4c55aee28 Update new time tests to prevent false positives.
The new median time tests perform a comparsion of the adjusted time
returned from the median time source to the expected value.  However,
since time is always moving, it is possible the current time between the
call to the adjusted time function and the current time taken in the tests
for comparison just after the call differ by a second due to a boundary
condition.  So, this commit modifies the tests to allow for this
condition.
2014-10-11 14:53:27 -05:00

101 lines
3.6 KiB
Go

// Copyright (c) 2013-2014 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package btcchain_test
import (
"strconv"
"testing"
"time"
"github.com/conformal/btcchain"
)
// TestMedianTime tests the medianTime implementation.
func TestMedianTime(t *testing.T) {
tests := []struct {
in []int64
wantOffset int64
useDupID bool
}{
// Not enough samples must result in an offset of 0.
{in: []int64{1}, wantOffset: 0},
{in: []int64{1, 2}, wantOffset: 0},
{in: []int64{1, 2, 3}, wantOffset: 0},
{in: []int64{1, 2, 3, 4}, wantOffset: 0},
// Various number of entries. The expected offset is only
// updated on odd number of elements.
{in: []int64{-13, 57, -4, -23, -12}, wantOffset: 12},
{in: []int64{55, -13, 61, -52, 39, 55}, wantOffset: -39},
{in: []int64{-62, -58, -30, -62, 51, -30, 15}, wantOffset: 30},
{in: []int64{29, -47, 39, 54, 42, 41, 8, -33}, wantOffset: -39},
{in: []int64{37, 54, 9, -21, -56, -36, 5, -11, -39}, wantOffset: 11},
{in: []int64{57, -28, 25, -39, 9, 63, -16, 19, -60, 25}, wantOffset: -9},
{in: []int64{-5, -4, -3, -2, -1}, wantOffset: 3, useDupID: true},
// The offset stops being updated once the max number of entries
// has been reached. This is actually a bug from Bitcoin Core,
// but since the time is ultimately used as a part of the
// consensus rules, it must be mirrored.
{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52}, wantOffset: -17},
{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52, 45}, wantOffset: -17},
{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52, 45, 4}, wantOffset: -17},
// Offsets that are too far away from the local time should
// be ignored.
{in: []int64{-4201, 4202, -4203, 4204, -4205}, wantOffset: 0},
// Excerise the condition where the median offset is greater
// than the max allowed adjustment, but there is at least one
// sample that is close enough to the current time to avoid
// triggering a warning about an invalid local clock.
{in: []int64{4201, 4202, 4203, 4204, -299}, wantOffset: 0},
}
// Modify the max number of allowed median time entries for these tests.
btcchain.TstSetMaxMedianTimeEntries(10)
defer btcchain.TstSetMaxMedianTimeEntries(200)
for i, test := range tests {
filter := btcchain.NewMedianTime()
for j, offset := range test.in {
id := strconv.Itoa(j)
tOffset := time.Now().Add(time.Duration(offset) *
time.Second)
filter.AddTimeSample(id, tOffset)
// Ensure the duplicate IDs are ignored.
if test.useDupID {
// Modify the offsets to ensure the final median
// would be different if the duplicate is added.
tOffset = tOffset.Add(time.Duration(offset) *
time.Second)
filter.AddTimeSample(id, tOffset)
}
}
gotOffset := filter.Offset()
wantOffset := time.Duration(test.wantOffset) * time.Second
if gotOffset != wantOffset {
t.Errorf("Offset #%d: unexpected offset -- got %v, "+
"want %v", i, gotOffset, wantOffset)
continue
}
// Since it is possible that the time.Now call in AdjustedTime
// and the time.Now call here in the tests will be off by one
// second, allow a fudge factor to compensate.
adjustedTime := filter.AdjustedTime()
now := time.Unix(time.Now().Unix(), 0)
wantTime := now.Add(filter.Offset())
wantTime2 := now.Add(filter.Offset() - time.Second)
if !adjustedTime.Equal(wantTime) && !adjustedTime.Equal(wantTime2) {
t.Errorf("AdjustedTime #%d: unexpected result -- got %v, "+
"want %v or %v", i, adjustedTime, wantTime,
wantTime2)
continue
}
}
}