libgo: update to go1.9

[official-gcc.git] / libgo / go / time / time_test.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package time_test

import (
        "bytes"
        "encoding/gob"
        "encoding/json"
        "fmt"
        "math/big"
        "math/rand"
        "os"
        "runtime"
        "strings"
        "testing"
        "testing/quick"
        . "time"
)

// We should be in PST/PDT, but if the time zone files are missing we
// won't be. The purpose of this test is to at least explain why some of
// the subsequent tests fail.
func TestZoneData(t *testing.T) {
        lt := Now()
        // PST is 8 hours west, PDT is 7 hours west. We could use the name but it's not unique.
        if name, off := lt.Zone(); off != -8*60*60 && off != -7*60*60 {
                t.Errorf("Unable to find US Pacific time zone data for testing; time zone is %q offset %d", name, off)
                t.Error("Likely problem: the time zone files have not been installed.")
        }
}

// parsedTime is the struct representing a parsed time value.
type parsedTime struct {
        Year                 int
        Month                Month
        Day                  int
        Hour, Minute, Second int // 15:04:05 is 15, 4, 5.
        Nanosecond           int // Fractional second.
        Weekday              Weekday
        ZoneOffset           int    // seconds east of UTC, e.g. -7*60*60 for -0700
        Zone                 string // e.g., "MST"
}

type TimeTest struct {
        seconds int64
        golden  parsedTime
}

var utctests = []TimeTest{
        {0, parsedTime{1970, January, 1, 0, 0, 0, 0, Thursday, 0, "UTC"}},
        {1221681866, parsedTime{2008, September, 17, 20, 4, 26, 0, Wednesday, 0, "UTC"}},
        {-1221681866, parsedTime{1931, April, 16, 3, 55, 34, 0, Thursday, 0, "UTC"}},
        {-11644473600, parsedTime{1601, January, 1, 0, 0, 0, 0, Monday, 0, "UTC"}},
        {599529660, parsedTime{1988, December, 31, 0, 1, 0, 0, Saturday, 0, "UTC"}},
        {978220860, parsedTime{2000, December, 31, 0, 1, 0, 0, Sunday, 0, "UTC"}},
}

var nanoutctests = []TimeTest{
        {0, parsedTime{1970, January, 1, 0, 0, 0, 1e8, Thursday, 0, "UTC"}},
        {1221681866, parsedTime{2008, September, 17, 20, 4, 26, 2e8, Wednesday, 0, "UTC"}},
}

var localtests = []TimeTest{
        {0, parsedTime{1969, December, 31, 16, 0, 0, 0, Wednesday, -8 * 60 * 60, "PST"}},
        {1221681866, parsedTime{2008, September, 17, 13, 4, 26, 0, Wednesday, -7 * 60 * 60, "PDT"}},
}

var nanolocaltests = []TimeTest{
        {0, parsedTime{1969, December, 31, 16, 0, 0, 1e8, Wednesday, -8 * 60 * 60, "PST"}},
        {1221681866, parsedTime{2008, September, 17, 13, 4, 26, 3e8, Wednesday, -7 * 60 * 60, "PDT"}},
}

func same(t Time, u *parsedTime) bool {
        // Check aggregates.
        year, month, day := t.Date()
        hour, min, sec := t.Clock()
        name, offset := t.Zone()
        if year != u.Year || month != u.Month || day != u.Day ||
                hour != u.Hour || min != u.Minute || sec != u.Second ||
                name != u.Zone || offset != u.ZoneOffset {
                return false
        }
        // Check individual entries.
        return t.Year() == u.Year &&
                t.Month() == u.Month &&
                t.Day() == u.Day &&
                t.Hour() == u.Hour &&
                t.Minute() == u.Minute &&
                t.Second() == u.Second &&
                t.Nanosecond() == u.Nanosecond &&
                t.Weekday() == u.Weekday
}

func TestSecondsToUTC(t *testing.T) {
        for _, test := range utctests {
                sec := test.seconds
                golden := &test.golden
                tm := Unix(sec, 0).UTC()
                newsec := tm.Unix()
                if newsec != sec {
                        t.Errorf("SecondsToUTC(%d).Seconds() = %d", sec, newsec)
                }
                if !same(tm, golden) {
                        t.Errorf("SecondsToUTC(%d):  // %#v", sec, tm)
                        t.Errorf("  want=%+v", *golden)
                        t.Errorf("  have=%v", tm.Format(RFC3339+" MST"))
                }
        }
}

func TestNanosecondsToUTC(t *testing.T) {
        for _, test := range nanoutctests {
                golden := &test.golden
                nsec := test.seconds*1e9 + int64(golden.Nanosecond)
                tm := Unix(0, nsec).UTC()
                newnsec := tm.Unix()*1e9 + int64(tm.Nanosecond())
                if newnsec != nsec {
                        t.Errorf("NanosecondsToUTC(%d).Nanoseconds() = %d", nsec, newnsec)
                }
                if !same(tm, golden) {
                        t.Errorf("NanosecondsToUTC(%d):", nsec)
                        t.Errorf("  want=%+v", *golden)
                        t.Errorf("  have=%+v", tm.Format(RFC3339+" MST"))
                }
        }
}

func TestSecondsToLocalTime(t *testing.T) {
        for _, test := range localtests {
                sec := test.seconds
                golden := &test.golden
                tm := Unix(sec, 0)
                newsec := tm.Unix()
                if newsec != sec {
                        t.Errorf("SecondsToLocalTime(%d).Seconds() = %d", sec, newsec)
                }
                if !same(tm, golden) {
                        t.Errorf("SecondsToLocalTime(%d):", sec)
                        t.Errorf("  want=%+v", *golden)
                        t.Errorf("  have=%+v", tm.Format(RFC3339+" MST"))
                }
        }
}

func TestNanosecondsToLocalTime(t *testing.T) {
        for _, test := range nanolocaltests {
                golden := &test.golden
                nsec := test.seconds*1e9 + int64(golden.Nanosecond)
                tm := Unix(0, nsec)
                newnsec := tm.Unix()*1e9 + int64(tm.Nanosecond())
                if newnsec != nsec {
                        t.Errorf("NanosecondsToLocalTime(%d).Seconds() = %d", nsec, newnsec)
                }
                if !same(tm, golden) {
                        t.Errorf("NanosecondsToLocalTime(%d):", nsec)
                        t.Errorf("  want=%+v", *golden)
                        t.Errorf("  have=%+v", tm.Format(RFC3339+" MST"))
                }
        }
}

func TestSecondsToUTCAndBack(t *testing.T) {
        f := func(sec int64) bool { return Unix(sec, 0).UTC().Unix() == sec }
        f32 := func(sec int32) bool { return f(int64(sec)) }
        cfg := &quick.Config{MaxCount: 10000}

        // Try a reasonable date first, then the huge ones.
        if err := quick.Check(f32, cfg); err != nil {
                t.Fatal(err)
        }
        if err := quick.Check(f, cfg); err != nil {
                t.Fatal(err)
        }
}

func TestNanosecondsToUTCAndBack(t *testing.T) {
        f := func(nsec int64) bool {
                t := Unix(0, nsec).UTC()
                ns := t.Unix()*1e9 + int64(t.Nanosecond())
                return ns == nsec
        }
        f32 := func(nsec int32) bool { return f(int64(nsec)) }
        cfg := &quick.Config{MaxCount: 10000}

        // Try a small date first, then the large ones. (The span is only a few hundred years
        // for nanoseconds in an int64.)
        if err := quick.Check(f32, cfg); err != nil {
                t.Fatal(err)
        }
        if err := quick.Check(f, cfg); err != nil {
                t.Fatal(err)
        }
}

// The time routines provide no way to get absolute time
// (seconds since zero), but we need it to compute the right
// answer for bizarre roundings like "to the nearest 3 ns".
// Compute as t - year1 = (t - 1970) + (1970 - 2001) + (2001 - 1).
// t - 1970 is returned by Unix and Nanosecond.
// 1970 - 2001 is -(31*365+8)*86400 = -978307200 seconds.
// 2001 - 1 is 2000*365.2425*86400 = 63113904000 seconds.
const unixToZero = -978307200 + 63113904000

// abs returns the absolute time stored in t, as seconds and nanoseconds.
func abs(t Time) (sec, nsec int64) {
        unix := t.Unix()
        nano := t.Nanosecond()
        return unix + unixToZero, int64(nano)
}

// absString returns abs as a decimal string.
func absString(t Time) string {
        sec, nsec := abs(t)
        if sec < 0 {
                sec = -sec
                nsec = -nsec
                if nsec < 0 {
                        nsec += 1e9
                        sec--
                }
                return fmt.Sprintf("-%d%09d", sec, nsec)
        }
        return fmt.Sprintf("%d%09d", sec, nsec)
}

var truncateRoundTests = []struct {
        t Time
        d Duration
}{
        {Date(-1, January, 1, 12, 15, 30, 5e8, UTC), 3},
        {Date(-1, January, 1, 12, 15, 31, 5e8, UTC), 3},
        {Date(2012, January, 1, 12, 15, 30, 5e8, UTC), Second},
        {Date(2012, January, 1, 12, 15, 31, 5e8, UTC), Second},
        {Unix(-19012425939, 649146258), 7435029458905025217}, // 5.8*d rounds to 6*d, but .8*d+.8*d < 0 < d
}

func TestTruncateRound(t *testing.T) {
        var (
                bsec  = new(big.Int)
                bnsec = new(big.Int)
                bd    = new(big.Int)
                bt    = new(big.Int)
                br    = new(big.Int)
                bq    = new(big.Int)
                b1e9  = new(big.Int)
        )

        b1e9.SetInt64(1e9)

        testOne := func(ti, tns, di int64) bool {
                t0 := Unix(ti, int64(tns)).UTC()
                d := Duration(di)
                if d < 0 {
                        d = -d
                }
                if d <= 0 {
                        d = 1
                }

                // Compute bt = absolute nanoseconds.
                sec, nsec := abs(t0)
                bsec.SetInt64(sec)
                bnsec.SetInt64(nsec)
                bt.Mul(bsec, b1e9)
                bt.Add(bt, bnsec)

                // Compute quotient and remainder mod d.
                bd.SetInt64(int64(d))
                bq.DivMod(bt, bd, br)

                // To truncate, subtract remainder.
                // br is < d, so it fits in an int64.
                r := br.Int64()
                t1 := t0.Add(-Duration(r))

                // Check that time.Truncate works.
                if trunc := t0.Truncate(d); trunc != t1 {
                        t.Errorf("Time.Truncate(%s, %s) = %s, want %s\n"+
                                "%v trunc %v =\n%v want\n%v",
                                t0.Format(RFC3339Nano), d, trunc, t1.Format(RFC3339Nano),
                                absString(t0), int64(d), absString(trunc), absString(t1))
                        return false
                }

                // To round, add d back if remainder r > d/2 or r == exactly d/2.
                // The commented out code would round half to even instead of up,
                // but that makes it time-zone dependent, which is a bit strange.
                if r > int64(d)/2 || r+r == int64(d) /*&& bq.Bit(0) == 1*/ {
                        t1 = t1.Add(Duration(d))
                }

                // Check that time.Round works.
                if rnd := t0.Round(d); rnd != t1 {
                        t.Errorf("Time.Round(%s, %s) = %s, want %s\n"+
                                "%v round %v =\n%v want\n%v",
                                t0.Format(RFC3339Nano), d, rnd, t1.Format(RFC3339Nano),
                                absString(t0), int64(d), absString(rnd), absString(t1))
                        return false
                }
                return true
        }

        // manual test cases
        for _, tt := range truncateRoundTests {
                testOne(tt.t.Unix(), int64(tt.t.Nanosecond()), int64(tt.d))
        }

        // exhaustive near 0
        for i := 0; i < 100; i++ {
                for j := 1; j < 100; j++ {
                        testOne(unixToZero, int64(i), int64(j))
                        testOne(unixToZero, -int64(i), int64(j))
                        if t.Failed() {
                                return
                        }
                }
        }

        if t.Failed() {
                return
        }

        // randomly generated test cases
        cfg := &quick.Config{MaxCount: 100000}
        if testing.Short() {
                cfg.MaxCount = 1000
        }

        // divisors of Second
        f1 := func(ti int64, tns int32, logdi int32) bool {
                d := Duration(1)
                a, b := uint(logdi%9), (logdi>>16)%9
                d <<= a
                for i := 0; i < int(b); i++ {
                        d *= 5
                }
                return testOne(ti, int64(tns), int64(d))
        }
        quick.Check(f1, cfg)

        // multiples of Second
        f2 := func(ti int64, tns int32, di int32) bool {
                d := Duration(di) * Second
                if d < 0 {
                        d = -d
                }
                return testOne(ti, int64(tns), int64(d))
        }
        quick.Check(f2, cfg)

        // halfway cases
        f3 := func(tns, di int64) bool {
                di &= 0xfffffffe
                if di == 0 {
                        di = 2
                }
                tns -= tns % di
                if tns < 0 {
                        tns += di / 2
                } else {
                        tns -= di / 2
                }
                return testOne(0, tns, di)
        }
        quick.Check(f3, cfg)

        // full generality
        f4 := func(ti int64, tns int32, di int64) bool {
                return testOne(ti, int64(tns), di)
        }
        quick.Check(f4, cfg)
}

type ISOWeekTest struct {
        year       int // year
        month, day int // month and day
        yex        int // expected year
        wex        int // expected week
}

var isoWeekTests = []ISOWeekTest{
        {1981, 1, 1, 1981, 1}, {1982, 1, 1, 1981, 53}, {1983, 1, 1, 1982, 52},
        {1984, 1, 1, 1983, 52}, {1985, 1, 1, 1985, 1}, {1986, 1, 1, 1986, 1},
        {1987, 1, 1, 1987, 1}, {1988, 1, 1, 1987, 53}, {1989, 1, 1, 1988, 52},
        {1990, 1, 1, 1990, 1}, {1991, 1, 1, 1991, 1}, {1992, 1, 1, 1992, 1},
        {1993, 1, 1, 1992, 53}, {1994, 1, 1, 1993, 52}, {1995, 1, 2, 1995, 1},
        {1996, 1, 1, 1996, 1}, {1996, 1, 7, 1996, 1}, {1996, 1, 8, 1996, 2},
        {1997, 1, 1, 1997, 1}, {1998, 1, 1, 1998, 1}, {1999, 1, 1, 1998, 53},
        {2000, 1, 1, 1999, 52}, {2001, 1, 1, 2001, 1}, {2002, 1, 1, 2002, 1},
        {2003, 1, 1, 2003, 1}, {2004, 1, 1, 2004, 1}, {2005, 1, 1, 2004, 53},
        {2006, 1, 1, 2005, 52}, {2007, 1, 1, 2007, 1}, {2008, 1, 1, 2008, 1},
        {2009, 1, 1, 2009, 1}, {2010, 1, 1, 2009, 53}, {2010, 1, 1, 2009, 53},
        {2011, 1, 1, 2010, 52}, {2011, 1, 2, 2010, 52}, {2011, 1, 3, 2011, 1},
        {2011, 1, 4, 2011, 1}, {2011, 1, 5, 2011, 1}, {2011, 1, 6, 2011, 1},
        {2011, 1, 7, 2011, 1}, {2011, 1, 8, 2011, 1}, {2011, 1, 9, 2011, 1},
        {2011, 1, 10, 2011, 2}, {2011, 1, 11, 2011, 2}, {2011, 6, 12, 2011, 23},
        {2011, 6, 13, 2011, 24}, {2011, 12, 25, 2011, 51}, {2011, 12, 26, 2011, 52},
        {2011, 12, 27, 2011, 52}, {2011, 12, 28, 2011, 52}, {2011, 12, 29, 2011, 52},
        {2011, 12, 30, 2011, 52}, {2011, 12, 31, 2011, 52}, {1995, 1, 1, 1994, 52},
        {2012, 1, 1, 2011, 52}, {2012, 1, 2, 2012, 1}, {2012, 1, 8, 2012, 1},
        {2012, 1, 9, 2012, 2}, {2012, 12, 23, 2012, 51}, {2012, 12, 24, 2012, 52},
        {2012, 12, 30, 2012, 52}, {2012, 12, 31, 2013, 1}, {2013, 1, 1, 2013, 1},
        {2013, 1, 6, 2013, 1}, {2013, 1, 7, 2013, 2}, {2013, 12, 22, 2013, 51},
        {2013, 12, 23, 2013, 52}, {2013, 12, 29, 2013, 52}, {2013, 12, 30, 2014, 1},
        {2014, 1, 1, 2014, 1}, {2014, 1, 5, 2014, 1}, {2014, 1, 6, 2014, 2},
        {2015, 1, 1, 2015, 1}, {2016, 1, 1, 2015, 53}, {2017, 1, 1, 2016, 52},
        {2018, 1, 1, 2018, 1}, {2019, 1, 1, 2019, 1}, {2020, 1, 1, 2020, 1},
        {2021, 1, 1, 2020, 53}, {2022, 1, 1, 2021, 52}, {2023, 1, 1, 2022, 52},
        {2024, 1, 1, 2024, 1}, {2025, 1, 1, 2025, 1}, {2026, 1, 1, 2026, 1},
        {2027, 1, 1, 2026, 53}, {2028, 1, 1, 2027, 52}, {2029, 1, 1, 2029, 1},
        {2030, 1, 1, 2030, 1}, {2031, 1, 1, 2031, 1}, {2032, 1, 1, 2032, 1},
        {2033, 1, 1, 2032, 53}, {2034, 1, 1, 2033, 52}, {2035, 1, 1, 2035, 1},
        {2036, 1, 1, 2036, 1}, {2037, 1, 1, 2037, 1}, {2038, 1, 1, 2037, 53},
        {2039, 1, 1, 2038, 52}, {2040, 1, 1, 2039, 52},
}

func TestISOWeek(t *testing.T) {
        // Selected dates and corner cases
        for _, wt := range isoWeekTests {
                dt := Date(wt.year, Month(wt.month), wt.day, 0, 0, 0, 0, UTC)
                y, w := dt.ISOWeek()
                if w != wt.wex || y != wt.yex {
                        t.Errorf("got %d/%d; expected %d/%d for %d-%02d-%02d",
                                y, w, wt.yex, wt.wex, wt.year, wt.month, wt.day)
                }
        }

        // The only real invariant: Jan 04 is in week 1
        for year := 1950; year < 2100; year++ {
                if y, w := Date(year, January, 4, 0, 0, 0, 0, UTC).ISOWeek(); y != year || w != 1 {
                        t.Errorf("got %d/%d; expected %d/1 for Jan 04", y, w, year)
                }
        }
}

type YearDayTest struct {
        year, month, day int
        yday             int
}

// Test YearDay in several different scenarios
// and corner cases
var yearDayTests = []YearDayTest{
        // Non-leap-year tests
        {2007, 1, 1, 1},
        {2007, 1, 15, 15},
        {2007, 2, 1, 32},
        {2007, 2, 15, 46},
        {2007, 3, 1, 60},
        {2007, 3, 15, 74},
        {2007, 4, 1, 91},
        {2007, 12, 31, 365},

        // Leap-year tests
        {2008, 1, 1, 1},
        {2008, 1, 15, 15},
        {2008, 2, 1, 32},
        {2008, 2, 15, 46},
        {2008, 3, 1, 61},
        {2008, 3, 15, 75},
        {2008, 4, 1, 92},
        {2008, 12, 31, 366},

        // Looks like leap-year (but isn't) tests
        {1900, 1, 1, 1},
        {1900, 1, 15, 15},
        {1900, 2, 1, 32},
        {1900, 2, 15, 46},
        {1900, 3, 1, 60},
        {1900, 3, 15, 74},
        {1900, 4, 1, 91},
        {1900, 12, 31, 365},

        // Year one tests (non-leap)
        {1, 1, 1, 1},
        {1, 1, 15, 15},
        {1, 2, 1, 32},
        {1, 2, 15, 46},
        {1, 3, 1, 60},
        {1, 3, 15, 74},
        {1, 4, 1, 91},
        {1, 12, 31, 365},

        // Year minus one tests (non-leap)
        {-1, 1, 1, 1},
        {-1, 1, 15, 15},
        {-1, 2, 1, 32},
        {-1, 2, 15, 46},
        {-1, 3, 1, 60},
        {-1, 3, 15, 74},
        {-1, 4, 1, 91},
        {-1, 12, 31, 365},

        // 400 BC tests (leap-year)
        {-400, 1, 1, 1},
        {-400, 1, 15, 15},
        {-400, 2, 1, 32},
        {-400, 2, 15, 46},
        {-400, 3, 1, 61},
        {-400, 3, 15, 75},
        {-400, 4, 1, 92},
        {-400, 12, 31, 366},

        // Special Cases

        // Gregorian calendar change (no effect)
        {1582, 10, 4, 277},
        {1582, 10, 15, 288},
}

// Check to see if YearDay is location sensitive
var yearDayLocations = []*Location{
        FixedZone("UTC-8", -8*60*60),
        FixedZone("UTC-4", -4*60*60),
        UTC,
        FixedZone("UTC+4", 4*60*60),
        FixedZone("UTC+8", 8*60*60),
}

func TestYearDay(t *testing.T) {
        for _, loc := range yearDayLocations {
                for _, ydt := range yearDayTests {
                        dt := Date(ydt.year, Month(ydt.month), ydt.day, 0, 0, 0, 0, loc)
                        yday := dt.YearDay()
                        if yday != ydt.yday {
                                t.Errorf("got %d, expected %d for %d-%02d-%02d in %v",
                                        yday, ydt.yday, ydt.year, ydt.month, ydt.day, loc)
                        }
                }
        }
}

var durationTests = []struct {
        str string
        d   Duration
}{
        {"0s", 0},
        {"1ns", 1 * Nanosecond},
        {"1.1µs", 1100 * Nanosecond},
        {"2.2ms", 2200 * Microsecond},
        {"3.3s", 3300 * Millisecond},
        {"4m5s", 4*Minute + 5*Second},
        {"4m5.001s", 4*Minute + 5001*Millisecond},
        {"5h6m7.001s", 5*Hour + 6*Minute + 7001*Millisecond},
        {"8m0.000000001s", 8*Minute + 1*Nanosecond},
        {"2562047h47m16.854775807s", 1<<63 - 1},
        {"-2562047h47m16.854775808s", -1 << 63},
}

func TestDurationString(t *testing.T) {
        for _, tt := range durationTests {
                if str := tt.d.String(); str != tt.str {
                        t.Errorf("Duration(%d).String() = %s, want %s", int64(tt.d), str, tt.str)
                }
                if tt.d > 0 {
                        if str := (-tt.d).String(); str != "-"+tt.str {
                                t.Errorf("Duration(%d).String() = %s, want %s", int64(-tt.d), str, "-"+tt.str)
                        }
                }
        }
}

var dateTests = []struct {
        year, month, day, hour, min, sec, nsec int
        z                                      *Location
        unix                                   int64
}{
        {2011, 11, 6, 1, 0, 0, 0, Local, 1320566400},   // 1:00:00 PDT
        {2011, 11, 6, 1, 59, 59, 0, Local, 1320569999}, // 1:59:59 PDT
        {2011, 11, 6, 2, 0, 0, 0, Local, 1320573600},   // 2:00:00 PST

        {2011, 3, 13, 1, 0, 0, 0, Local, 1300006800},   // 1:00:00 PST
        {2011, 3, 13, 1, 59, 59, 0, Local, 1300010399}, // 1:59:59 PST
        {2011, 3, 13, 3, 0, 0, 0, Local, 1300010400},   // 3:00:00 PDT
        {2011, 3, 13, 2, 30, 0, 0, Local, 1300008600},  // 2:30:00 PDT ≡ 1:30 PST

        // Many names for Fri Nov 18 7:56:35 PST 2011
        {2011, 11, 18, 7, 56, 35, 0, Local, 1321631795},                 // Nov 18 7:56:35
        {2011, 11, 19, -17, 56, 35, 0, Local, 1321631795},               // Nov 19 -17:56:35
        {2011, 11, 17, 31, 56, 35, 0, Local, 1321631795},                // Nov 17 31:56:35
        {2011, 11, 18, 6, 116, 35, 0, Local, 1321631795},                // Nov 18 6:116:35
        {2011, 10, 49, 7, 56, 35, 0, Local, 1321631795},                 // Oct 49 7:56:35
        {2011, 11, 18, 7, 55, 95, 0, Local, 1321631795},                 // Nov 18 7:55:95
        {2011, 11, 18, 7, 56, 34, 1e9, Local, 1321631795},               // Nov 18 7:56:34 + 10⁹ns
        {2011, 12, -12, 7, 56, 35, 0, Local, 1321631795},                // Dec -21 7:56:35
        {2012, 1, -43, 7, 56, 35, 0, Local, 1321631795},                 // Jan -52 7:56:35 2012
        {2012, int(January - 2), 18, 7, 56, 35, 0, Local, 1321631795},   // (Jan-2) 18 7:56:35 2012
        {2010, int(December + 11), 18, 7, 56, 35, 0, Local, 1321631795}, // (Dec+11) 18 7:56:35 2010
}

func TestDate(t *testing.T) {
        for _, tt := range dateTests {
                time := Date(tt.year, Month(tt.month), tt.day, tt.hour, tt.min, tt.sec, tt.nsec, tt.z)
                want := Unix(tt.unix, 0)
                if !time.Equal(want) {
                        t.Errorf("Date(%d, %d, %d, %d, %d, %d, %d, %s) = %v, want %v",
                                tt.year, tt.month, tt.day, tt.hour, tt.min, tt.sec, tt.nsec, tt.z,
                                time, want)
                }
        }
}

// Several ways of getting from
// Fri Nov 18 7:56:35 PST 2011
// to
// Thu Mar 19 7:56:35 PST 2016
var addDateTests = []struct {
        years, months, days int
}{
        {4, 4, 1},
        {3, 16, 1},
        {3, 15, 30},
        {5, -6, -18 - 30 - 12},
}

func TestAddDate(t *testing.T) {
        t0 := Date(2011, 11, 18, 7, 56, 35, 0, UTC)
        t1 := Date(2016, 3, 19, 7, 56, 35, 0, UTC)
        for _, at := range addDateTests {
                time := t0.AddDate(at.years, at.months, at.days)
                if !time.Equal(t1) {
                        t.Errorf("AddDate(%d, %d, %d) = %v, want %v",
                                at.years, at.months, at.days,
                                time, t1)
                }
        }
}

var daysInTests = []struct {
        year, month, di int
}{
        {2011, 1, 31},  // January, first month, 31 days
        {2011, 2, 28},  // February, non-leap year, 28 days
        {2012, 2, 29},  // February, leap year, 29 days
        {2011, 6, 30},  // June, 30 days
        {2011, 12, 31}, // December, last month, 31 days
}

func TestDaysIn(t *testing.T) {
        // The daysIn function is not exported.
        // Test the daysIn function via the `var DaysIn = daysIn`
        // statement in the internal_test.go file.
        for _, tt := range daysInTests {
                di := DaysIn(Month(tt.month), tt.year)
                if di != tt.di {
                        t.Errorf("got %d; expected %d for %d-%02d",
                                di, tt.di, tt.year, tt.month)
                }
        }
}

func TestAddToExactSecond(t *testing.T) {
        // Add an amount to the current time to round it up to the next exact second.
        // This test checks that the nsec field still lies within the range [0, 999999999].
        t1 := Now()
        t2 := t1.Add(Second - Duration(t1.Nanosecond()))
        sec := (t1.Second() + 1) % 60
        if t2.Second() != sec || t2.Nanosecond() != 0 {
                t.Errorf("sec = %d, nsec = %d, want sec = %d, nsec = 0", t2.Second(), t2.Nanosecond(), sec)
        }
}

func equalTimeAndZone(a, b Time) bool {
        aname, aoffset := a.Zone()
        bname, boffset := b.Zone()
        return a.Equal(b) && aoffset == boffset && aname == bname
}

var gobTests = []Time{
        Date(0, 1, 2, 3, 4, 5, 6, UTC),
        Date(7, 8, 9, 10, 11, 12, 13, FixedZone("", 0)),
        Unix(81985467080890095, 0x76543210), // Time.sec: 0x0123456789ABCDEF
        {}, // nil location
        Date(1, 2, 3, 4, 5, 6, 7, FixedZone("", 32767*60)),
        Date(1, 2, 3, 4, 5, 6, 7, FixedZone("", -32768*60)),
}

func TestTimeGob(t *testing.T) {
        var b bytes.Buffer
        enc := gob.NewEncoder(&b)
        dec := gob.NewDecoder(&b)
        for _, tt := range gobTests {
                var gobtt Time
                if err := enc.Encode(&tt); err != nil {
                        t.Errorf("%v gob Encode error = %q, want nil", tt, err)
                } else if err := dec.Decode(&gobtt); err != nil {
                        t.Errorf("%v gob Decode error = %q, want nil", tt, err)
                } else if !equalTimeAndZone(gobtt, tt) {
                        t.Errorf("Decoded time = %v, want %v", gobtt, tt)
                }
                b.Reset()
        }
}

var invalidEncodingTests = []struct {
        bytes []byte
        want  string
}{
        {[]byte{}, "Time.UnmarshalBinary: no data"},
        {[]byte{0, 2, 3}, "Time.UnmarshalBinary: unsupported version"},
        {[]byte{1, 2, 3}, "Time.UnmarshalBinary: invalid length"},
}

func TestInvalidTimeGob(t *testing.T) {
        for _, tt := range invalidEncodingTests {
                var ignored Time
                err := ignored.GobDecode(tt.bytes)
                if err == nil || err.Error() != tt.want {
                        t.Errorf("time.GobDecode(%#v) error = %v, want %v", tt.bytes, err, tt.want)
                }
                err = ignored.UnmarshalBinary(tt.bytes)
                if err == nil || err.Error() != tt.want {
                        t.Errorf("time.UnmarshalBinary(%#v) error = %v, want %v", tt.bytes, err, tt.want)
                }
        }
}

var notEncodableTimes = []struct {
        time Time
        want string
}{
        {Date(0, 1, 2, 3, 4, 5, 6, FixedZone("", 1)), "Time.MarshalBinary: zone offset has fractional minute"},
        {Date(0, 1, 2, 3, 4, 5, 6, FixedZone("", -1*60)), "Time.MarshalBinary: unexpected zone offset"},
        {Date(0, 1, 2, 3, 4, 5, 6, FixedZone("", -32769*60)), "Time.MarshalBinary: unexpected zone offset"},
        {Date(0, 1, 2, 3, 4, 5, 6, FixedZone("", 32768*60)), "Time.MarshalBinary: unexpected zone offset"},
}

func TestNotGobEncodableTime(t *testing.T) {
        for _, tt := range notEncodableTimes {
                _, err := tt.time.GobEncode()
                if err == nil || err.Error() != tt.want {
                        t.Errorf("%v GobEncode error = %v, want %v", tt.time, err, tt.want)
                }
                _, err = tt.time.MarshalBinary()
                if err == nil || err.Error() != tt.want {
                        t.Errorf("%v MarshalBinary error = %v, want %v", tt.time, err, tt.want)
                }
        }
}

var jsonTests = []struct {
        time Time
        json string
}{
        {Date(9999, 4, 12, 23, 20, 50, 520*1e6, UTC), `"9999-04-12T23:20:50.52Z"`},
        {Date(1996, 12, 19, 16, 39, 57, 0, Local), `"1996-12-19T16:39:57-08:00"`},
        {Date(0, 1, 1, 0, 0, 0, 1, FixedZone("", 1*60)), `"0000-01-01T00:00:00.000000001+00:01"`},
}

func TestTimeJSON(t *testing.T) {
        for _, tt := range jsonTests {
                var jsonTime Time

                if jsonBytes, err := json.Marshal(tt.time); err != nil {
                        t.Errorf("%v json.Marshal error = %v, want nil", tt.time, err)
                } else if string(jsonBytes) != tt.json {
                        t.Errorf("%v JSON = %#q, want %#q", tt.time, string(jsonBytes), tt.json)
                } else if err = json.Unmarshal(jsonBytes, &jsonTime); err != nil {
                        t.Errorf("%v json.Unmarshal error = %v, want nil", tt.time, err)
                } else if !equalTimeAndZone(jsonTime, tt.time) {
                        t.Errorf("Unmarshaled time = %v, want %v", jsonTime, tt.time)
                }
        }
}

func TestInvalidTimeJSON(t *testing.T) {
        var tt Time
        err := json.Unmarshal([]byte(`{"now is the time":"buddy"}`), &tt)
        _, isParseErr := err.(*ParseError)
        if !isParseErr {
                t.Errorf("expected *time.ParseError unmarshaling JSON, got %v", err)
        }
}

var notJSONEncodableTimes = []struct {
        time Time
        want string
}{
        {Date(10000, 1, 1, 0, 0, 0, 0, UTC), "Time.MarshalJSON: year outside of range [0,9999]"},
        {Date(-1, 1, 1, 0, 0, 0, 0, UTC), "Time.MarshalJSON: year outside of range [0,9999]"},
}

func TestNotJSONEncodableTime(t *testing.T) {
        for _, tt := range notJSONEncodableTimes {
                _, err := tt.time.MarshalJSON()
                if err == nil || err.Error() != tt.want {
                        t.Errorf("%v MarshalJSON error = %v, want %v", tt.time, err, tt.want)
                }
        }
}

var parseDurationTests = []struct {
        in   string
        ok   bool
        want Duration
}{
        // simple
        {"0", true, 0},
        {"5s", true, 5 * Second},
        {"30s", true, 30 * Second},
        {"1478s", true, 1478 * Second},
        // sign
        {"-5s", true, -5 * Second},
        {"+5s", true, 5 * Second},
        {"-0", true, 0},
        {"+0", true, 0},
        // decimal
        {"5.0s", true, 5 * Second},
        {"5.6s", true, 5*Second + 600*Millisecond},
        {"5.s", true, 5 * Second},
        {".5s", true, 500 * Millisecond},
        {"1.0s", true, 1 * Second},
        {"1.00s", true, 1 * Second},
        {"1.004s", true, 1*Second + 4*Millisecond},
        {"1.0040s", true, 1*Second + 4*Millisecond},
        {"100.00100s", true, 100*Second + 1*Millisecond},
        // different units
        {"10ns", true, 10 * Nanosecond},
        {"11us", true, 11 * Microsecond},
        {"12µs", true, 12 * Microsecond}, // U+00B5
        {"12μs", true, 12 * Microsecond}, // U+03BC
        {"13ms", true, 13 * Millisecond},
        {"14s", true, 14 * Second},
        {"15m", true, 15 * Minute},
        {"16h", true, 16 * Hour},
        // composite durations
        {"3h30m", true, 3*Hour + 30*Minute},
        {"10.5s4m", true, 4*Minute + 10*Second + 500*Millisecond},
        {"-2m3.4s", true, -(2*Minute + 3*Second + 400*Millisecond)},
        {"1h2m3s4ms5us6ns", true, 1*Hour + 2*Minute + 3*Second + 4*Millisecond + 5*Microsecond + 6*Nanosecond},
        {"39h9m14.425s", true, 39*Hour + 9*Minute + 14*Second + 425*Millisecond},
        // large value
        {"52763797000ns", true, 52763797000 * Nanosecond},
        // more than 9 digits after decimal point, see https://golang.org/issue/6617
        {"0.3333333333333333333h", true, 20 * Minute},
        // 9007199254740993 = 1<<53+1 cannot be stored precisely in a float64
        {"9007199254740993ns", true, (1<<53 + 1) * Nanosecond},
        // largest duration that can be represented by int64 in nanoseconds
        {"9223372036854775807ns", true, (1<<63 - 1) * Nanosecond},
        {"9223372036854775.807us", true, (1<<63 - 1) * Nanosecond},
        {"9223372036s854ms775us807ns", true, (1<<63 - 1) * Nanosecond},
        // large negative value
        {"-9223372036854775807ns", true, -1<<63 + 1*Nanosecond},
        // huge string; issue 15011.
        {"0.100000000000000000000h", true, 6 * Minute},
        // This value tests the first overflow check in leadingFraction.
        {"0.830103483285477580700h", true, 49*Minute + 48*Second + 372539827*Nanosecond},

        // errors
        {"", false, 0},
        {"3", false, 0},
        {"-", false, 0},
        {"s", false, 0},
        {".", false, 0},
        {"-.", false, 0},
        {".s", false, 0},
        {"+.s", false, 0},
        {"3000000h", false, 0},                  // overflow
        {"9223372036854775808ns", false, 0},     // overflow
        {"9223372036854775.808us", false, 0},    // overflow
        {"9223372036854ms775us808ns", false, 0}, // overflow
        // largest negative value of type int64 in nanoseconds should fail
        // see https://go-review.googlesource.com/#/c/2461/
        {"-9223372036854775808ns", false, 0},
}

func TestParseDuration(t *testing.T) {
        for _, tc := range parseDurationTests {
                d, err := ParseDuration(tc.in)
                if tc.ok && (err != nil || d != tc.want) {
                        t.Errorf("ParseDuration(%q) = %v, %v, want %v, nil", tc.in, d, err, tc.want)
                } else if !tc.ok && err == nil {
                        t.Errorf("ParseDuration(%q) = _, nil, want _, non-nil", tc.in)
                }
        }
}

func TestParseDurationRoundTrip(t *testing.T) {
        for i := 0; i < 100; i++ {
                // Resolutions finer than milliseconds will result in
                // imprecise round-trips.
                d0 := Duration(rand.Int31()) * Millisecond
                s := d0.String()
                d1, err := ParseDuration(s)
                if err != nil || d0 != d1 {
                        t.Errorf("round-trip failed: %d => %q => %d, %v", d0, s, d1, err)
                }
        }
}

// golang.org/issue/4622
func TestLocationRace(t *testing.T) {
        ResetLocalOnceForTest() // reset the Once to trigger the race

        c := make(chan string, 1)
        go func() {
                c <- Now().String()
        }()
        _ = Now().String()
        <-c
        Sleep(100 * Millisecond)

        // Back to Los Angeles for subsequent tests:
        ForceUSPacificForTesting()
}

var (
        t Time
        u int64
)

var mallocTest = []struct {
        count int
        desc  string
        fn    func()
}{
        {0, `time.Now()`, func() { t = Now() }},
        {0, `time.Now().UnixNano()`, func() { u = Now().UnixNano() }},
}

func TestCountMallocs(t *testing.T) {
        if testing.Short() {
                t.Skip("skipping malloc count in short mode")
        }
        if runtime.GOMAXPROCS(0) > 1 {
                t.Skip("skipping; GOMAXPROCS>1")
        }
        for _, mt := range mallocTest {
                allocs := int(testing.AllocsPerRun(100, mt.fn))
                if allocs > mt.count {
                        t.Errorf("%s: %d allocs, want %d", mt.desc, allocs, mt.count)
                }
        }
}

func TestLoadFixed(t *testing.T) {
        // Issue 4064: handle locations without any zone transitions.
        loc, err := LoadLocation("Etc/GMT+1")
        if err != nil {
                t.Fatal(err)
        }

        // The tzdata name Etc/GMT+1 uses "east is negative",
        // but Go and most other systems use "east is positive".
        // So GMT+1 corresponds to -3600 in the Go zone, not +3600.
        name, offset := Now().In(loc).Zone()
        // The zone abbreviation is "-01" since tzdata-2016g, and "GMT+1"
        // on earlier versions; we accept both. (Issue #17276).
        if !(name == "GMT+1" || name == "-01") || offset != -1*60*60 {
                t.Errorf("Now().In(loc).Zone() = %q, %d, want %q or %q, %d",
                        name, offset, "GMT+1", "-01", -1*60*60)
        }
}

const (
        minDuration Duration = -1 << 63
        maxDuration Duration = 1<<63 - 1
)

var subTests = []struct {
        t Time
        u Time
        d Duration
}{
        {Time{}, Time{}, Duration(0)},
        {Date(2009, 11, 23, 0, 0, 0, 1, UTC), Date(2009, 11, 23, 0, 0, 0, 0, UTC), Duration(1)},
        {Date(2009, 11, 23, 0, 0, 0, 0, UTC), Date(2009, 11, 24, 0, 0, 0, 0, UTC), -24 * Hour},
        {Date(2009, 11, 24, 0, 0, 0, 0, UTC), Date(2009, 11, 23, 0, 0, 0, 0, UTC), 24 * Hour},
        {Date(-2009, 11, 24, 0, 0, 0, 0, UTC), Date(-2009, 11, 23, 0, 0, 0, 0, UTC), 24 * Hour},
        {Time{}, Date(2109, 11, 23, 0, 0, 0, 0, UTC), Duration(minDuration)},
        {Date(2109, 11, 23, 0, 0, 0, 0, UTC), Time{}, Duration(maxDuration)},
        {Time{}, Date(-2109, 11, 23, 0, 0, 0, 0, UTC), Duration(maxDuration)},
        {Date(-2109, 11, 23, 0, 0, 0, 0, UTC), Time{}, Duration(minDuration)},
        {Date(2290, 1, 1, 0, 0, 0, 0, UTC), Date(2000, 1, 1, 0, 0, 0, 0, UTC), 290*365*24*Hour + 71*24*Hour},
        {Date(2300, 1, 1, 0, 0, 0, 0, UTC), Date(2000, 1, 1, 0, 0, 0, 0, UTC), Duration(maxDuration)},
        {Date(2000, 1, 1, 0, 0, 0, 0, UTC), Date(2290, 1, 1, 0, 0, 0, 0, UTC), -290*365*24*Hour - 71*24*Hour},
        {Date(2000, 1, 1, 0, 0, 0, 0, UTC), Date(2300, 1, 1, 0, 0, 0, 0, UTC), Duration(minDuration)},
}

func TestSub(t *testing.T) {
        for i, st := range subTests {
                got := st.t.Sub(st.u)
                if got != st.d {
                        t.Errorf("#%d: Sub(%v, %v): got %v; want %v", i, st.t, st.u, got, st.d)
                }
        }
}

var nsDurationTests = []struct {
        d    Duration
        want int64
}{
        {Duration(-1000), -1000},
        {Duration(-1), -1},
        {Duration(1), 1},
        {Duration(1000), 1000},
}

func TestDurationNanoseconds(t *testing.T) {
        for _, tt := range nsDurationTests {
                if got := tt.d.Nanoseconds(); got != tt.want {
                        t.Errorf("d.Nanoseconds() = %d; want: %d", got, tt.want)
                }
        }
}

var secDurationTests = []struct {
        d    Duration
        want float64
}{
        {Duration(300000000), 0.3},
}

func TestDurationSeconds(t *testing.T) {
        for _, tt := range secDurationTests {
                if got := tt.d.Seconds(); got != tt.want {
                        t.Errorf("d.Seconds() = %g; want: %g", got, tt.want)
                }
        }
}

var minDurationTests = []struct {
        d    Duration
        want float64
}{
        {Duration(-60000000000), -1},
        {Duration(-1), -1 / 60e9},
        {Duration(1), 1 / 60e9},
        {Duration(60000000000), 1},
        {Duration(3000), 5e-8},
}

func TestDurationMinutes(t *testing.T) {
        for _, tt := range minDurationTests {
                if got := tt.d.Minutes(); got != tt.want {
                        t.Errorf("d.Minutes() = %g; want: %g", got, tt.want)
                }
        }
}

var hourDurationTests = []struct {
        d    Duration
        want float64
}{
        {Duration(-3600000000000), -1},
        {Duration(-1), -1 / 3600e9},
        {Duration(1), 1 / 3600e9},
        {Duration(3600000000000), 1},
        {Duration(36), 1e-11},
}

func TestDurationHours(t *testing.T) {
        for _, tt := range hourDurationTests {
                if got := tt.d.Hours(); got != tt.want {
                        t.Errorf("d.Hours() = %g; want: %g", got, tt.want)
                }
        }
}

var durationTruncateTests = []struct {
        d    Duration
        m    Duration
        want Duration
}{
        {0, Second, 0},
        {Minute, -7 * Second, Minute},
        {Minute, 0, Minute},
        {Minute, 1, Minute},
        {Minute + 10*Second, 10 * Second, Minute + 10*Second},
        {2*Minute + 10*Second, Minute, 2 * Minute},
        {10*Minute + 10*Second, 3 * Minute, 9 * Minute},
        {Minute + 10*Second, Minute + 10*Second + 1, 0},
        {Minute + 10*Second, Hour, 0},
        {-Minute, Second, -Minute},
        {-10 * Minute, 3 * Minute, -9 * Minute},
        {-10 * Minute, Hour, 0},
}

func TestDurationTruncate(t *testing.T) {
        for _, tt := range durationTruncateTests {
                if got := tt.d.Truncate(tt.m); got != tt.want {
                        t.Errorf("Duration(%s).Truncate(%s) = %s; want: %s", tt.d, tt.m, got, tt.want)
                }
        }
}

var durationRoundTests = []struct {
        d    Duration
        m    Duration
        want Duration
}{
        {0, Second, 0},
        {Minute, -11 * Second, Minute},
        {Minute, 0, Minute},
        {Minute, 1, Minute},
        {2 * Minute, Minute, 2 * Minute},
        {2*Minute + 10*Second, Minute, 2 * Minute},
        {2*Minute + 30*Second, Minute, 3 * Minute},
        {2*Minute + 50*Second, Minute, 3 * Minute},
        {-Minute, 1, -Minute},
        {-2 * Minute, Minute, -2 * Minute},
        {-2*Minute - 10*Second, Minute, -2 * Minute},
        {-2*Minute - 30*Second, Minute, -3 * Minute},
        {-2*Minute - 50*Second, Minute, -3 * Minute},
        {8e18, 3e18, 9e18},
        {9e18, 5e18, 1<<63 - 1},
        {-8e18, 3e18, -9e18},
        {-9e18, 5e18, -1 << 63},
        {3<<61 - 1, 3 << 61, 3 << 61},
}

func TestDurationRound(t *testing.T) {
        for _, tt := range durationRoundTests {
                if got := tt.d.Round(tt.m); got != tt.want {
                        t.Errorf("Duration(%s).Round(%s) = %s; want: %s", tt.d, tt.m, got, tt.want)
                }
        }
}

var defaultLocTests = []struct {
        name string
        f    func(t1, t2 Time) bool
}{
        {"After", func(t1, t2 Time) bool { return t1.After(t2) == t2.After(t1) }},
        {"Before", func(t1, t2 Time) bool { return t1.Before(t2) == t2.Before(t1) }},
        {"Equal", func(t1, t2 Time) bool { return t1.Equal(t2) == t2.Equal(t1) }},

        {"IsZero", func(t1, t2 Time) bool { return t1.IsZero() == t2.IsZero() }},
        {"Date", func(t1, t2 Time) bool {
                a1, b1, c1 := t1.Date()
                a2, b2, c2 := t2.Date()
                return a1 == a2 && b1 == b2 && c1 == c2
        }},
        {"Year", func(t1, t2 Time) bool { return t1.Year() == t2.Year() }},
        {"Month", func(t1, t2 Time) bool { return t1.Month() == t2.Month() }},
        {"Day", func(t1, t2 Time) bool { return t1.Day() == t2.Day() }},
        {"Weekday", func(t1, t2 Time) bool { return t1.Weekday() == t2.Weekday() }},
        {"ISOWeek", func(t1, t2 Time) bool {
                a1, b1 := t1.ISOWeek()
                a2, b2 := t2.ISOWeek()
                return a1 == a2 && b1 == b2
        }},
        {"Clock", func(t1, t2 Time) bool {
                a1, b1, c1 := t1.Clock()
                a2, b2, c2 := t2.Clock()
                return a1 == a2 && b1 == b2 && c1 == c2
        }},
        {"Hour", func(t1, t2 Time) bool { return t1.Hour() == t2.Hour() }},
        {"Minute", func(t1, t2 Time) bool { return t1.Minute() == t2.Minute() }},
        {"Second", func(t1, t2 Time) bool { return t1.Second() == t2.Second() }},
        {"Nanosecond", func(t1, t2 Time) bool { return t1.Hour() == t2.Hour() }},
        {"YearDay", func(t1, t2 Time) bool { return t1.YearDay() == t2.YearDay() }},

        // Using Equal since Add don't modify loc using "==" will cause a fail
        {"Add", func(t1, t2 Time) bool { return t1.Add(Hour).Equal(t2.Add(Hour)) }},
        {"Sub", func(t1, t2 Time) bool { return t1.Sub(t2) == t2.Sub(t1) }},

        //Original caus for this test case bug 15852
        {"AddDate", func(t1, t2 Time) bool { return t1.AddDate(1991, 9, 3) == t2.AddDate(1991, 9, 3) }},

        {"UTC", func(t1, t2 Time) bool { return t1.UTC() == t2.UTC() }},
        {"Local", func(t1, t2 Time) bool { return t1.Local() == t2.Local() }},
        {"In", func(t1, t2 Time) bool { return t1.In(UTC) == t2.In(UTC) }},

        {"Local", func(t1, t2 Time) bool { return t1.Local() == t2.Local() }},
        {"Zone", func(t1, t2 Time) bool {
                a1, b1 := t1.Zone()
                a2, b2 := t2.Zone()
                return a1 == a2 && b1 == b2
        }},

        {"Unix", func(t1, t2 Time) bool { return t1.Unix() == t2.Unix() }},
        {"UnixNano", func(t1, t2 Time) bool { return t1.UnixNano() == t2.UnixNano() }},

        {"MarshalBinary", func(t1, t2 Time) bool {
                a1, b1 := t1.MarshalBinary()
                a2, b2 := t2.MarshalBinary()
                return bytes.Equal(a1, a2) && b1 == b2
        }},
        {"GobEncode", func(t1, t2 Time) bool {
                a1, b1 := t1.GobEncode()
                a2, b2 := t2.GobEncode()
                return bytes.Equal(a1, a2) && b1 == b2
        }},
        {"MarshalJSON", func(t1, t2 Time) bool {
                a1, b1 := t1.MarshalJSON()
                a2, b2 := t2.MarshalJSON()
                return bytes.Equal(a1, a2) && b1 == b2
        }},
        {"MarshalText", func(t1, t2 Time) bool {
                a1, b1 := t1.MarshalText()
                a2, b2 := t2.MarshalText()
                return bytes.Equal(a1, a2) && b1 == b2
        }},

        {"Truncate", func(t1, t2 Time) bool { return t1.Truncate(Hour).Equal(t2.Truncate(Hour)) }},
        {"Round", func(t1, t2 Time) bool { return t1.Round(Hour).Equal(t2.Round(Hour)) }},

        {"== Time{}", func(t1, t2 Time) bool { return (t1 == Time{}) == (t2 == Time{}) }},
}

func TestDefaultLoc(t *testing.T) {
        //This test verifyes that all Time's methods behaves identical if loc is set
        //as nil or UTC
        for _, tt := range defaultLocTests {
                t1 := Time{}
                t2 := Time{}.UTC()
                if !tt.f(t1, t2) {
                        t.Errorf("Time{} and Time{}.UTC() behave differently for %s", tt.name)
                }
        }
}

func BenchmarkNow(b *testing.B) {
        for i := 0; i < b.N; i++ {
                t = Now()
        }
}

func BenchmarkNowUnixNano(b *testing.B) {
        for i := 0; i < b.N; i++ {
                u = Now().UnixNano()
        }
}

func BenchmarkFormat(b *testing.B) {
        t := Unix(1265346057, 0)
        for i := 0; i < b.N; i++ {
                t.Format("Mon Jan  2 15:04:05 2006")
        }
}

func BenchmarkFormatNow(b *testing.B) {
        // Like BenchmarkFormat, but easier, because the time zone
        // lookup cache is optimized for the present.
        t := Now()
        for i := 0; i < b.N; i++ {
                t.Format("Mon Jan  2 15:04:05 2006")
        }
}

func BenchmarkMarshalJSON(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                t.MarshalJSON()
        }
}

func BenchmarkMarshalText(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                t.MarshalText()
        }
}

func BenchmarkParse(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Parse(ANSIC, "Mon Jan  2 15:04:05 2006")
        }
}

func BenchmarkParseDuration(b *testing.B) {
        for i := 0; i < b.N; i++ {
                ParseDuration("9007199254.740993ms")
                ParseDuration("9007199254740993ns")
        }
}

func BenchmarkHour(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                _ = t.Hour()
        }
}

func BenchmarkSecond(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                _ = t.Second()
        }
}

func BenchmarkYear(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                _ = t.Year()
        }
}

func BenchmarkDay(b *testing.B) {
        t := Now()
        for i := 0; i < b.N; i++ {
                _ = t.Day()
        }
}

func TestMarshalBinaryZeroTime(t *testing.T) {
        t0 := Time{}
        enc, err := t0.MarshalBinary()
        if err != nil {
                t.Fatal(err)
        }
        t1 := Now() // not zero
        if err := t1.UnmarshalBinary(enc); err != nil {
                t.Fatal(err)
        }
        if t1 != t0 {
                t.Errorf("t0=%#v\nt1=%#v\nwant identical structures", t0, t1)
        }
}

// Issue 17720: Zero value of time.Month fails to print
func TestZeroMonthString(t *testing.T) {
        if got, want := Month(0).String(), "%!Month(0)"; got != want {
                t.Errorf("zero month = %q; want %q", got, want)
        }
}

func TestReadFileLimit(t *testing.T) {
        const zero = "/dev/zero"
        if _, err := os.Stat(zero); err != nil {
                t.Skip("skipping test without a /dev/zero")
        }
        _, err := ReadFile(zero)
        if err == nil || !strings.Contains(err.Error(), "is too large") {
                t.Errorf("readFile(%q) error = %v; want error containing 'is too large'", zero, err)
        }
}