在 golang 中， Time.Format() 从小数部分删除尾随零

Question

如何防止 go 的 Time.Format() 从小数部分中删除尾随零？我有以下单元测试失败。

package main

import (
    "testing"
    "time"
)

func TestTimeFormatting(t *testing.T) {
    timestamp := time.Date(2017, 1,2, 3, 4, 5, 600000*1000, time.UTC)
    timestamp_string := timestamp.Format("2006-01-02T15:04:05.999-07:00")
    expected := "2017-01-02T03:04:05.600+00:00"

    if expected != timestamp_string {
        t.Errorf("Invalid timestamp formating, expected %v, got %v", expected, timestamp_string)
    }
}

输出：

$ go test
--- FAIL: TestTimeFormatting (0.00s)
    main_test.go:14: Invalid timestamp formating, expected 2017-01-02T03:04:05.600+00:00, got 2017-01-02T03:04:05.6+00:00
FAIL
exit status 1
FAIL    _/home/sasa/Bugs/go-formatter   0.001s

知道如何解决这个问题吗？

Answer 1

啊，文档中有没有。如果您想保留零，应该使用 000 而不是 999。

package main

import (
    "testing"
    "time"
)

func TestTimeFormatting(t *testing.T) {
    timestamp := time.Date(2017, 1,2, 3, 4, 5, 600000*1000, time.UTC)
    timestamp_string := timestamp.Format("2006-01-02T15:04:05.000-07:00")
    expected := "2017-01-02T03:04:05.600+00:00"

    if expected != timestamp_string {
        t.Errorf("Invalid timestamp formating, expected %v, got %v", expected, timestamp_string)
    }
}