61175ef091
- over the course of a project history every maintainer needs to update
its dependency packages, the problem essentially with godep is manipulating
GOPATH - this manipulation leads to static objects created at different locations
which end up conflicting with the overall functionality of golang.
This also leads to broken builds. There is no easier way out of this other than
asking developers to do 'godep restore' all the time. Which perhaps as a practice
doesn't sound like a clean solution. On the other hand 'godep restore' has its own
set of problems.
- govendor is a right tool but a stop gap tool until we wait for golangs official
1.5 version which fixes this vendoring issue once and for all.
- govendor provides consistency in terms of how import paths should be handled unlike
manipulation GOPATH.
This has advantages
- no more compiled objects being referenced in GOPATH and build time GOPATH
manging which leads to conflicts.
- proper import paths referencing the exact package a project is dependent on.
govendor is simple and provides the minimal necessary tooling to achieve this.
For now this is the right solution.
clock 
Clock is a small library for mocking time in Go. It provides an interface
around the standard library's time package so that the application
can use the realtime clock while tests can use the mock clock.
Usage
Realtime Clock
Your application can maintain a Clock variable that will allow realtime and
mock clocks to be interchangable. For example, if you had an Application type:
import "github.com/benbjohnson/clock"
type Application struct {
Clock clock.Clock
}
You could initialize it to use the realtime clock like this:
var app Application
app.Clock = clock.New()
...
Then all timers and time-related functionality should be performed from the
Clock variable.
Mocking time
In your tests, you will want to use a Mock clock:
import (
"testing"
"github.com/benbjohnson/clock"
)
func TestApplication_DoSomething(t *testing.T) {
mock := clock.NewMock()
app := Application{Clock: mock}
...
}
Now that you've initialized your application to use the mock clock, you can adjust the time programmatically. The mock clock always starts from the Unix epoch (midnight, Jan 1, 1970 UTC).
Controlling time
The mock clock provides the same functions that the standard library's time
package provides. For example, to find the current time, you use the Now()
function:
mock := clock.NewMock()
// Find the current time.
mock.Now().UTC() // 1970-01-01 00:00:00 +0000 UTC
// Move the clock forward.
mock.Add(2 * time.Hour)
// Check the time again. It's 2 hours later!
mock.Now().UTC() // 1970-01-01 02:00:00 +0000 UTC
Timers and Tickers are also controlled by this same mock clock. They will only execute when the clock is moved forward:
mock := clock.NewMock()
count := 0
// Kick off a timer to increment every 1 mock second.
go func() {
ticker := clock.Ticker(1 * time.Second)
for {
<-ticker.C
count++
}
}()
runtime.Gosched()
// Move the clock forward 10 second.
mock.Add(10 * time.Second)
// This prints 10.
fmt.Println(count)