Documentation
¶
Overview ¶
Package testclock provides a clock.Clock for tests that advances only when told to.
A TestClock starts at a fixed time and never moves on its own. Timers started with After fire when the test calls Advance or Set and moves the clock past their due time. BlockUntil waits until the code under test has started a given number of timers, so a test can advance the clock exactly when the code is waiting, without sleeping.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type TestClock ¶
type TestClock struct {
// contains filtered or unexported fields
}
TestClock is a manually driven clock.Clock. It is safe for concurrent use.
func New ¶
New creates a test clock that starts at the given time.
Parameters:
- start: The initial time of the clock
Returns:
- *TestClock: A clock that only moves with Advance and Set
Example ¶
ExampleNew creates a test clock at a fixed time.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
fmt.Println(c.Now().Format(time.RFC3339))
}
Output: 2024-01-01T00:00:00Z
func (*TestClock) Advance ¶
Advance moves the clock forward by d and fires every timer that is due, in the order of their due times. Timers with the same due time fire in the order they were started.
Parameters:
- d: The duration to advance the clock by
Example ¶
ExampleTestClock_Advance fires the timers that become due.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
short, _ := c.After(time.Second)
long, _ := c.After(time.Hour)
c.Advance(time.Minute)
fmt.Println((<-short).Sub(start))
c.Advance(time.Hour)
fmt.Println((<-long).Sub(start))
}
Output: 1s 1h0m0s
func (*TestClock) After ¶
After starts a timer that fires once the clock has advanced by d.
A timer with a duration of zero or less fires immediately. The returned stop function removes a pending timer and reports whether it was still pending.
Example ¶
ExampleTestClock_After starts a timer that fires when the clock is advanced.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
ch, _ := c.After(time.Minute)
c.Advance(time.Minute)
fmt.Println((<-ch).Format(time.Kitchen))
}
Output: 12:01AM
func (*TestClock) BlockUntil ¶
BlockUntil waits until at least n timers are pending, that is started and neither fired nor stopped.
Parameters:
- n: The number of pending timers to wait for
Example ¶
ExampleTestClock_BlockUntil waits until another goroutine is sleeping before advancing.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
done := make(chan time.Time)
go func() {
ch, stop := c.After(time.Hour)
defer stop()
done <- <-ch
}()
c.BlockUntil(1)
c.Advance(time.Hour)
fmt.Println((<-done).Format(time.Kitchen))
}
Output: 1:00AM
func (*TestClock) Now ¶
Now returns the current time of the clock.
Example ¶
ExampleTestClock_Now shows that the clock does not move on its own.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
fmt.Println(c.Now().Equal(c.Now()))
}
Output: true
func (*TestClock) Set ¶
Set moves the clock to t and fires every timer that is due, in the order of their due times. Moving the clock backwards fires no timers.
Parameters:
- t: The new time of the clock
Example ¶
ExampleTestClock_Set moves the clock to an absolute time.
package main
import (
"fmt"
"time"
"github.com/IBM/fp-go/v2/clock/testclock"
)
var start = time.Date(2024, 1, 1, 0, 0, 0, 0, time.UTC)
func main() {
c := testclock.New(start)
c.Set(start.AddDate(0, 0, 1))
fmt.Println(c.Now().Format(time.DateOnly))
}
Output: 2024-01-02
Source Files