Add context-aware "time" library wrapper.

go/src/infra/gae/libs/wrapper/dummy_test.go

 // Copyright 2015 The Chromium 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 wrapper
 
 import (
         "math/rand"
         "testing"
         "time"
 
         "golang.org/x/net/context"
 
         "appengine/memcache"
 
         . "github.com/smartystreets/goconvey/convey"
+        "infra/libs/clock"
+        "infra/libs/clock/testclock"
 )
 
 func TestContextAccess(t *testing.T) {
         Convey("Context Access", t, func() {
                 c := context.Background()
 
+                now := time.Date(2015, 1, 1, 0, 0, 0, 0, time.UTC)
+                tc := testclock.New(now)
+                c = clock.SetClock(c, tc)

[iannucci, 2015/06/03 17:37:19]

wdyt about 

  c = testclock.UseTime(c, time.Date(...))  

(which calls clock.SetClock internally)?

[dnj, 2015/06/03 18:21:26]

You need a reference to the test clock in order to poke it. We could do:
ctx, clock := testclock.UseTime(time.Date(...))

+
                 Convey("blank", func() {
                         So(GetDS(c), ShouldBeNil)
                         So(GetMC(c), ShouldBeNil)
                         So(GetTQ(c), ShouldBeNil)
                         So(GetGI(c), ShouldBeNil)
-
-                        now := time.Now()
-                        So(GetTimeNow(c), ShouldHappenOnOrAfter, now)
                 })
 
                 Convey("DS", func() {
                         c = SetDS(c, DummyDS())
                         So(GetDS(c), ShouldNotBeNil)
                         So(func() { GetDS(c).Kind(nil) }, ShouldPanic)
                 })
 
                 Convey("MC", func() {
                         c = SetMC(c, DummyMC())
@@ skipping 11 matching lines @@
                         c = SetGI(c, DummyGI())
                         So(GetGI(c), ShouldNotBeNil)
                         So(func() { GetGI(c).Datacenter() }, ShouldPanic)
                 })
 
                 Convey("QY", func() {
                         q := DummyQY()
                         So(func() { q.Distinct() }, ShouldPanic)
                 })
 
-                Convey("TimeNow", func() {
-                        thing := time.Date(2000, time.August, 20, 0, 0, 0, 0, time.UTC)
-                        c = SetTimeNow(c, &thing)
-                        So(GetTimeNow(c), ShouldResemble, thing)
+                Convey("MathRand", func() {
+                        r := rand.New(rand.NewSource(now.UnixNano()))
+                        i := r.Int()
 
-                        Convey("MathRand", func() {
-                                r := rand.New(rand.NewSource(thing.UnixNano()))
-                                i := r.Int()
+                        // when it's unset it picks the current time every time
+                        So(GetMathRand(c).Int(), ShouldEqual, i)
+                        So(GetMathRand(c).Int(), ShouldEqual, i)
 
-                                // when it's unset it picks TimeNow every time
-                                So(GetMathRand(c).Int(), ShouldEqual, i)
-                                So(GetMathRand(c).Int(), ShouldEqual, i)
-
-                                // But we could set it to something concrete to have it persist.
-                                c = SetMathRand(c, rand.New(rand.NewSource(thing.UnixNano())))
-                                r = rand.New(rand.NewSource(thing.UnixNano()))
-                                So(GetMathRand(c).Int(), ShouldEqual, r.Int())
-                                So(GetMathRand(c).Int(), ShouldEqual, r.Int())
-                        })
-
-                        c = SetTimeNow(c, nil)
-                        now := time.Now()
-                        So(GetTimeNow(c), ShouldHappenOnOrAfter, now)
+                        // But we could set it to something concrete to have it persist.
+                        c = SetMathRand(c, rand.New(rand.NewSource(now.UnixNano())))
+                        r = rand.New(rand.NewSource(now.UnixNano()))
+                        So(GetMathRand(c).Int(), ShouldEqual, r.Int())
+                        So(GetMathRand(c).Int(), ShouldEqual, r.Int())
                 })
-
         })
 }