Merged in feature/stabilisetimeNow (pull request #125)

inject time.now for tesability

* inject

internal/serviceconfig/build/build.go

@@ -25,16 +25,16 @@ var startupTime time.Time
 var startupTimeOnce sync.Once
 
 func GetVersionTimestamp() time.Time {
-	startupTimeOnce.Do(getStartTime(&startupTime, debug.ReadBuildInfo))
+	startupTimeOnce.Do(getStartTime(&startupTime, debug.ReadBuildInfo, time.Now))
 
 	return startupTime
 }
 
-func getStartTime(startupTime *time.Time, readBuildInfo func() (info *debug.BuildInfo, ok bool)) func() {
+func getStartTime(startupTime *time.Time, readBuildInfo func() (info *debug.BuildInfo, ok bool), clock func() time.Time) func() {
 	return func() {
 		info, ok := readBuildInfo()
 		if !ok {
-			*startupTime = time.Now().UTC()
+			*startupTime = clock()
 			return
 		}
 
@@ -52,7 +52,7 @@ func getStartTime(startupTime *time.Time, readBuildInfo func() (info *debug.Buil
 		}
 
 		// Return current time if no build time found
-		*startupTime = time.Now().UTC()
+		*startupTime = clock()
 	}
 }
 

internal/serviceconfig/build/build_test.go

@@ -51,27 +51,30 @@ func TestGetVersionTimestamp(t *testing.T) {
 }
 
 func TestGetStartTime(t *testing.T) {
+	injectedTime := time.Now().UTC()
+	injectTime := func() time.Time {
+		return injectedTime
+	}
+	vcsTime := time.Now().UTC()
 	t.Run("vcs time", func(t *testing.T) {
 		var tt time.Time
-		expectedTime := time.Now().UTC()
 		f := getStartTime(&tt, func() (info *debug.BuildInfo, ok bool) {
 			return &debug.BuildInfo{
 				Settings: []debug.BuildSetting{
 					{
 						Key:   "vcs.time",
-						Value: expectedTime.Format(time.RFC3339),
+						Value: vcsTime.Format(time.RFC3339),
 					},
 				},
 			}, true
-		})
+		}, injectTime)
 		assert.NotNil(t, f)
 		f()
-		assert.Equal(t, expectedTime.Truncate(time.Second), tt)
+		assert.Equal(t, vcsTime.Truncate(time.Second), tt)
 	})
 	t.Run("vcs time - invalid format", func(t *testing.T) {
 		var tt time.Time
 		// to make the test less likely to fail due to non deterministic temporal issues.
-		expectedTime := time.Now().UTC().Add(-time.Millisecond)
 		f := getStartTime(&tt, func() (info *debug.BuildInfo, ok bool) {
 			return &debug.BuildInfo{
 				Settings: []debug.BuildSetting{
@@ -81,10 +84,27 @@ func TestGetStartTime(t *testing.T) {
 					},
 				},
 			}, true
-		})
+		}, injectTime)
 		assert.NotNil(t, f)
 		f()
-		assert.True(t, expectedTime.Before(tt))
+		assert.Equal(t, injectedTime, tt)
+	})
+	t.Run("vcs time - not available", func(t *testing.T) {
+		var tt time.Time
+		// to make the test less likely to fail due to non deterministic temporal issues.
+		f := getStartTime(&tt, func() (info *debug.BuildInfo, ok bool) {
+			return &debug.BuildInfo{
+				Settings: []debug.BuildSetting{
+					{
+						Key:   "vcs.time",
+						Value: "invalid",
+					},
+				},
+			}, true
+		}, injectTime)
+		assert.NotNil(t, f)
+		f()
+		assert.Equal(t, injectedTime, tt)
 	})
 }