Fix #1678 by speeding up IsMergeable retries when testing. (#1684)

before:
ok      k8s.io/contrib/mungegithub/mungers      65.728s
after:
ok      k8s.io/contrib/mungegithub/mungers      3.886s

mungegithub/github/github.go

@@ -163,8 +163,8 @@ type Config struct {
 	// If true, don't make any mutating API calls
 	DryRun bool
 
-	// Defaults to 30 seconds.
-	PendingWaitTime *time.Duration
+	// Base sleep time for retry loops. Defaults to 1 second.
+	BaseWaitTime time.Duration
 
 	// When we clear analytics we store the last values here
 	lastAnalytics analytics
@@ -1183,8 +1183,8 @@ func (obj *MungeObject) doWaitStatus(pending bool, requiredContexts []string, c
 		}
 		sleepTime := 30 * time.Second
 		// If the time was explicitly set, use that instead
-		if config.PendingWaitTime != nil {
-			sleepTime = *config.PendingWaitTime
+		if config.BaseWaitTime != 0 {
+			sleepTime = 30 * config.BaseWaitTime
 		}
 		if pending {
 			glog.V(4).Infof("PR# %d is not pending, waiting for %f seconds", *obj.Issue.Number, sleepTime.Seconds())
@@ -1730,7 +1730,11 @@ func (obj *MungeObject) IsMergeable() (bool, error) {
 		// Sleep for 2-32 seconds on successive attempts.
 		// Worst case, we'll wait for up to a minute for GitHub
 		// to compute it before bailing out.
-		time.Sleep((1 << uint(try)) * time.Second)
+		baseDelay := time.Second
+		if obj.config.BaseWaitTime != 0 { // Allow shorter delays in tests.
+			baseDelay = obj.config.BaseWaitTime
+		}
+		time.Sleep((1 << uint(try)) * baseDelay)
 		err := obj.Refresh()
 		if err != nil {
 			glog.Errorf("Unable to refresh PR# %d: %v", prNum, err)

mungegithub/mungers/submit-queue_test.go

@@ -896,9 +896,8 @@ func TestSubmitQueue(t *testing.T) {
 		config.Org = "o"
 		config.Project = "r"
 		config.SetClient(client)
-		// Don't wait so long for it to go pending or back
-		d := 250 * time.Millisecond
-		config.PendingWaitTime = &d
+		// Don't wait so long for retries (pending, mergeability)
+		config.BaseWaitTime = time.Millisecond
 
 		stateSet := ""
 		wasMerged := false