peer metadata store test improved

problem has come up that the package we are using does not expose the iterator of the underlying kv store so a wrapper will be made to embed it and add this functionality to the back end exposed.

pkg/engine/peerstore_test.go

@@ -95,7 +95,9 @@ func pauza() {
 func TestEngine_PeerStoreDiscovery(t *testing.T) {
 	// This test doesn't have a concrete failure mode, as inevitably the nodes
 	// that start in the first half of the set, and the nodes in the second
-	// half, the latter may miss the former's advertisements.
+	// half, the latter may miss the former's advertisements. If the functions
+	// are broken this will fail however, as this is the conditions that trigger
+	// a failure.
 	//
 	// It is more for demonstration to see that the gossip is indeed propagating
 	// in the first round as nodes start up, and more comprehensive tests by
@@ -104,7 +106,7 @@ func TestEngine_PeerStoreDiscovery(t *testing.T) {
 	if indra.CI == "false" {
 		log2.SetLogLevel(log2.Trace)
 	}
-	const nTotal = 20
+	const nTotal = 10
 	var e error
 	var engines []*Engine
 	var cleanup func()
@@ -112,8 +114,20 @@ func TestEngine_PeerStoreDiscovery(t *testing.T) {
 	if engines, cleanup, e = CreateAndStartMockEngines(nTotal, ctx); fails(e) {
 		t.FailNow()
 	}
-	_ = engines
-	time.Sleep(time.Second * 8)
+	time.Sleep(time.Second * 3)
+	// Send them all again after a bit to make sure everyone gets them.
+	for i := range engines {
+		if e = engines[i].SendAds(); fails(e) {
+			t.FailNow()
+		}
+	}
+	time.Sleep(time.Second * 3)
+	for i := range engines {
+		_ = i
+		// check that all peers now have nTotal-1 distinct peer ads (of all 4
+		// types)
+
+	}
 	cleanup()
 	pauza()
 }