feat(M6): token ring data plane + engine — pending adds disappear on claim, topology written back for full cluster view (per authoritative design)

internal/cluster/ring_engine_test.go

@@ -0,0 +1,64 @@
+package cluster
+
+import (
+	"context"
+	"testing"
+)
+
+type fakeHandler struct {
+	load  Load
+	claim func(ctx context.Context, tk *Task) error
+}
+
+func (h *fakeHandler) RuntimeLoad() Load { return h.load }
+func (h *fakeHandler) Claim(ctx context.Context, tk *Task) error {
+	if h.claim != nil {
+		return h.claim(ctx, tk)
+	}
+	return nil
+}
+
+// sendNull is a no-op sender (single-node ring).
+func sendNull(ctx context.Context, next string, tk *Token) error { return nil }
+
+// TestSingleNodeCycle: leader starts ring, processes phases locally, and the
+// task gets claimed (lowest load = only node).
+func TestSingleNodeCycle(t *testing.T) {
+	eng := NewEngine("n1", "n1:7500", "u", "p", "0.71.0", []string{"0.71.0"},
+		&fakeHandler{load: Load{MemPct: 30, NetPct: 30}}, sendNull, "n1:7500", true)
+	eng.StartRing(context.Background())
+
+	// single node: token stays local; no successor so nothing travels.
+	if eng.State().Nodes[0].ID != "n1" {
+		t.Fatalf("nodes = %+v", eng.State().Nodes)
+	}
+}
+
+// TestTwoNodesPhaseCollect: leader n1 sends to n2; n1 collects both after n2
+// stamps; then phase flips and second round syncs.
+func TestTwoNodesCollectAndSync(t *testing.T) {
+	var n2loaded bool
+	eng2 := NewEngine("n2", "n2:7500", "u", "p", "0.71.0", nil,
+		&fakeHandler{load: Load{MemPct: 10, NetPct: 10}}, sendNull, "n2:7500", false)
+	// n2's state must include both (leader + itself) so AliveSuccessor works
+	eng2.state.UpsertNode(Node{ID: "n1", Addr: "n1:7500", Alive: true, IsLeader: true, Load: Load{MemPct: 50, NetPct: 50}})
+
+	// n1 sends a collect-phase token with itself in Passed.
+	eng2.state.UpsertNode(Node{ID: "n1", Addr: "n1:7500", Alive: true, IsLeader: true, Load: eng2.state.Nodes[0].Load})
+	tk := &Token{Cycle: 1, Phase: PhaseCollect, Passed: []string{"n1"},
+		State: *func() *State {
+			s := &State{}
+			s.UpsertNode(Node{ID: "n1", Addr: "n1:7500", Alive: true, IsLeader: true})
+			s.UpsertNode(Node{ID: "n2", Addr: "n2:7500", Alive: true})
+			return s
+		}()}
+	_ = n2loaded
+
+	out, err := eng2.OnToken(context.Background(), tk)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !contains(out.Passed, "n2") {
+		t.Fatalf("n2 not stamped in round1, passed=%v", out.Passed)
+	}
+}