Added tests and readme

internal/replicate/replicator_test.go

@@ -0,0 +1,164 @@
+package replicate
+
+import (
+	"context"
+	"encoding/json"
+	"sync"
+	"testing"
+
+	"github.com/jasper/quptime/internal/config"
+	"github.com/jasper/quptime/internal/transport"
+)
+
+type fakeMaster struct {
+	master    string
+	isMaster  bool
+	hasQuorum bool
+}
+
+func (f *fakeMaster) Master() string  { return f.master }
+func (f *fakeMaster) IsMaster() bool  { return f.isMaster }
+func (f *fakeMaster) HasQuorum() bool { return f.hasQuorum }
+
+// stubClient records every Call without doing any actual I/O.
+type stubClient struct {
+	mu    sync.Mutex
+	calls []string
+}
+
+func (s *stubClient) Call(_ context.Context, _, _, method string, _, _ any) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.calls = append(s.calls, method)
+	return nil
+}
+
+func newReplicator(t *testing.T, isMaster, hasQuorum bool) (*Replicator, *config.ClusterConfig, *stubClient) {
+	t.Helper()
+	t.Setenv("QUPTIME_DIR", t.TempDir())
+	cluster := &config.ClusterConfig{}
+	fm := &fakeMaster{master: "self", isMaster: isMaster, hasQuorum: hasQuorum}
+	stub := &stubClient{}
+	r := New("self", cluster, stub, fm)
+	return r, cluster, stub
+}
+
+func TestApplyAddCheck(t *testing.T) {
+	r, cluster, _ := newReplicator(t, true, true)
+	payload, _ := json.Marshal(config.Check{ID: "c1", Name: "homepage", Type: config.CheckHTTP, Target: "https://example.com"})
+
+	ver, err := r.LocalMutate(context.Background(), transport.MutationAddCheck, json.RawMessage(payload))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ver != 1 {
+		t.Errorf("version=%d want 1", ver)
+	}
+	if len(cluster.Snapshot().Checks) != 1 {
+		t.Errorf("expected 1 check, got %d", len(cluster.Snapshot().Checks))
+	}
+}
+
+func TestApplyRemoveCheck(t *testing.T) {
+	r, cluster, _ := newReplicator(t, true, true)
+	_ = cluster.Mutate("self", func(c *config.ClusterConfig) error {
+		c.Checks = []config.Check{{ID: "c1", Name: "x"}, {ID: "c2", Name: "y"}}
+		return nil
+	})
+
+	target, _ := json.Marshal("x")
+	ver, err := r.LocalMutate(context.Background(), transport.MutationRemoveCheck, json.RawMessage(target))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ver < 2 {
+		t.Errorf("version did not advance: %d", ver)
+	}
+	cs := cluster.Snapshot().Checks
+	if len(cs) != 1 || cs[0].ID != "c2" {
+		t.Errorf("expected only c2 remaining, got %+v", cs)
+	}
+}
+
+func TestApplyAddAndRemoveAlertAndPeer(t *testing.T) {
+	r, cluster, _ := newReplicator(t, true, true)
+
+	alert, _ := json.Marshal(config.Alert{ID: "a1", Name: "notify", Type: config.AlertDiscord})
+	if _, err := r.LocalMutate(context.Background(), transport.MutationAddAlert, json.RawMessage(alert)); err != nil {
+		t.Fatal(err)
+	}
+
+	peer, _ := json.Marshal(config.PeerInfo{NodeID: "p1", Advertise: "10.0.0.1:9001", Fingerprint: "fp"})
+	if _, err := r.LocalMutate(context.Background(), transport.MutationAddPeer, json.RawMessage(peer)); err != nil {
+		t.Fatal(err)
+	}
+
+	snap := cluster.Snapshot()
+	if len(snap.Alerts) != 1 || len(snap.Peers) != 1 {
+		t.Fatalf("missing entries: %+v", snap)
+	}
+
+	target, _ := json.Marshal("notify")
+	if _, err := r.LocalMutate(context.Background(), transport.MutationRemoveAlert, json.RawMessage(target)); err != nil {
+		t.Fatal(err)
+	}
+	target, _ = json.Marshal("p1")
+	if _, err := r.LocalMutate(context.Background(), transport.MutationRemovePeer, json.RawMessage(target)); err != nil {
+		t.Fatal(err)
+	}
+
+	snap = cluster.Snapshot()
+	if len(snap.Alerts) != 0 || len(snap.Peers) != 0 {
+		t.Errorf("entries not removed: %+v", snap)
+	}
+}
+
+func TestMutateRequiresQuorum(t *testing.T) {
+	r, _, _ := newReplicator(t, true, false)
+	_, err := r.LocalMutate(context.Background(), transport.MutationAddCheck, json.RawMessage("{}"))
+	if err == nil {
+		t.Error("expected quorum-required error")
+	}
+}
+
+func TestHandleApplyClusterCfgGatesOnVersion(t *testing.T) {
+	r, cluster, _ := newReplicator(t, false, true)
+	// Push local version to 7 directly via Replace (Mutate would
+	// implicitly bump to 8 and confuse the test cases below).
+	if _, err := cluster.Replace(&config.ClusterConfig{Version: 7}); err != nil {
+		t.Fatal(err)
+	}
+
+	if resp := r.HandleApplyClusterCfg(transport.ApplyClusterCfgRequest{
+		Config: &config.ClusterConfig{Version: 6},
+	}); resp.Applied {
+		t.Error("older snapshot was applied")
+	}
+	if resp := r.HandleApplyClusterCfg(transport.ApplyClusterCfgRequest{
+		Config: &config.ClusterConfig{Version: 7},
+	}); resp.Applied {
+		t.Error("same-version snapshot was applied")
+	}
+
+	resp := r.HandleApplyClusterCfg(transport.ApplyClusterCfgRequest{
+		Config: &config.ClusterConfig{Version: 8, Checks: []config.Check{{ID: "n"}}},
+	})
+	if !resp.Applied {
+		t.Error("newer snapshot was rejected")
+	}
+	if cluster.Snapshot().Version != 8 {
+		t.Errorf("local version did not advance: %d", cluster.Snapshot().Version)
+	}
+}
+
+func TestHandleProposeMutationRejectsNonMaster(t *testing.T) {
+	r, _, _ := newReplicator(t, false, true)
+	resp := r.HandleProposeMutation(context.Background(), transport.ProposeMutationRequest{
+		FromNodeID: "follower",
+		Kind:       transport.MutationAddCheck,
+		Payload:    json.RawMessage(`{}`),
+	})
+	if resp.Error == "" {
+		t.Error("follower accepted a proposal")
+	}
+}