1 files changed, 105 insertions, 0 deletions
diff --git a/internal/checkpoint/checkpoint_test.go b/internal/checkpoint/checkpoint_test.go
new file mode 100644
index 0000000..9ca9b2a
--- /dev/null
+++ b/internal/checkpoint/checkpoint_test.go
@@ -0,0 +1,105 @@
+package checkpoint
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/base64"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/Fuwn/plutia/internal/storage"
+	"github.com/Fuwn/plutia/internal/types"
+)
+
+func TestBuildAndStoreCheckpoint(t *testing.T) {
+	tmp := t.TempDir()
+	store, err := storage.OpenPebble(tmp)
+	if err != nil {
+		t.Fatalf("open pebble: %v", err)
+	}
+	defer store.Close()
+
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("generate key: %v", err)
+	}
+	keyPath := filepath.Join(tmp, "mirror.key")
+	if err := os.WriteFile(keyPath, []byte(base64.RawURLEncoding.EncodeToString(priv)), 0o600); err != nil {
+		t.Fatalf("write key: %v", err)
+	}
+
+	mgr := NewManager(store, tmp, keyPath)
+	states := []types.StateV1{
+		{Version: 1, DID: "did:plc:a", ChainTipHash: "tip-a"},
+		{Version: 1, DID: "did:plc:b", ChainTipHash: "tip-b"},
+	}
+	cp, err := mgr.BuildAndStore(42, states, []string{"abc", "def"})
+	if err != nil {
+		t.Fatalf("build checkpoint: %v", err)
+	}
+	if cp.Signature == "" || cp.CheckpointHash == "" {
+		t.Fatalf("expected signed checkpoint")
+	}
+	payload, err := marshalCheckpointPayload(cp)
+	if err != nil {
+		t.Fatalf("marshal payload: %v", err)
+	}
+	rawSig, err := base64.RawURLEncoding.DecodeString(cp.Signature)
+	if err != nil {
+		t.Fatalf("decode signature: %v", err)
+	}
+	if !ed25519.Verify(pub, payload, rawSig) {
+		t.Fatalf("signature verification failed")
+	}
+
+	stored, ok, err := store.GetCheckpoint(cp.Sequence)
+	if err != nil || !ok {
+		t.Fatalf("stored checkpoint missing: ok=%v err=%v", ok, err)
+	}
+	if stored.CheckpointHash != cp.CheckpointHash {
+		t.Fatalf("checkpoint hash mismatch")
+	}
+}
+
+func TestCheckpointRootStability(t *testing.T) {
+	tmp := t.TempDir()
+	store, err := storage.OpenPebble(tmp)
+	if err != nil {
+		t.Fatalf("open pebble: %v", err)
+	}
+	defer store.Close()
+
+	if err := store.PutState(types.StateV1{Version: 1, DID: "did:plc:b", ChainTipHash: "tip-b"}); err != nil {
+		t.Fatalf("put state b: %v", err)
+	}
+	if err := store.PutState(types.StateV1{Version: 1, DID: "did:plc:a", ChainTipHash: "tip-a"}); err != nil {
+		t.Fatalf("put state a: %v", err)
+	}
+
+	_, priv, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("generate key: %v", err)
+	}
+	keyPath := filepath.Join(tmp, "mirror.key")
+	if err := os.WriteFile(keyPath, []byte(base64.RawURLEncoding.EncodeToString(priv)), 0o600); err != nil {
+		t.Fatalf("write key: %v", err)
+	}
+
+	mgr := NewManager(store, tmp, keyPath)
+	cp1, err := mgr.BuildAndStoreFromStore(100, []string{"abc"})
+	if err != nil {
+		t.Fatalf("build checkpoint 1: %v", err)
+	}
+	cp2, err := mgr.BuildAndStoreFromStore(200, []string{"abc"})
+	if err != nil {
+		t.Fatalf("build checkpoint 2: %v", err)
+	}
+
+	if cp1.DIDMerkleRoot != cp2.DIDMerkleRoot {
+		t.Fatalf("did root changed for identical state: %s vs %s", cp1.DIDMerkleRoot, cp2.DIDMerkleRoot)
+	}
+	if cp1.BlockMerkleRoot != cp2.BlockMerkleRoot {
+		t.Fatalf("block root changed for identical block set: %s vs %s", cp1.BlockMerkleRoot, cp2.BlockMerkleRoot)
+	}
+}