refactor: split casino.go, dedup helpers, remove audit docs

1 files changed, 79 insertions, 0 deletions

diff --git a/internal/persistence/txn_containment_test.go b/internal/persistence/txn_containment_test.go
new file mode 100644
index 0000000..cfcd4c2
--- /dev/null
+++ b/internal/persistence/txn_containment_test.go
@@ -0,0 +1,79 @@
+package persistence
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestTxnMoveRejectsSamePath(t *testing.T) {
+	dir := t.TempDir()
+	txn := NewTransaction(filepath.Join(dir, ".journal"))
+	p := filepath.Join(dir, "a.yaml")
+	if err := txn.Move(p, p); err == nil {
+		t.Fatal("expected Move(path, path) to be rejected")
+	}
+}
+
+// A path that already received a Replace as a move destination carries an
+// after-image in its move-target record; a later Move would silently drop it.
+func TestTxnMoveRejectsReplacedMoveDestination(t *testing.T) {
+	dir := t.TempDir()
+	a := filepath.Join(dir, "a.yaml")
+	b := filepath.Join(dir, "b.yaml")
+	writeTestFile(t, a, "A")
+	writeTestFile(t, b, "B")
+	txn := NewTransaction(filepath.Join(dir, ".journal"))
+	if err := txn.Move(a, b); err != nil {
+		t.Fatal(err)
+	}
+	if err := txn.Replace(b, []byte("X"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if err := txn.Move(b, filepath.Join(dir, "c.yaml")); err == nil {
+		t.Fatal("expected Move over a replaced move destination to be rejected")
+	}
+}
+
+// A journal on disk is untrusted input: recovery must not replay a before-image
+// at a path outside the journal's data root.
+func TestRecoverRejectsEscapingOpPath(t *testing.T) {
+	dir := t.TempDir()
+	outside := t.TempDir()
+	journalDir := filepath.Join(dir, ".journal")
+	if err := os.MkdirAll(journalDir, 0700); err != nil {
+		t.Fatal(err)
+	}
+	escape := filepath.Join(outside, "secret.yaml")
+	body := `{"version":1,"ops":[{"path":"` + escape + `","kind":"delete","old_exists":false}]}`
+	evil := filepath.Join(journalDir, "txn-evil.json")
+	if err := os.WriteFile(evil, []byte(body), 0600); err != nil {
+		t.Fatal(err)
+	}
+	if err := Recover(journalDir); err == nil {
+		t.Fatal("expected Recover to reject an escaping op path")
+	}
+	// Fail loud and keep the journal rather than silently touching the path.
+	if _, err := os.Stat(evil); err != nil {
+		t.Fatalf("journal should be retained on rejection: %v", err)
+	}
+	if _, err := os.Stat(escape); !os.IsNotExist(err) {
+		t.Fatalf("escaping path must not be touched: %v", err)
+	}
+}
+
+func TestRecoverRejectsEscapingMoveTarget(t *testing.T) {
+	dir := t.TempDir()
+	outside := t.TempDir()
+	journalDir := filepath.Join(dir, ".journal")
+	if err := os.MkdirAll(journalDir, 0700); err != nil {
+		t.Fatal(err)
+	}
+	body := `{"version":1,"ops":[{"path":"` + filepath.Join(dir, "a.yaml") + `","kind":"move","move_to":"` + filepath.Join(outside, "b.yaml") + `"}]}`
+	if err := os.WriteFile(filepath.Join(journalDir, "txn-evil.json"), []byte(body), 0600); err != nil {
+		t.Fatal(err)
+	}
+	if err := Recover(journalDir); err == nil {
+		t.Fatal("expected Recover to reject an escaping move target")
+	}
+}