fix: make Codex hooks transactional

cmd/elydora/plugins/transaction_recovery_test.go

@@ -0,0 +1,106 @@
+package plugins
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func transactionTestChanges(t *testing.T) (string, string, []*fileChange) {
+	t.Helper()
+	directory := t.TempDir()
+	firstPath := filepath.Join(directory, "first.json")
+	secondPath := filepath.Join(directory, "second.json")
+	for _, item := range []struct {
+		path    string
+		content string
+	}{
+		{firstPath, "first-original"},
+		{secondPath, "second-original"},
+	} {
+		if err := os.WriteFile(item.path, []byte(item.content), 0600); err != nil {
+			t.Fatalf("write transaction fixture: %v", err)
+		}
+	}
+	first, err := prepareFileChange(firstPath, "first test file", []byte("first-next"), 0600)
+	if err != nil {
+		t.Fatalf("prepare first transaction change: %v", err)
+	}
+	second, err := prepareFileChange(secondPath, "second test file", []byte("second-next"), 0600)
+	if err != nil {
+		t.Fatalf("prepare second transaction change: %v", err)
+	}
+	return firstPath, secondPath, []*fileChange{first, second}
+}
+
+func requirePreservedRollback(t *testing.T, directory string) {
+	t.Helper()
+	entries, err := os.ReadDir(directory)
+	if err != nil {
+		t.Fatalf("read transaction directory: %v", err)
+	}
+	var rollbackPath string
+	for _, entry := range entries {
+		if strings.HasSuffix(entry.Name(), ".rollback") {
+			if rollbackPath != "" {
+				t.Fatal("multiple rollback files remain")
+			}
+			rollbackPath = filepath.Join(directory, entry.Name())
+		}
+	}
+	if rollbackPath == "" {
+		t.Fatal("original rollback file was removed")
+	}
+	content, err := os.ReadFile(rollbackPath)
+	if err != nil {
+		t.Fatalf("read preserved rollback file: %v", err)
+	}
+	if string(content) != "first-original" {
+		t.Fatalf("preserved rollback content = %q", content)
+	}
+}
+
+func TestTransactionPreservesBackupAfterConcurrentCommittedChange(t *testing.T) {
+	firstPath, secondPath, changes := transactionTestChanges(t)
+	rename := func(source, destination string) error {
+		if destination == secondPath && strings.HasSuffix(source, ".tmp") {
+			if err := os.Remove(firstPath); err != nil {
+				return err
+			}
+			if err := os.WriteFile(firstPath, []byte("external"), 0600); err != nil {
+				return err
+			}
+			return errors.New("simulated second commit failure")
+		}
+		return os.Rename(source, destination)
+	}
+	err := writeChanges(changes, "Test transaction", rename)
+	if err == nil || !strings.Contains(err.Error(), "original content preserved at") {
+		t.Fatalf("transaction error = %v", err)
+	}
+	current, readErr := os.ReadFile(firstPath)
+	if readErr != nil || string(current) != "external" {
+		t.Fatalf("external content = %q, %v", current, readErr)
+	}
+	requirePreservedRollback(t, filepath.Dir(firstPath))
+}
+
+func TestTransactionPreservesBackupAfterRollbackRenameFailure(t *testing.T) {
+	firstPath, secondPath, changes := transactionTestChanges(t)
+	rename := func(source, destination string) error {
+		if destination == secondPath && strings.HasSuffix(source, ".tmp") {
+			return errors.New("simulated second commit failure")
+		}
+		if destination == firstPath && strings.HasSuffix(source, ".rollback") {
+			return errors.New("simulated rollback failure")
+		}
+		return os.Rename(source, destination)
+	}
+	err := writeChanges(changes, "Test transaction", rename)
+	if err == nil || !strings.Contains(err.Error(), "original content preserved at") {
+		t.Fatalf("transaction error = %v", err)
+	}
+	requirePreservedRollback(t, filepath.Dir(firstPath))
+}