Create parent directory on replica restore (#793)

Author: mtlynch

replica.go

@@ -7,11 +7,14 @@ import (
 	"io"
 	"log/slog"
 	"os"
+	"path/filepath"
 	"sync"
 	"time"
 
 	"filippo.io/age"
 	"github.com/superfly/ltx"
+
+	"github.com/benbjohnson/litestream/internal"
 )
 
 // Default replica settings.
@@ -446,6 +449,15 @@ func (r *Replica) Restore(ctx context.Context, opt RestoreOptions) (err error) {
 		return fmt.Errorf("no matching backup files available")
 	}
 
+	// Create parent directory if it doesn't exist.
+	var dirInfo os.FileInfo
+	if db := r.DB(); db != nil {
+		dirInfo = db.dirInfo
+	}
+	if err := internal.MkdirAll(filepath.Dir(opt.OutputPath), dirInfo); err != nil {
+		return fmt.Errorf("create parent directory: %w", err)
+	}
+
 	// Output to temp file & atomically rename.
 	tmpOutputPath := opt.OutputPath + ".tmp"
 	r.Logger().Debug("compacting into database", "path", tmpOutputPath, "n", len(rdrs))

replica_test.go

@@ -217,14 +217,16 @@ func TestReplica_RestoreAndReplicateAfterDataLoss(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Restore again
+	// Restore to a path with non-existent parent directory to verify it gets created
+	restoredPath := dbDir + "/restored/db.sqlite"
+	restoreOpt.OutputPath = restoredPath
 	if err := db2.Replica.Restore(ctx, restoreOpt); err != nil {
 		t.Fatal(err)
 	}
-	t.Log("Step 4 complete: Second restore from backup")
+	t.Log("Step 4 complete: Second restore from backup to path with non-existent parent")
 
 	// Step 5: Verify the new data (value=2) exists in restored database
-	sqldb3 := testingutil.MustOpenSQLDB(t, dbPath)
+	sqldb3 := testingutil.MustOpenSQLDB(t, restoredPath)
 	defer sqldb3.Close()
 
 	var count int