fixup! feat(cosmos): wire swingset RestoreExtension

Refactor payloadReader loop

golang/cosmos/x/swingset/keeper/snapshotter.go

@@ -315,23 +315,27 @@ func (snapshotter *SwingsetSnapshotter) RestoreExtension(height uint64, format u
 
 	artifactNameSanitizer := regexp.MustCompile(`[^-_.a-zA-Z0-9]`)
 
-	i := 0
+	writeExportFile := func(filename string, data []byte) error {
+		return os.WriteFile(filepath.Join(exportDir, filename), data, ExportedFilesMode)
+	}
+
 	for {
 		payloadBytes, err := payloadReader()
 		if err == io.EOF {
 			break
 		} else if err != nil {
 			return err
 		}
+
 		payload := types.ExtensionSnapshotterArtifactPayload{}
-		err = payload.Unmarshal(payloadBytes)
-		if err != nil {
+		if err = payload.Unmarshal(payloadBytes); err != nil {
 			return err
 		}
 
 		filename := artifactNameSanitizer.ReplaceAllString(filepath.Base(payload.Name), "-")
-		filename = fmt.Sprintf("%d-%s", i, filename)
-		i += 1
+		filename = fmt.Sprintf("%d-%s", len(manifest.Artifacts), filename)
+		manifest.Artifacts = append(manifest.Artifacts, [2]string{payload.Name, filename})
+		err = writeExportFile(filename, payload.Data)
 
 		if payload.Name == UntrustedExportDataArtifactName {
 			if len(swingStoreEntries) == 0 {
@@ -346,14 +350,9 @@ func (snapshotter *SwingsetSnapshotter) RestoreExtension(height uint64, format u
 			}
 		}
 
-		err = os.WriteFile(filepath.Join(exportDir, filename), payload.Data, ExportedFilesMode)
 		if err != nil {
 			return err
 		}
-
-		if payload.Name != UntrustedExportDataArtifactName {
-			manifest.Artifacts = append(manifest.Artifacts, [2]string{payload.Name, filename})
-		}
 	}
 
 	err = exportDataFile.Sync()
@@ -366,7 +365,7 @@ func (snapshotter *SwingsetSnapshotter) RestoreExtension(height uint64, format u
 	if err != nil {
 		return err
 	}
-	err = os.WriteFile(filepath.Join(exportDir, ExportManifestFilename), manifestBytes, ExportedFilesMode)
+	err = writeExportFile(ExportManifestFilename, manifestBytes)
 	if err != nil {
 		return err
 	}