Return empty strings for batch and copyright (#31)

src/datasources/product-api.ts

@@ -104,6 +104,8 @@ export class ProductAPI extends BaseSQLDataSource {
     row.fields = this.getProductFields(row);
     row.designerId = row.designerid;
     row.orientation = this.getOrientation(row.fields);
+    row.copyright = row.copyright ?? '';
+    row.batch = row.batch ?? '';
     return row;
   }
 

src/schema.graphql

@@ -262,7 +262,7 @@ type ProductFields {
   photowallResolution: Int
   canvasResolution: Int
   wallpaperResolution: Int
-  copyright: String
+  copyright: String!
   proportionsWarning: String
   marginWidthMax: Int
   marginWidthMin: Int
@@ -272,7 +272,7 @@ type ProductFields {
   focusYpoint: Float
   focusXpoint2: Float
   focusYpoint2: Float
-  batch: String
+  batch: String!
   imageResolution: Int
   printFileWidth: Int
   printFileHeight: Int