tweak

Author: Rich-Harris

src/stringify.js

@@ -81,8 +81,8 @@ export function stringify(value, reducers) {
 					break;
 
 				case 'Date':
-					const isValidDate = !isNaN(thing.getDate())
-					str = `["Date","${isValidDate ? thing.toISOString() : ''}"]`;
+					const valid = !isNaN(thing.getDate());
+					str = `["Date","${valid ? thing.toISOString() : ''}"]`;
 					break;
 
 				case 'RegExp':