adding comments to special generation codes

vueuse · Jul 10, 2022 · fe25afe · fe25afe
1 parent 8d6f84e
commit fe25afe
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/packages/math/useSum/index.ts b/packages/math/useSum/index.ts
@@ -26,6 +26,8 @@ export function useSum<T>(
 
     const reduceCallback = (sum: any, value: any, index: number) => adder(resolveUnref(sum), resolveUnref(value), index)
 
+    // Depending on the behavior of reduce, undefined is also a valid initialization value,
+    // and this code will distinguish the behavior between them.
     return args.length
       ? reduce(reduceCallback, args[0])
       : reduce(reduceCallback)