feat: 기본 unit test 등록

hwe/ts/util/RandUtil.ts

@@ -37,6 +37,9 @@ export class RandUtil {
 
     public shuffle<T>(srcArray: T[]): T[] {
         const cnt = srcArray.length;
+        if(cnt === 0){
+            return [];
+        }
         if (cnt > this.rng.getMaxInt()) {
             throw 'Invalid random int range';
         }
@@ -54,6 +57,9 @@ export class RandUtil {
 
     public choice<T>(items: T[] | Record<string | number, T> | Set<T>): T {
         if (items instanceof Array) {
+            if(items.length === 0){
+                throw new Error('Empty items');
+            }
             const idx = this.rng.nextInt(items.length - 1);
             return items[idx];
         }
@@ -66,6 +72,9 @@ export class RandUtil {
     }
 
     public choiceUsingWeight(items: Record<string | number, number>): string | number {
+        if(Object.keys(items).length === 0){
+            throw new Error('Empty items');
+        }
         let sum = 0;
         for (const value of Object.values(items)) {
             if (value <= 0) {
@@ -94,6 +103,9 @@ export class RandUtil {
     }
 
     public choiceUsingWeightPair<T>(items: [T, number][]): T {
+        if(items.length === 0){
+            throw new Error('Empty items');
+        }
         let sum = 0;
         for (const [, value] of items) {
             if (value <= 0) {