GROOVY-11308: DefaultGroovyMethods#unique now returns null for empty …

…or 1 element input (minor refactor)
apache · Feb 14, 2024 · fac098f · fac098f
1 parent a43d5d4
commit fac098f
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/main/java/org/codehaus/groovy/runtime/DefaultGroovyMethods.java b/src/main/java/org/codehaus/groovy/runtime/DefaultGroovyMethods.java
@@ -14580,11 +14580,14 @@ public static <T> List<T> unique(List<T> self) {
      * @since 1.8.1
      */
     public static <T> Collection<T> unique(Collection<T> self, boolean mutate) {
+        Objects.requireNonNull(self);
+        if (!mutate && self.size() <= 1) {
+            return self;
+        }
         Collection<T> answer = uniqueItems(self);
         if (mutate) {
             self.clear();
             self.addAll(answer);
-
             return self;
         } else {
             return answer;