feat: arrayUnique

packages/core/index.js

@@ -9,6 +9,17 @@
  * (...args) => f(g(h(...args))).
  */
 
+export function arrayUnique(array) {
+  const uniques = new Map();
+  array.forEach((element) => {
+    if (uniques.has(element)) {
+      return;
+    }
+    uniques.set(element, true);
+  })
+  return Array.from(uniques.keys());
+}
+
 export function compose(...funcs) {
   if (funcs.length === 0) {
     return arg => arg

packages/entity/traits/listed.js

@@ -1,5 +1,6 @@
 import * as I from 'immutable';
 
+import {arrayUnique} from '@avocado/core';
 import {Trait} from '@avocado/entity';
 import {Rectangle, Vector} from '@avocado/math';
 
@@ -105,14 +106,7 @@ export class Listed extends Trait {
           return node.data[2];
         });
         // Hitting multiple points for each entity can return duplicates.
-        const uniqueEntities = new Map();
-        entities.forEach((entity) => {
-          if (uniqueEntities.has(entity)) {
-            return;
-          }
-          uniqueEntities.set(entity, true);
-        })
-        return Array.from(uniqueEntities.keys());
+        return arrayUnique(entities);
       },
 
       resetQuadTreeNodes: () => {