fix set diff

parcel-bundler · Dec 16, 2022 · 5ac33c9 · 5ac33c9
1 parent 3437f64
commit 5ac33c9
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Showing 2 changed files with 16 additions and 3 deletions.
diff --git a/packages/core/utils/src/collection.js b/packages/core/utils/src/collection.js
@@ -36,8 +36,9 @@ function sortEntry(entry: mixed) {
 
 export function setDifference<T>(a: Set<T>, b: Set<T>): Set<T> {
   let difference = new Set();
-  for (let e of a) {
-    if (!b.has(e)) {
+  let both = new Set([...a, ...b]);
+  for (let e of both) {
+    if (!b.has(e) || !a.has(e)) {
       difference.add(e);
     }
   }

diff --git a/packages/core/utils/test/collection.test.js b/packages/core/utils/test/collection.test.js
@@ -1,7 +1,11 @@
 // @flow
 
 import assert from 'assert';
-import {objectSortedEntries, objectSortedEntriesDeep} from '../src/collection';
+import {
+  objectSortedEntries,
+  objectSortedEntriesDeep,
+  setDifference,
+} from '../src/collection';
 
 describe('objectSortedEntries', () => {
   it('returns a sorted list of key/value tuples', () => {
@@ -38,3 +42,11 @@ describe('objectSortedEntriesDeep', () => {
     );
   });
 });
+describe('setDifference', () => {
+  it('returns a setDifference of two sets of T type', () => {
+    assert.deepEqual(
+      setDifference(new Set([1, 2, 3]), new Set([3, 4, 5])),
+      new Set([1, 2, 4, 5]),
+    );
+  });
+});