wip: code formatting nits continued

test/isWeakSet.spec.js

@@ -0,0 +1,40 @@
+import lodashStable from 'lodash';
+import { weakSet, falsey, stubFalse, args, slice, set, symbol, realm } from './utils';
+import isWeakSet from '../src/isWeakSet';
+
+describe('isWeakSet', () => {
+    it('should return `true` for weak sets', () => {
+        if (WeakSet) {
+            expect(isWeakSet(weakSet)).toBe(true);
+        }
+    });
+
+    it('should return `false` for non weak sets', () => {
+        const expected = lodashStable.map(falsey, stubFalse);
+
+        const actual = lodashStable.map(falsey, (value, index) =>
+            index ? isWeakSet(value) : isWeakSet(),
+        );
+
+        expect(actual).toEqual(expected);
+
+        expect(isWeakSet(args)).toBe(false);
+        expect(isWeakSet([1, 2, 3])).toBe(false);
+        expect(isWeakSet(true)).toBe(false);
+        expect(isWeakSet(new Date())).toBe(false);
+        expect(isWeakSet(new Error())).toBe(false);
+        expect(isWeakSet(slice)).toBe(false);
+        expect(isWeakSet({ a: 1 })).toBe(false);
+        expect(isWeakSet(1)).toBe(false);
+        expect(isWeakSet(/x/)).toBe(false);
+        expect(isWeakSet('a')).toBe(false);
+        expect(isWeakSet(set)).toBe(false);
+        expect(isWeakSet(symbol)).toBe(false);
+    });
+
+    it('should work with weak sets from another realm', () => {
+        if (realm.weakSet) {
+            expect(isWeakSet(realm.weakSet)).toBe(true);
+        }
+    });
+});