wip: code formatting nits continued

test/isWeakMap.spec.js

@@ -0,0 +1,49 @@
+import lodashStable from 'lodash';
+import { weakMap, falsey, stubFalse, args, slice, map, symbol, realm } from './utils';
+import isWeakMap from '../src/isWeakMap';
+
+describe('isWeakMap', () => {
+    it('should return `true` for weak maps', () => {
+        if (WeakMap) {
+            expect(isWeakMap(weakMap)).toBe(true);
+        }
+    });
+
+    it('should return `false` for non weak maps', () => {
+        const expected = lodashStable.map(falsey, stubFalse);
+
+        const actual = lodashStable.map(falsey, (value, index) =>
+            index ? isWeakMap(value) : isWeakMap(),
+        );
+
+        expect(actual).toEqual(expected);
+
+        expect(isWeakMap(args)).toBe(false);
+        expect(isWeakMap([1, 2, 3])).toBe(false);
+        expect(isWeakMap(true)).toBe(false);
+        expect(isWeakMap(new Date())).toBe(false);
+        expect(isWeakMap(new Error())).toBe(false);
+        expect(isWeakMap(slice)).toBe(false);
+        expect(isWeakMap({ a: 1 })).toBe(false);
+        expect(isWeakMap(map)).toBe(false);
+        expect(isWeakMap(1)).toBe(false);
+        expect(isWeakMap(/x/)).toBe(false);
+        expect(isWeakMap('a')).toBe(false);
+        expect(isWeakMap(symbol)).toBe(false);
+    });
+
+    it('should work for objects with a non-function `constructor` (test in IE 11)', () => {
+        const values = [false, true];
+        const expected = lodashStable.map(values, stubFalse);
+
+        const actual = lodashStable.map(values, (value) => isWeakMap({ constructor: value }));
+
+        expect(actual).toEqual(expected);
+    });
+
+    it('should work with weak maps from another realm', () => {
+        if (realm.weakMap) {
+            expect(isWeakMap(realm.weakMap)).toBe(true);
+        }
+    });
+});