wip: code formatting nits continued

test/isNative.spec.js

@@ -0,0 +1,99 @@
+import lodashStable from 'lodash';
+
+import {
+    body,
+    create,
+    slice,
+    falsey,
+    stubFalse,
+    args,
+    symbol,
+    realm,
+    amd,
+    filePath,
+    emptyObject,
+    interopRequire,
+} from './utils';
+
+import isNative from '../src/isNative';
+import _baseEach from '../.internal/baseEach';
+
+describe('isNative', () => {
+    it('should return `true` for native methods', () => {
+        const values = [
+            Array,
+            body && body.cloneNode,
+            create,
+            root.encodeURI,
+            Promise,
+            slice,
+            Uint8Array,
+        ];
+        const expected = lodashStable.map(values, Boolean);
+        const actual = lodashStable.map(values, isNative);
+
+        expect(actual).toEqual(expected);
+    });
+
+    it('should return `false` for non-native methods', () => {
+        const expected = lodashStable.map(falsey, stubFalse);
+
+        const actual = lodashStable.map(falsey, (value, index) =>
+            index ? isNative(value) : isNative(),
+        );
+
+        expect(actual).toEqual(expected);
+
+        expect(isNative(args)).toBe(false);
+        expect(isNative([1, 2, 3])).toBe(false);
+        expect(isNative(true)).toBe(false);
+        expect(isNative(new Date())).toBe(false);
+        expect(isNative(new Error())).toBe(false);
+        expect(isNative({ a: 1 })).toBe(false);
+        expect(isNative(1)).toBe(false);
+        expect(isNative(/x/)).toBe(false);
+        expect(isNative('a')).toBe(false);
+        expect(isNative(symbol)).toBe(false);
+    });
+
+    it('should work with native functions from another realm', () => {
+        if (realm.element) {
+            expect(isNative(realm.element.cloneNode)).toBe(true);
+        }
+        if (realm.object) {
+            expect(isNative(realm.object.valueOf)).toBe(true);
+        }
+    });
+
+    xit('should throw an error if core-js is detected', () => {
+        const lodash = runInContext({
+            '__core-js_shared__': {},
+        });
+
+        expect(() => {
+            lodash.isNative(noop);
+        }).toThrow();
+    });
+
+    it('should detect methods masquerading as native (test in Node.js)', () => {
+        if (!amd && _baseEach) {
+            const path = require('path');
+            const basePath = path.dirname(filePath);
+            const uid = 'e0gvgyrad1jor';
+            const coreKey = '__core-js_shared__';
+            const fakeSrcKey = `Symbol(src)_1.${uid}`;
+
+            root[coreKey] = { keys: { IE_PROTO: `Symbol(IE_PROTO)_3.${uid}` } };
+            emptyObject(require.cache);
+
+            const baseIsNative = interopRequire(path.join(basePath, '_baseIsNative'));
+            expect(baseIsNative(slice)).toBe(true);
+
+            slice[fakeSrcKey] = `${slice}`;
+            expect(baseIsNative(slice)).toBe(false);
+
+            delete slice[fakeSrcKey];
+            delete root[coreKey];
+        }
+    });
+});