refactor: transform test/utils to ts

Author: myNameIsDu

test/utils/Subscription.spec.js renamed to test/utils/Subscription.spec.ts

@@ -15,6 +15,7 @@ describe('isPlainObject', () => {
     expect(isPlainObject(new Date())).toBe(false)
     expect(isPlainObject([1, 2, 3])).toBe(false)
     expect(isPlainObject(null)).toBe(false)
+    //@ts-expect-error
     expect(isPlainObject()).toBe(false)
     expect(isPlainObject({ x: 1, y: 2 })).toBe(true)
     expect(isPlainObject(Object.create(null))).toBe(true)