fix(setData): allow empty objects to be set fix #1704 (#1705)

* fix(setData): allow empty objects to be set

fixes #1704 

This is a tentative fix to show one possible solution, I can clean it up if you think it makes sense

* fix formatting

* test

Author: Haroenv

packages/test-utils/src/recursively-set-data.js

@@ -5,7 +5,11 @@ export function recursivelySetData(vm, target, data) {
     const val = data[key]
     const targetVal = target[key]
 
-    if (isPlainObject(val) && isPlainObject(targetVal)) {
+    if (
+      isPlainObject(val) &&
+      isPlainObject(targetVal) &&
+      Object.keys(val).length > 0
+    ) {
       recursivelySetData(vm, targetVal, val)
     } else {
       vm.$set(target, key, val)

test/specs/wrapper/setData.spec.js

@@ -320,4 +320,29 @@ describeWithShallowAndMount('setData', mountingMethod => {
     await wrapper.setData({ selectedDate: testDate })
     expect(wrapper.vm.selectedDate).toEqual(testDate)
   })
+
+  it('allows empty objects to be set', () => {
+    const TestComponent = {
+      data() {
+        return {
+          someKey: { someValue: true }
+        }
+      },
+      render(h) {
+        return h('span')
+      }
+    }
+
+    const wrapper = mountingMethod(TestComponent)
+
+    expect(wrapper.vm.$data).toEqual({ someKey: { someValue: true } })
+
+    wrapper.setData({ someKey: {} })
+
+    expect(wrapper.vm.$data).toEqual({ someKey: {} })
+
+    wrapper.setData({ someKey: { someValue: false } })
+
+    expect(wrapper.vm.$data).toEqual({ someKey: { someValue: false } })
+  })
 })