fix: allow multiple calling of updateProps (#170)

* Changed updateProps to return the Promise created from
wrapper.setProps.
* Updated the `updateProps` test to make sure the function can be called
multiple times without producing errors.

src/__tests__/update-props.js

@@ -14,9 +14,11 @@ test('calling render with the same component but different props does not remoun
   expect(getByTestId('number-display')).toHaveTextContent('1')
 
   await updateProps({number: 2})
-
   expect(getByTestId('number-display')).toHaveTextContent('2')
 
+  await updateProps({number: 3})
+  expect(getByTestId('number-display')).toHaveTextContent('3')
+
   // Assert that, even after updating props, the component hasn't remounted,
   // meaning we are testing the same component instance we rendered initially.
   expect(getByTestId('instance-id')).toHaveTextContent('1')

src/vue-testing-library.js

@@ -80,10 +80,7 @@ function render(
     isUnmounted: () => wrapper.vm._isDestroyed,
     html: () => wrapper.html(),
     emitted: () => wrapper.emitted(),
-    updateProps: _ => {
-      wrapper.setProps(_)
-      return waitFor(() => {})
-    },
+    updateProps: _ => wrapper.setProps(_),
     ...getQueriesForElement(baseElement),
   }
 }