test: ensure Wrapper.setSelected() idempotency

Author: vvanpo

Diff for: test/specs/wrapper/setSelected.spec.js

@@ -39,6 +39,38 @@ describeWithShallowAndMount('setSelected', mountingMethod => {
     expect(wrapper.text()).to.contain('selectA')
   })
 
+  it('should trigger a change event on the parent <select>', () => {
+    const change = sinon.spy()
+
+    mountingMethod({
+      template: `
+        <select @change="change">
+          <option />
+          <option value="foo" />
+        </select>
+      `,
+      methods: { change },
+    }).findAll('option').at(1).setSelected()
+
+    expect(change).to.have.been.called
+  });
+
+  it('should not trigger an event if already selected', () => {
+    const change = sinon.spy()
+
+    mountingMethod({
+      template: `
+        <select @change="change">
+          <option />
+          <option selected value="foo" />
+        </select>
+      `,
+      methods: { change },
+    }).findAll('option').at(1).setSelected()
+
+    expect(change).not.to.have.been.called
+  });
+
   it('throws error if element is not valid', () => {
     const message = 'wrapper.setSelected() cannot be called on this element'