✅ Add tests

test/unit/specs/Doughnut.spec.js

@@ -0,0 +1,17 @@
+import Vue from 'vue'
+import DoughnutChart from 'src/examples/DoughnutExample'
+
+describe('DoughnutChart', () => {
+  it('should render a canvas', () => {
+    const vm = new Vue({
+      el: 'body',
+      replace: false,
+      template: '<doughnut-chart></doughnut-chart>',
+      components: { DoughnutChart }
+    })
+    expect(vm.$el.querySelector('#doughnut-chart')).not.to.be.an('undefined')
+    expect(vm.$el.querySelector('canvas')).not.to.be.an('undefined')
+    expect(vm.$el.querySelector('canvas')).not.to.be.an('null')
+    expect(vm.$el.querySelector('canvas')).to.exist
+  })
+})