Improving tests

Author: David-Desmaisons

package.json

@@ -9,7 +9,7 @@
     "build:doc": "vue-cli-service build ./example/main.js --dest docs --mode development",
     "build": "vue-cli-service build --name vuedraggable --entry ./src/vuedraggable.js --target lib",
     "lint": "vue-cli-service lint src example",
-    "prepublishOnly": "npm run lint && npm run build",
+    "prepublishOnly": "npm run lint && npm run test:unit && npm run build",
     "test:unit": "vue-cli-service test:unit --coverage",
     "test:coverage": "vue-cli-service test:unit --coverage --verbose && codecov"
   },

tests/unit/draggable.node.spec.js

@@ -0,0 +1,8 @@
+/**
+ * @jest-environment node
+ */
+
+test('draggable can be required in a node environment', () => {
+  const draggable = require("@/vuedraggable");
+  expect(draggable).not.toBeNull();
+});