Fix linter

.eslintrc.cjs

@@ -5,7 +5,14 @@ module.exports = {
   root: true,
   extends: [
     "plugin:vue/essential",
+    "plugin:vue/strongly-recommended",
     "eslint:recommended",
     "@vue/eslint-config-prettier",
   ],
+  env: {
+    es2021: true,
+  },
+  parserOptions: {
+    ecmaVersion: "latest",
+  },
 };

example/src/components/NumberCounter.vue

@@ -20,7 +20,10 @@
 export default {
   name: "NumberCounter",
   props: {
-    value: Number,
+    value: {
+      type: Number,
+      required: true,
+    },
   },
   emits: ["input"],
   data() {

src/DragContainer.vue

@@ -26,14 +26,39 @@ export default {
     },
   },
   props: {
-    dragID: String,
-    x: Number,
-    y: Number,
-    w: Number,
-    h: Number,
-    data: Object,
-    context: String,
-    gridId: String,
+    dragID: {
+      type: String,
+      required: true,
+    },
+    x: {
+      type: Number,
+      required: true,
+    },
+    y: {
+      type: Number,
+      required: true,
+    },
+    w: {
+      type: Number,
+      required: true,
+    },
+    h: {
+      type: Number,
+      required: true,
+    },
+    data: {
+      type: Object,
+      required: false,
+      default: () => ({}),
+    },
+    context: {
+      type: String,
+      required: true,
+    },
+    gridId: {
+      type: String,
+      required: true,
+    },
     disabled: Boolean,
   },
   computed: {

src/DragGrid.vue

@@ -60,10 +60,12 @@ export default {
     posValidation: {
       type: Function,
       required: false,
+      default: undefined,
     },
     validateElement: {
       type: Function,
       required: false,
+      default: undefined,
     },
     value: {
       type: Array,