Fix no-duplicate-on error messages during development in IDEA

Author: igorkamyshev

rules/no-duplicate-on/examples/correct-with-empty-on.ts

@@ -0,0 +1,6 @@
+import { createEvent, createStore } from "effector";
+
+const $store = createStore(1);
+
+// Yeah, it's incorrect TS code, but it isn't this plugin's business
+$store.on();

rules/no-duplicate-on/no-duplicate-on.js

@@ -101,6 +101,10 @@ module.exports = {
 };
 
 function normalizePossibleArrayNode(node) {
+  if (!node) {
+    return [];
+  }
+
   if (node.type === "ArrayExpression") {
     return node.elements;
   }

rules/no-duplicate-on/no-duplicate-on.ts.test.js

@@ -25,6 +25,7 @@ ruleTester.run("effector/no-duplicate-on.ts.test", rule, {
     "correct.ts",
     "correct-with-scopes.ts",
     "correct-with-nesting.ts",
+    "correct-with-empty-on.ts",
   ].map(readExampleForTheRule),
   invalid: ["incorrect-with-invalid-naming.ts"]
     .map(readExampleForTheRule)