rule no-on

config/future.js

@@ -3,5 +3,6 @@ module.exports = {
     "effector/prefer-sample-over-forward-with-mapping": "off",
     "effector/no-forward": "warn",
     "effector/no-guard": "warn",
+    "effector/no-on": "error",
   },
 };

docs/rules/no-on.md

@@ -0,0 +1,20 @@
+# effector/no-on
+
+This rule forbids `.on` chaining on effector store.
+
+---
+
+```ts
+const event = createEvent()
+// 👎 could be replaced
+const $store = createStore(null).on(event, (_, s) => s)
+
+
+const event = createEvent()
+const $store = createStore(null)
+// 👍 makes sense
+sample({
+    clock: event,
+    target: $store
+})
+```

index.js

@@ -18,6 +18,7 @@ module.exports = {
     "mandatory-scope-binding": require("./rules/mandatory-scope-binding/mandatory-scope-binding"),
     "prefer-useUnit": require("./rules/prefer-useUnit/prefer-useUnit"),
     "no-patronum-debug": require("./rules/no-patronum-debug/no-patronum-debug"),
+    "no-on": require("./rules/no-on/no-on"),
   },
   configs: {
     recommended: require("./config/recommended"),

rules/no-on/examples/correct.ts

@@ -0,0 +1,10 @@
+import { createEvent, createStore, sample } from "effector";
+
+const event = createEvent();
+
+const $store = createStore(null);
+
+sample({
+  clock: event,
+  target: $store,
+});

rules/no-on/examples/incorrect-chaining.ts

@@ -0,0 +1,9 @@
+import { createEvent, createStore } from "effector";
+
+const event = createEvent();
+const event2 = createEvent();
+
+const $store = createStore(null)
+  .on(event, (_, s) => s)
+  .on(event2, (_, s) => s)
+  .on(event, (_, s) => s);

rules/no-on/examples/incorrect.ts

@@ -0,0 +1,5 @@
+import { createEvent, createStore } from "effector";
+
+const event = createEvent();
+
+const $store = createStore(null).on(event, (_, s) => s);

rules/no-on/no-on.js

@@ -0,0 +1,69 @@
+const { createLinkToRule } = require("../../utils/create-link-to-rule");
+const {
+  traverseNestedObjectNode,
+} = require("../../utils/traverse-nested-object-node");
+const { is } = require("../../utils/is");
+const { ESLintUtils } = require("@typescript-eslint/utils");
+
+module.exports = {
+  meta: {
+    type: "problem",
+    docs: {
+      description: "Forbids `.on` chaining on effector store.",
+      category: "Quality",
+      recommended: true,
+      url: createLinkToRule("no-on"),
+    },
+    messages: {
+      noOn: "Method `.on` is forbidden on any effector store.",
+    },
+    schema: [],
+  },
+  create(context) {
+    let parserServices;
+    try {
+      parserServices = ESLintUtils.getParserServices(context);
+    } catch (err) {
+      // no types information
+    }
+
+    if (!parserServices?.program) return {};
+
+    return {
+      'CallExpression[callee.property.name="on"]'(node) {
+        const storeObject = traverseNestedObjectNode(
+          getNestedCallee(node) ?? getAssignedVariable(node)
+        );
+
+        if (!is.store({ context, node: storeObject })) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "noOn",
+        });
+      },
+    };
+  },
+};
+
+function getNestedCallee(node) {
+  const { callee } = node;
+
+  if (callee.object?.type === "CallExpression") {
+    return getNestedCallee(callee.object);
+  }
+
+  return callee.object;
+}
+
+function getAssignedVariable(node) {
+  const { parent } = node;
+
+  if (parent.type === "VariableDeclarator") {
+    return parent;
+  }
+
+  return getAssignedVariable(parent);
+}

rules/no-on/no-on.md

@@ -0,0 +1 @@
+https://eslint.effector.dev/rules/no-on.html

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

@@ -0,0 +1,53 @@
+const { RuleTester } = require("@typescript-eslint/rule-tester");
+const { join } = require("path");
+
+const { readExample } = require("../../utils/read-example");
+const rule = require("./no-on");
+
+const ruleTester = new RuleTester({
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    ecmaVersion: 2020,
+    sourceType: "module",
+    project: "./tsconfig.json",
+    tsconfigRootDir: join(__dirname, ".."),
+  },
+});
+
+const readExampleForTheRule = (name) => ({
+  code: readExample(__dirname, name),
+  filename: join(__dirname, "examples", name),
+});
+
+ruleTester.run("effector/no-on.ts.test", rule, {
+  valid: ["correct.ts"].map(readExampleForTheRule),
+
+  invalid: [
+    ...["incorrect.ts"].map(readExampleForTheRule).map((result) => ({
+      ...result,
+      errors: [
+        {
+          messageId: "noOn",
+          type: "CallExpression",
+        },
+      ],
+    })),
+    ...["incorrect-chaining.ts"].map(readExampleForTheRule).map((result) => ({
+      ...result,
+      errors: [
+        {
+          messageId: "noOn",
+          type: "CallExpression",
+        },
+        {
+          messageId: "noOn",
+          type: "CallExpression",
+        },
+        {
+          messageId: "noOn",
+          type: "CallExpression",
+        },
+      ],
+    })),
+  ],
+});