add rule

Author: ota-meshi

docs/configs/index.md

@@ -1034,7 +1034,7 @@ export default [
 disallow proposal ES2026 [Explicit Resource Management](https://github.com/tc39/proposal-explicit-resource-management)\
 ⚠️ This config will be changed in the minor versions of this plugin.
 
-This configs includes rules for [es-x/no-asyncdisposablestack](../rules/no-asyncdisposablestack.md), [es-x/no-disposablestack](../rules/no-disposablestack.md), and [es-x/no-suppressederror](../rules/no-suppressederror.md).
+This configs includes rules for [es-x/no-asyncdisposablestack](../rules/no-asyncdisposablestack.md), [es-x/no-disposablestack](../rules/no-disposablestack.md), [es-x/no-suppressederror](../rules/no-suppressederror.md), and [es-x/no-using-declarations](../rules/no-using-declarations.md).
 
 ### [Config (Flat Config)]
 

docs/rules/index.md

@@ -14,6 +14,7 @@ There is a config that enables the rules in this category: [`no-new-in-esnext`]
 | [es-x/no-asyncdisposablestack](./no-asyncdisposablestack.md) | disallow the `AsyncDisposableStack` class. |  |
 | [es-x/no-disposablestack](./no-disposablestack.md) | disallow the `DisposableStack` class. |  |
 | [es-x/no-suppressederror](./no-suppressederror.md) | disallow the `SuppressedError` class. |  |
+| [es-x/no-using-declarations](./no-using-declarations.md) | disallow `using` and `await using` declarations. |  |
 
 ## ES2025
 

docs/rules/no-using-declarations.md

@@ -0,0 +1,43 @@
+---
+title: "es-x/no-using-declarations"
+description: "disallow `using` and `await using` declarations"
+---
+
+# es-x/no-using-declarations
+> disallow `using` and `await using` declarations
+
+- ❗ <badge text="This rule has not been released yet." vertical="middle" type="error"> ***This rule has not been released yet.*** </badge>
+- ✅ The following configurations enable this rule: [no-explicit-resource-management] and [no-new-in-esnext]
+
+This rule reports ES2026 [`using` and `await using` declarations](https://github.com/tc39/proposal-explicit-resource-management) as errors.
+
+## 💡 Examples
+
+⛔ Examples of **incorrect** code for this rule:
+
+<eslint-playground type="bad">
+
+```js
+/*eslint es-x/no-using-declarations: error */
+
+// async disposal
+async function * g() {
+  using stream = acquireStream(); // block-scoped critical resource
+  // ...
+} // cleanup
+
+{
+  await using obj = g(); // block-scoped declaration
+  const r = await obj.next();
+} // calls finally blocks in `g`
+```
+
+</eslint-playground>
+
+## 📚 References
+
+- [Rule source](https://github.com/eslint-community/eslint-plugin-es-x/blob/master/lib/rules/no-using-declarations.js)
+- [Test source](https://github.com/eslint-community/eslint-plugin-es-x/blob/master/tests/lib/rules/no-using-declarations.js)
+
+[no-explicit-resource-management]: ../configs/index.md#no-explicit-resource-management
+[no-new-in-esnext]: ../configs/index.md#no-new-in-esnext

lib/configs/flat/no-explicit-resource-management.js

@@ -14,5 +14,6 @@ module.exports = {
         "es-x/no-asyncdisposablestack": "error",
         "es-x/no-disposablestack": "error",
         "es-x/no-suppressederror": "error",
+        "es-x/no-using-declarations": "error",
     },
 }

lib/configs/flat/no-new-in-esnext.js

@@ -15,6 +15,7 @@ module.exports = {
         "es-x/no-asyncdisposablestack": "error",
         "es-x/no-disposablestack": "error",
         "es-x/no-suppressederror": "error",
+        "es-x/no-using-declarations": "error",
         "es-x/no-dataview-prototype-getfloat16-setfloat16": "error",
         "es-x/no-dynamic-import-options": "error",
         "es-x/no-float16array": "error",

lib/configs/no-explicit-resource-management.js

@@ -10,5 +10,6 @@ module.exports = {
         "es-x/no-asyncdisposablestack": "error",
         "es-x/no-disposablestack": "error",
         "es-x/no-suppressederror": "error",
+        "es-x/no-using-declarations": "error",
     },
 }

lib/configs/no-new-in-esnext.js

@@ -11,6 +11,7 @@ module.exports = {
         "es-x/no-asyncdisposablestack": "error",
         "es-x/no-disposablestack": "error",
         "es-x/no-suppressederror": "error",
+        "es-x/no-using-declarations": "error",
         "es-x/no-dataview-prototype-getfloat16-setfloat16": "error",
         "es-x/no-dynamic-import-options": "error",
         "es-x/no-float16array": "error",

lib/index.js

@@ -460,6 +460,7 @@ module.exports = {
         "no-trailing-function-commas": require("./rules/no-trailing-function-commas"),
         "no-typed-arrays": require("./rules/no-typed-arrays"),
         "no-unicode-codepoint-escapes": require("./rules/no-unicode-codepoint-escapes"),
+        "no-using-declarations": require("./rules/no-using-declarations"),
         "no-weak-map": require("./rules/no-weak-map"),
         "no-weak-set": require("./rules/no-weak-set"),
         "no-weakrefs": require("./rules/no-weakrefs"),

lib/rules/no-using-declarations.js

@@ -0,0 +1,34 @@
+"use strict"
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow `using` and `await using` declarations",
+            category: "ES2026",
+            proposal: "explicit-resource-management",
+            recommended: false,
+            url: "http://eslint-community.github.io/eslint-plugin-es-x/rules/no-using-declarations.html",
+        },
+        fixable: null,
+        messages: {
+            forbidden: "ES2026 '{{kind}}' declarations are forbidden.",
+        },
+        schema: [],
+        type: "problem",
+    },
+    create(context) {
+        return {
+            VariableDeclaration(node) {
+                if (node.kind === "using" || node.kind === "await using") {
+                    context.report({
+                        node,
+                        messageId: "forbidden",
+                        data: {
+                            kind: node.kind,
+                        },
+                    })
+                }
+            },
+        }
+    },
+}

tests/lib/rules/no-using-declarations.js

@@ -0,0 +1,29 @@
+"use strict"
+
+const RuleTester = require("../../tester")
+const rule = require("../../../lib/rules/no-using-declarations.js")
+
+// if (!RuleTester.isSupported(2026)) {
+//     //eslint-disable-next-line no-console
+//     console.log("Skip the tests of no-using-declarations.")
+//     return
+// }
+
+new RuleTester({
+    languageOptions: {
+        sourceType: "module",
+        parser: require("@typescript-eslint/parser"), // espree does not support `using` yet.
+    },
+}).run("no-using-declarations", rule, {
+    valid: ["let x = y", "const x = y", "var x = y", "const x = await y"],
+    invalid: [
+        {
+            code: "using x = y",
+            errors: ["ES2026 'using' declarations are forbidden."],
+        },
+        {
+            code: "await using x = y",
+            errors: ["ES2026 'await using' declarations are forbidden."],
+        },
+    ],
+})