feat: add ecmaVersion: 2026, parsing using and await using (#19832)

mdjermanovic · web-flow · commit f686fcb51e47 · 2025-06-13T06:49:43.000+02:00
* feat: add `ecmaVersion: 2026`, parsing `using` and `await using`

* bump eslint-visitor-keys
diff --git a/conf/ecma-version.js b/conf/ecma-version.js
@@ -9,7 +9,7 @@
  * The latest ECMAScript version supported by ESLint.
  * @type {number} year-based ECMAScript version
  */
-const LATEST_ECMA_VERSION = 2025;
+const LATEST_ECMA_VERSION = 2026;
 
 module.exports = {
 	LATEST_ECMA_VERSION,
diff --git a/conf/globals.js b/conf/globals.js
@@ -139,6 +139,13 @@ const es2025 = {
 	Iterator: false,
 };
 
+const es2026 = {
+	...es2025,
+	AsyncDisposableStack: false,
+	DisposableStack: false,
+	SuppressedError: false,
+};
+
 //-----------------------------------------------------------------------------
 // Exports
 //-----------------------------------------------------------------------------
@@ -158,4 +165,5 @@ module.exports = {
 	es2023,
 	es2024,
 	es2025,
+	es2026,
 };
diff --git a/docs/src/use/configure/language-options-deprecated.md b/docs/src/use/configure/language-options-deprecated.md
@@ -193,7 +193,7 @@ By the same token, supporting ES6 syntax is not the same as supporting new ES6 g
 
 Parser options are set in your `.eslintrc.*` file with the `parserOptions` property. The available options are:
 
-- `ecmaVersion` - set to 3, 5 (default), 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 to specify the version of ECMAScript syntax you want to use. You can also set it to 2015 (same as 6), 2016 (same as 7), 2017 (same as 8), 2018 (same as 9), 2019 (same as 10), 2020 (same as 11), 2021 (same as 12), 2022 (same as 13), 2023 (same as 14), 2024 (same as 15), or 2025 (same as 16) to use the year-based naming. You can also set `"latest"` to use the most recently supported version.
+- `ecmaVersion` - set to 3, 5 (default), 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17 to specify the version of ECMAScript syntax you want to use. You can also set it to 2015 (same as 6), 2016 (same as 7), 2017 (same as 8), 2018 (same as 9), 2019 (same as 10), 2020 (same as 11), 2021 (same as 12), 2022 (same as 13), 2023 (same as 14), 2024 (same as 15), 2025 (same as 16), or 2026 (same as 17) to use the year-based naming. You can also set `"latest"` to use the most recently supported version.
 - `sourceType` - set to `"script"` (default) or `"module"` if your code is in ECMAScript modules.
 - `allowReserved` - allow the use of reserved words as identifiers (if `ecmaVersion` is 3).
 - `ecmaFeatures` - an object indicating which additional language features you'd like to use:
diff --git a/lib/types/index.d.ts b/lib/types/index.d.ts
@@ -1416,6 +1416,7 @@ export namespace Linter {
 		| 14
 		| 15
 		| 16
+		| 17
 		| 2015
 		| 2016
 		| 2017
@@ -1427,6 +1428,7 @@ export namespace Linter {
 		| 2023
 		| 2024
 		| 2025
+		| 2026
 		| "latest";
 
 	/**
diff --git a/package.json b/package.json
@@ -122,9 +122,9 @@
     "cross-spawn": "^7.0.6",
     "debug": "^4.3.2",
     "escape-string-regexp": "^4.0.0",
-    "eslint-scope": "^8.3.0",
-    "eslint-visitor-keys": "^4.2.0",
-    "espree": "^10.3.0",
+    "eslint-scope": "^8.4.0",
+    "eslint-visitor-keys": "^4.2.1",
+    "espree": "^10.4.0",
     "esquery": "^1.5.0",
     "esutils": "^2.0.2",
     "fast-deep-equal": "^3.1.3",
diff --git a/tests/lib/linter/linter.js b/tests/lib/linter/linter.js
@@ -6090,7 +6090,7 @@ var a = "test2";
 			});
 
 			it("supports ECMAScript version 'latest'", () => {
-				const messages = linter.verify("let x = /(?<x>a)|(?<x>b)/;", {
+				const messages = linter.verify("{ using x = foo(); }", {
 					parserOptions: { ecmaVersion: "latest" },
 				});
 				const suppressedMessages = linter.getSuppressedMessages();
@@ -9173,9 +9173,7 @@ describe("Linter with FlatConfigArray", () => {
 				});
 
 				it("ecmaVersion should be 'latest' by default", () => {
-					const messages = linter.verify(
-						"let x = /(?<x>a)|(?<x>b)/;",
-					); // ECMAScript 2025 syntax
+					const messages = linter.verify("{ using x = foo(); }"); // ECMAScript 2026 syntax
 					const suppressedMessages = linter.getSuppressedMessages();
 
 					assert.strictEqual(messages.length, 0); // No parsing errors
diff --git a/tests/lib/rules/no-restricted-syntax.js b/tests/lib/rules/no-restricted-syntax.js
@@ -350,5 +350,41 @@ ruleTester.run("no-restricted-syntax", rule, {
 				},
 			],
 		},
+
+		{
+			code: "{ using x = foo(); }",
+			options: ["VariableDeclaration[kind='using']"],
+			languageOptions: {
+				ecmaVersion: 2026,
+			},
+			errors: [
+				{
+					messageId: "restrictedSyntax",
+					data: {
+						message:
+							"Using 'VariableDeclaration[kind='using']' is not allowed.",
+					},
+					type: "VariableDeclaration",
+				},
+			],
+		},
+
+		{
+			code: "async function f() { await using x = foo(); }",
+			options: ["VariableDeclaration[kind='await using']"],
+			languageOptions: {
+				ecmaVersion: 17,
+			},
+			errors: [
+				{
+					messageId: "restrictedSyntax",
+					data: {
+						message:
+							"Using 'VariableDeclaration[kind='await using']' is not allowed.",
+					},
+					type: "VariableDeclaration",
+				},
+			],
+		},
 	],
 });
diff --git a/tests/lib/rules/no-undef.js b/tests/lib/rules/no-undef.js
@@ -224,6 +224,10 @@ ruleTester.run("no-undef", rule, {
 			code: "[Float16Array, Iterator]",
 			languageOptions: { ecmaVersion: 2025 },
 		},
+		{
+			code: "AsyncDisposableStack; DisposableStack; SuppressedError",
+			languageOptions: { ecmaVersion: 2026 },
+		},
 	],
 	invalid: [
 		{
diff --git a/tests/lib/types/types.test.ts b/tests/lib/types/types.test.ts
@@ -930,6 +930,7 @@ linter.verify(SOURCE, { parserOptions: { ecmaVersion: 2022 } }, "test.js");
 linter.verify(SOURCE, { parserOptions: { ecmaVersion: 2023 } }, "test.js");
 linter.verify(SOURCE, { parserOptions: { ecmaVersion: 2024 } }, "test.js");
 linter.verify(SOURCE, { parserOptions: { ecmaVersion: 2025 } }, "test.js");
+linter.verify(SOURCE, { parserOptions: { ecmaVersion: 2026 } }, "test.js");
 linter.verify(SOURCE, { parserOptions: { ecmaVersion: "latest" } }, "test.js");
 linter.verify(
 	SOURCE,
@@ -1180,6 +1181,11 @@ linterWithFlatConfig.verify(
 	[{ languageOptions: { ecmaVersion: 2025 } }],
 	"test.js",
 );
+linterWithFlatConfig.verify(
+	SOURCE,
+	[{ languageOptions: { ecmaVersion: 2026 } }],
+	"test.js",
+);
 linterWithFlatConfig.verify(
 	SOURCE,
 	[{ languageOptions: { ecmaVersion: "latest" } }],
@@ -1345,6 +1351,11 @@ linterWithEslintrcConfig.verify(
 	{ parserOptions: { ecmaVersion: 2025 } },
 	"test.js",
 );
+linterWithEslintrcConfig.verify(
+	SOURCE,
+	{ parserOptions: { ecmaVersion: 2026 } },
+	"test.js",
+);
 linterWithEslintrcConfig.verify(
 	SOURCE,
 	{ parserOptions: { ecmaVersion: "latest" } },

-Original file line number
+Diff line change
 		| 14
 		| 15
 		| 16
 +		| 17
 		| 2015
 		| 2016
 		| 2017
 		| 2023
 		| 2024
 		| 2025
 +		| 2026
 		| "latest";
 	/**