Fix TS package not to override base no-restricted-syntax selectors

packages/typescript/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- **BREAKING:** Restrict usage of `with`, `in`, and sequence expressions, which should have been inherited from the base config but were mistakenly overridden ([#436](https://github.com/MetaMask/eslint-config/pull/436))
+
 ## [15.0.0]
 
 ### Changed

packages/typescript/rules-snapshot.json

@@ -226,6 +226,18 @@
   "no-redeclare": "off",
   "no-restricted-syntax": [
     "error",
+    {
+      "selector": "WithStatement",
+      "message": "With statements are not allowed"
+    },
+    {
+      "selector": "BinaryExpression[operator='in']",
+      "message": "The \"in\" operator is not allowed"
+    },
+    {
+      "selector": "SequenceExpression",
+      "message": "Sequence expressions are not allowed"
+    },
     {
       "selector": "PropertyDefinition[accessibility='private'], MethodDefinition[accessibility='private'], TSParameterProperty[accessibility='private']",
       "message": "Use a hash name instead."

packages/typescript/src/index.mjs

@@ -1,11 +1,42 @@
-import { createConfig } from '@metamask/eslint-config';
+import base, { createConfig } from '@metamask/eslint-config';
 import * as resolver from 'eslint-import-resolver-typescript';
 import importX from 'eslint-plugin-import-x';
 import jsdoc from 'eslint-plugin-jsdoc';
 // TODO: Look into why this doesn't resolve.
 // eslint-disable-next-line import-x/no-unresolved
 import typescript from 'typescript-eslint';
 
+/**
+ * Collects all options for a given array-valued rule across one or more flat
+ * config arrays, excluding the leading severity element.
+ *
+ * ESLint flat config does not merge array-valued rules across config objects —
+ * a later config silently replaces earlier ones. This helper makes it possible
+ * to extend an upstream rule configuration rather than copy-pasting its options.
+ *
+ * @param {string} ruleName - The rule to collect options for.
+ * @param {import('eslint').Linter.Config[][]} configs - Flat config arrays to
+ * collect options from.
+ * @returns {unknown[]} The options from all matching rule entries, with the
+ * leading severity element omitted.
+ */
+function collectExistingRuleOptions(ruleName, configs) {
+  return configs.flat().flatMap((config) => {
+    const rule = config.rules?.[ruleName];
+    if (!Array.isArray(rule)) {
+      return [];
+    }
+    // Rule entries are ['error' | 'warn' | number, ...options].
+    // Skip the first element (severity) and collect the rest.
+    return rule.slice(1);
+  });
+}
+
+const baseNoRestrictedSyntaxOptions = collectExistingRuleOptions(
+  'no-restricted-syntax',
+  base,
+);
+
 const config = createConfig({
   name: '@metamask/eslint-config-typescript',
 
@@ -234,6 +265,7 @@ const config = createConfig({
     // Prefer hash names over TypeScript's `private` modifier.
     'no-restricted-syntax': [
       'error',
+      ...baseNoRestrictedSyntaxOptions,
       {
         selector:
           "PropertyDefinition[accessibility='private'], MethodDefinition[accessibility='private'], TSParameterProperty[accessibility='private']",