From 8e157655206721f1dfe50ade6339b98448c1052b Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Wed, 7 May 2025 18:05:56 -0600
Subject: [PATCH 01/15] poc

---
 packages/eslint-plugin/raw-plugin.d.ts        | 28 +++++----
 packages/typescript-eslint/src/index.ts       | 60 ++++++++++++-------
 .../tests/defineConfig-interop.test.ts        | 16 +++++
 3 files changed, 71 insertions(+), 33 deletions(-)
 create mode 100644 packages/typescript-eslint/tests/defineConfig-interop.test.ts

diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index 25a093aba902..b233c2fdac77 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -2,21 +2,23 @@ import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
 
 import type plugin from './index';
 
+import type * as eslintConfigHelpers from '@eslint/config-helpers';
+
 declare const cjsExport: {
   flatConfigs: {
-    'flat/all': FlatConfig.ConfigArray;
-    'flat/base': FlatConfig.Config;
-    'flat/disable-type-checked': FlatConfig.Config;
-    'flat/eslint-recommended': FlatConfig.Config;
-    'flat/recommended': FlatConfig.ConfigArray;
-    'flat/recommended-type-checked': FlatConfig.ConfigArray;
-    'flat/recommended-type-checked-only': FlatConfig.ConfigArray;
-    'flat/strict': FlatConfig.ConfigArray;
-    'flat/strict-type-checked': FlatConfig.ConfigArray;
-    'flat/strict-type-checked-only': FlatConfig.ConfigArray;
-    'flat/stylistic': FlatConfig.ConfigArray;
-    'flat/stylistic-type-checked': FlatConfig.ConfigArray;
-    'flat/stylistic-type-checked-only': FlatConfig.ConfigArray;
+    'flat/all': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/base': eslintConfigHelpers.Config;
+    'flat/disable-type-checked': eslintConfigHelpers.Config;
+    'flat/eslint-recommended': eslintConfigHelpers.Config;
+    'flat/recommended': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/recommended-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/recommended-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/strict': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/strict-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/strict-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/stylistic': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/stylistic-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/stylistic-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
   };
   parser: FlatConfig.Parser;
   plugin: typeof plugin;
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 86870c855cd0..b3c8b745f4c9 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -6,6 +6,8 @@ import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw
 
 import { config } from './config-helper';
 
+import type * as eslintConfigHelpers from '@eslint/config-helpers';
+
 export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
 
 /*
@@ -31,30 +33,31 @@ use our new package); however legacy configs consumed via `@eslint/eslintrc`
 would never be able to satisfy this constraint and thus users would be blocked
 from using them.
 */
-export const plugin: TSESLint.FlatConfig.Plugin = pluginBase as Omit<
-  typeof pluginBase,
-  'configs'
->;
+export const plugin = pluginBase as unknown as eslintConfigHelpers.Plugin;
 
 export const configs = {
   /**
    * Enables each the rules provided as a part of typescript-eslint. Note that many rules are not applicable in all codebases, or are meant to be configured.
    * @see {@link https://typescript-eslint.io/users/configs#all}
    */
-  all: rawPlugin.flatConfigs['flat/all'],
+  all: rawPlugin.flatConfigs[
+    'flat/all'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * A minimal ruleset that sets only the required parser and plugin options needed to run typescript-eslint.
    * We don't recommend using this directly; instead, extend from an earlier recommended rule.
    * @see {@link https://typescript-eslint.io/users/configs#base}
    */
-  base: rawPlugin.flatConfigs['flat/base'],
+  base: rawPlugin.flatConfigs['flat/base'] as eslintConfigHelpers.Config,
 
   /**
    * A utility ruleset that will disable type-aware linting and all type-aware rules available in our project.
    * @see {@link https://typescript-eslint.io/users/configs#disable-type-checked}
    */
-  disableTypeChecked: rawPlugin.flatConfigs['flat/disable-type-checked'],
+  disableTypeChecked: rawPlugin.flatConfigs[
+    'flat/disable-type-checked'
+  ] as eslintConfigHelpers.Config,
 
   /**
    * This is a compatibility ruleset that:
@@ -62,64 +65,81 @@ export const configs = {
    * - enables rules that make sense due to TS's typechecking / transpilation.
    * @see {@link https://typescript-eslint.io/users/configs/#eslint-recommended}
    */
-  eslintRecommended: rawPlugin.flatConfigs['flat/eslint-recommended'],
+  eslintRecommended: rawPlugin.flatConfigs[
+    'flat/eslint-recommended'
+  ] as eslintConfigHelpers.Config,
 
   /**
    * Recommended rules for code correctness that you can drop in without additional configuration.
    * @see {@link https://typescript-eslint.io/users/configs#recommended}
    */
-  recommended: rawPlugin.flatConfigs['flat/recommended'],
+  recommended: rawPlugin.flatConfigs[
+    'flat/recommended'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * Contains all of `recommended` along with additional recommended rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked}
    */
-  recommendedTypeChecked:
-    rawPlugin.flatConfigs['flat/recommended-type-checked'],
+  recommendedTypeChecked: rawPlugin.flatConfigs[
+    'flat/recommended-type-checked'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * A version of `recommended` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked-only}
    */
-  recommendedTypeCheckedOnly:
-    rawPlugin.flatConfigs['flat/recommended-type-checked-only'],
+  recommendedTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/recommended-type-checked-only'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * Contains all of `recommended`, as well as additional strict rules that can also catch bugs.
    * @see {@link https://typescript-eslint.io/users/configs#strict}
    */
-  strict: rawPlugin.flatConfigs['flat/strict'],
+  strict: rawPlugin.flatConfigs[
+    'flat/strict'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * Contains all of `recommended`, `recommended-type-checked`, and `strict`, along with additional strict rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked}
    */
-  strictTypeChecked: rawPlugin.flatConfigs['flat/strict-type-checked'],
+  strictTypeChecked: rawPlugin.flatConfigs[
+    'flat/strict-type-checked'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * A version of `strict` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked-only}
    */
-  strictTypeCheckedOnly: rawPlugin.flatConfigs['flat/strict-type-checked-only'],
+  strictTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/strict-type-checked-only'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * Rules considered to be best practice for modern TypeScript codebases, but that do not impact program logic.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic}
    */
-  stylistic: rawPlugin.flatConfigs['flat/stylistic'],
+  stylistic: rawPlugin.flatConfigs[
+    'flat/stylistic'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * Contains all of `stylistic`, along with additional stylistic rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked}
    */
-  stylisticTypeChecked: rawPlugin.flatConfigs['flat/stylistic-type-checked'],
+  stylisticTypeChecked: rawPlugin.flatConfigs[
+    'flat/stylistic-type-checked'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 
   /**
    * A version of `stylistic` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked-only}
    */
-  stylisticTypeCheckedOnly:
-    rawPlugin.flatConfigs['flat/stylistic-type-checked-only'],
+  stylisticTypeCheckedOnly: rawPlugin.flatConfigs[
+    'flat/stylistic-type-checked-only'
+  ] as eslintConfigHelpers.ConfigWithExtendsArray,
 };
 
 export type Config = TSESLint.FlatConfig.ConfigFile;
diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test.ts b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
new file mode 100644
index 000000000000..e35c8723e697
--- /dev/null
+++ b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
@@ -0,0 +1,16 @@
+import { defineConfig } from 'eslint/config';
+import * as tseslint from '../src/index';
+
+describe('tseslint.config() should be replaceable with defineConfig()', () => {
+  it('should work with recommended setup', () => {
+    defineConfig(tseslint.configs.recommended);
+  });
+
+  it('should allow manual assignment of the plugin', () => {
+    defineConfig({
+      plugins: {
+        ts: tseslint.plugin,
+      },
+    });
+  });
+});

From a0775f0f5277baa7df670092dc67567489c179bf Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Wed, 7 May 2025 18:16:25 -0600
Subject: [PATCH 02/15] more

---
 packages/eslint-plugin/raw-plugin.d.ts        | 23 +++++++-------
 packages/typescript-eslint/src/index.ts       | 30 +++++++++----------
 .../typescript-eslint/tests/configs.test.ts   | 26 ++++++++--------
 3 files changed, 39 insertions(+), 40 deletions(-)

diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index b233c2fdac77..5095ecaf23f1 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -1,24 +1,23 @@
+import type * as eslintConfigHelpers from '@eslint/config-helpers';
 import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
 
 import type plugin from './index';
 
-import type * as eslintConfigHelpers from '@eslint/config-helpers';
-
 declare const cjsExport: {
   flatConfigs: {
-    'flat/all': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/all': eslintConfigHelpers.Config[];
     'flat/base': eslintConfigHelpers.Config;
     'flat/disable-type-checked': eslintConfigHelpers.Config;
     'flat/eslint-recommended': eslintConfigHelpers.Config;
-    'flat/recommended': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/recommended-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/recommended-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/strict': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/strict-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/strict-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/stylistic': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/stylistic-type-checked': eslintConfigHelpers.ConfigWithExtendsArray;
-    'flat/stylistic-type-checked-only': eslintConfigHelpers.ConfigWithExtendsArray;
+    'flat/recommended': eslintConfigHelpers.Config[];
+    'flat/recommended-type-checked': eslintConfigHelpers.Config[];
+    'flat/recommended-type-checked-only': eslintConfigHelpers.Config[];
+    'flat/strict': eslintConfigHelpers.Config[];
+    'flat/strict-type-checked': eslintConfigHelpers.Config[];
+    'flat/strict-type-checked-only': eslintConfigHelpers.Config[];
+    'flat/stylistic': eslintConfigHelpers.Config[];
+    'flat/stylistic-type-checked': eslintConfigHelpers.Config[];
+    'flat/stylistic-type-checked-only': eslintConfigHelpers.Config[];
   };
   parser: FlatConfig.Parser;
   plugin: typeof plugin;
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index b3c8b745f4c9..6f94a309eed0 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -1,3 +1,5 @@
+import type * as eslintConfigHelpers from '@eslint/config-helpers';
+
 // see the comment in config-helper.ts for why this doesn't use /ts-eslint
 import type { TSESLint } from '@typescript-eslint/utils';
 
@@ -6,8 +8,6 @@ import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw
 
 import { config } from './config-helper';
 
-import type * as eslintConfigHelpers from '@eslint/config-helpers';
-
 export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
 
 /*
@@ -35,14 +35,13 @@ from using them.
 */
 export const plugin = pluginBase as unknown as eslintConfigHelpers.Plugin;
 
+/* eslint-disable @typescript-eslint/no-unnecessary-type-assertion -- These "unnecessary" assertions work around "requires explicit type annotation" errors. */
 export const configs = {
   /**
    * Enables each the rules provided as a part of typescript-eslint. Note that many rules are not applicable in all codebases, or are meant to be configured.
    * @see {@link https://typescript-eslint.io/users/configs#all}
    */
-  all: rawPlugin.flatConfigs[
-    'flat/all'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  all: rawPlugin.flatConfigs['flat/all'] as eslintConfigHelpers.Config[],
 
   /**
    * A minimal ruleset that sets only the required parser and plugin options needed to run typescript-eslint.
@@ -75,7 +74,7 @@ export const configs = {
    */
   recommended: rawPlugin.flatConfigs[
     'flat/recommended'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * Contains all of `recommended` along with additional recommended rules that require type information.
@@ -83,7 +82,7 @@ export const configs = {
    */
   recommendedTypeChecked: rawPlugin.flatConfigs[
     'flat/recommended-type-checked'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * A version of `recommended` that only contains type-checked rules and disables of any corresponding core ESLint rules.
@@ -91,15 +90,13 @@ export const configs = {
    */
   recommendedTypeCheckedOnly: rawPlugin.flatConfigs[
     'flat/recommended-type-checked-only'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * Contains all of `recommended`, as well as additional strict rules that can also catch bugs.
    * @see {@link https://typescript-eslint.io/users/configs#strict}
    */
-  strict: rawPlugin.flatConfigs[
-    'flat/strict'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  strict: rawPlugin.flatConfigs['flat/strict'] as eslintConfigHelpers.Config[],
 
   /**
    * Contains all of `recommended`, `recommended-type-checked`, and `strict`, along with additional strict rules that require type information.
@@ -107,7 +104,7 @@ export const configs = {
    */
   strictTypeChecked: rawPlugin.flatConfigs[
     'flat/strict-type-checked'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * A version of `strict` that only contains type-checked rules and disables of any corresponding core ESLint rules.
@@ -115,7 +112,7 @@ export const configs = {
    */
   strictTypeCheckedOnly: rawPlugin.flatConfigs[
     'flat/strict-type-checked-only'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * Rules considered to be best practice for modern TypeScript codebases, but that do not impact program logic.
@@ -123,7 +120,7 @@ export const configs = {
    */
   stylistic: rawPlugin.flatConfigs[
     'flat/stylistic'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * Contains all of `stylistic`, along with additional stylistic rules that require type information.
@@ -131,7 +128,7 @@ export const configs = {
    */
   stylisticTypeChecked: rawPlugin.flatConfigs[
     'flat/stylistic-type-checked'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 
   /**
    * A version of `stylistic` that only contains type-checked rules and disables of any corresponding core ESLint rules.
@@ -139,8 +136,9 @@ export const configs = {
    */
   stylisticTypeCheckedOnly: rawPlugin.flatConfigs[
     'flat/stylistic-type-checked-only'
-  ] as eslintConfigHelpers.ConfigWithExtendsArray,
+  ] as eslintConfigHelpers.Config[],
 };
+/* eslint-enable @typescript-eslint/no-unnecessary-type-assertion */
 
 export type Config = TSESLint.FlatConfig.ConfigFile;
 
diff --git a/packages/typescript-eslint/tests/configs.test.ts b/packages/typescript-eslint/tests/configs.test.ts
index 742178196c81..3be135ea1e57 100644
--- a/packages/typescript-eslint/tests/configs.test.ts
+++ b/packages/typescript-eslint/tests/configs.test.ts
@@ -5,7 +5,7 @@ import type {
 
 import rules from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/rules';
 
-import plugin from '../src/index';
+import tseslint from '../src/index';
 
 const RULE_NAME_PREFIX = '@typescript-eslint/';
 const EXTENSION_RULES = Object.entries(rules)
@@ -107,7 +107,7 @@ function itHasBaseRulesOverriden(
 }
 
 describe('all.ts', () => {
-  const unfilteredConfigRules = plugin.configs.all[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.all[2]?.rules;
 
   it('contains all of the rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -125,7 +125,7 @@ describe('all.ts', () => {
 });
 
 describe('disable-type-checked.ts', () => {
-  const unfilteredConfigRules = plugin.configs.disableTypeChecked.rules;
+  const unfilteredConfigRules = tseslint.configs.disableTypeChecked.rules;
 
   it('disables all type checked rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -141,7 +141,7 @@ describe('disable-type-checked.ts', () => {
 });
 
 describe('recommended.ts', () => {
-  const unfilteredConfigRules = plugin.configs.recommended[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.recommended[2]?.rules;
 
   it('contains all recommended rules, excluding type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -160,7 +160,8 @@ describe('recommended.ts', () => {
 });
 
 describe('recommended-type-checked.ts', () => {
-  const unfilteredConfigRules = plugin.configs.recommendedTypeChecked[2]?.rules;
+  const unfilteredConfigRules =
+    tseslint.configs.recommendedTypeChecked[2]?.rules;
 
   it('contains all recommended rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -179,7 +180,7 @@ describe('recommended-type-checked.ts', () => {
 
 describe('recommended-type-checked-only.ts', () => {
   const unfilteredConfigRules =
-    plugin.configs.recommendedTypeCheckedOnly[2]?.rules;
+    tseslint.configs.recommendedTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked recommended rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -198,7 +199,7 @@ describe('recommended-type-checked-only.ts', () => {
 });
 
 describe('strict.ts', () => {
-  const unfilteredConfigRules = plugin.configs.strict[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.strict[2]?.rules;
 
   it('contains all strict rules, excluding type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -218,7 +219,7 @@ describe('strict.ts', () => {
 });
 
 describe('strict-type-checked.ts', () => {
-  const unfilteredConfigRules = plugin.configs.strictTypeChecked[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.strictTypeChecked[2]?.rules;
 
   it('contains all strict rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -236,7 +237,8 @@ describe('strict-type-checked.ts', () => {
 });
 
 describe('strict-type-checked-only.ts', () => {
-  const unfilteredConfigRules = plugin.configs.strictTypeCheckedOnly[2]?.rules;
+  const unfilteredConfigRules =
+    tseslint.configs.strictTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked strict rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -256,7 +258,7 @@ describe('strict-type-checked-only.ts', () => {
 });
 
 describe('stylistic.ts', () => {
-  const unfilteredConfigRules = plugin.configs.stylistic[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.stylistic[2]?.rules;
 
   it('contains all stylistic rules, excluding deprecated or type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -275,7 +277,7 @@ describe('stylistic.ts', () => {
 });
 
 describe('stylistic-type-checked.ts', () => {
-  const unfilteredConfigRules = plugin.configs.stylisticTypeChecked[2]?.rules;
+  const unfilteredConfigRules = tseslint.configs.stylisticTypeChecked[2]?.rules;
   const configRules = filterRules(unfilteredConfigRules);
   // note: include deprecated rules so that the config doesn't change between major bumps
   const ruleConfigs = filterAndMapRuleConfigs({
@@ -293,7 +295,7 @@ describe('stylistic-type-checked.ts', () => {
 
 describe('stylistic-type-checked-only.ts', () => {
   const unfilteredConfigRules =
-    plugin.configs.stylisticTypeCheckedOnly[2]?.rules;
+    tseslint.configs.stylisticTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked stylistic rules', () => {
     const configRules = filterRules(unfilteredConfigRules);

From 1bcab8a5caddc4f51ccef6e7a181f2feef5b6b36 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Wed, 7 May 2025 18:33:15 -0600
Subject: [PATCH 03/15] lintfix

---
 packages/typescript-eslint/tests/defineConfig-interop.test.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test.ts b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
index e35c8723e697..517bd47aea0d 100644
--- a/packages/typescript-eslint/tests/defineConfig-interop.test.ts
+++ b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
@@ -1,4 +1,5 @@
 import { defineConfig } from 'eslint/config';
+
 import * as tseslint from '../src/index';
 
 describe('tseslint.config() should be replaceable with defineConfig()', () => {

From 54341e091d54f388f510ae4b6d78551f390d6c5f Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Wed, 7 May 2025 18:36:38 -0600
Subject: [PATCH 04/15] revert unrelated change

---
 .../typescript-eslint/tests/configs.test.ts   | 26 +++++++++----------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/packages/typescript-eslint/tests/configs.test.ts b/packages/typescript-eslint/tests/configs.test.ts
index 3be135ea1e57..742178196c81 100644
--- a/packages/typescript-eslint/tests/configs.test.ts
+++ b/packages/typescript-eslint/tests/configs.test.ts
@@ -5,7 +5,7 @@ import type {
 
 import rules from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/rules';
 
-import tseslint from '../src/index';
+import plugin from '../src/index';
 
 const RULE_NAME_PREFIX = '@typescript-eslint/';
 const EXTENSION_RULES = Object.entries(rules)
@@ -107,7 +107,7 @@ function itHasBaseRulesOverriden(
 }
 
 describe('all.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.all[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.all[2]?.rules;
 
   it('contains all of the rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -125,7 +125,7 @@ describe('all.ts', () => {
 });
 
 describe('disable-type-checked.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.disableTypeChecked.rules;
+  const unfilteredConfigRules = plugin.configs.disableTypeChecked.rules;
 
   it('disables all type checked rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -141,7 +141,7 @@ describe('disable-type-checked.ts', () => {
 });
 
 describe('recommended.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.recommended[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.recommended[2]?.rules;
 
   it('contains all recommended rules, excluding type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -160,8 +160,7 @@ describe('recommended.ts', () => {
 });
 
 describe('recommended-type-checked.ts', () => {
-  const unfilteredConfigRules =
-    tseslint.configs.recommendedTypeChecked[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.recommendedTypeChecked[2]?.rules;
 
   it('contains all recommended rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -180,7 +179,7 @@ describe('recommended-type-checked.ts', () => {
 
 describe('recommended-type-checked-only.ts', () => {
   const unfilteredConfigRules =
-    tseslint.configs.recommendedTypeCheckedOnly[2]?.rules;
+    plugin.configs.recommendedTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked recommended rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -199,7 +198,7 @@ describe('recommended-type-checked-only.ts', () => {
 });
 
 describe('strict.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.strict[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.strict[2]?.rules;
 
   it('contains all strict rules, excluding type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -219,7 +218,7 @@ describe('strict.ts', () => {
 });
 
 describe('strict-type-checked.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.strictTypeChecked[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.strictTypeChecked[2]?.rules;
 
   it('contains all strict rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -237,8 +236,7 @@ describe('strict-type-checked.ts', () => {
 });
 
 describe('strict-type-checked-only.ts', () => {
-  const unfilteredConfigRules =
-    tseslint.configs.strictTypeCheckedOnly[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.strictTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked strict rules', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -258,7 +256,7 @@ describe('strict-type-checked-only.ts', () => {
 });
 
 describe('stylistic.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.stylistic[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.stylistic[2]?.rules;
 
   it('contains all stylistic rules, excluding deprecated or type checked ones', () => {
     const configRules = filterRules(unfilteredConfigRules);
@@ -277,7 +275,7 @@ describe('stylistic.ts', () => {
 });
 
 describe('stylistic-type-checked.ts', () => {
-  const unfilteredConfigRules = tseslint.configs.stylisticTypeChecked[2]?.rules;
+  const unfilteredConfigRules = plugin.configs.stylisticTypeChecked[2]?.rules;
   const configRules = filterRules(unfilteredConfigRules);
   // note: include deprecated rules so that the config doesn't change between major bumps
   const ruleConfigs = filterAndMapRuleConfigs({
@@ -295,7 +293,7 @@ describe('stylistic-type-checked.ts', () => {
 
 describe('stylistic-type-checked-only.ts', () => {
   const unfilteredConfigRules =
-    tseslint.configs.stylisticTypeCheckedOnly[2]?.rules;
+    plugin.configs.stylisticTypeCheckedOnly[2]?.rules;
 
   it('contains only type-checked stylistic rules', () => {
     const configRules = filterRules(unfilteredConfigRules);

From 29e647d1cfed2a9667bf779e6455ed509eb3f4d4 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Wed, 7 May 2025 18:39:15 -0600
Subject: [PATCH 05/15] dep

---
 packages/typescript-eslint/package.json | 1 +
 yarn.lock                               | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/typescript-eslint/package.json b/packages/typescript-eslint/package.json
index e9cd6e862734..f67c5081cbb7 100644
--- a/packages/typescript-eslint/package.json
+++ b/packages/typescript-eslint/package.json
@@ -51,6 +51,7 @@
     "check-types": "npx nx typecheck"
   },
   "dependencies": {
+    "@eslint/config-helpers": "^0.2",
     "@typescript-eslint/eslint-plugin": "8.32.0",
     "@typescript-eslint/parser": "8.32.0",
     "@typescript-eslint/utils": "8.32.0"
diff --git a/yarn.lock b/yarn.lock
index 1bbd20ef8cae..51652e1b89a2 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3263,7 +3263,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@eslint/config-helpers@npm:^0.2.1":
+"@eslint/config-helpers@npm:^0.2, @eslint/config-helpers@npm:^0.2.1":
   version: 0.2.2
   resolution: "@eslint/config-helpers@npm:0.2.2"
   checksum: 8a4091a2c8af5366513647ccad720f184c1b723f04c086755797a3a5cac69dc9013bc8a75453d9fc188fc4364460f0eae9f1584b77b28082e0d26bf48356ae8f
@@ -18701,6 +18701,7 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "typescript-eslint@workspace:packages/typescript-eslint"
   dependencies:
+    "@eslint/config-helpers": ^0.2
     "@typescript-eslint/eslint-plugin": 8.32.0
     "@typescript-eslint/parser": 8.32.0
     "@typescript-eslint/utils": 8.32.0

From ff95b9a493cc90dc18962ac67d7a5d93cad20219 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Fri, 9 May 2025 14:30:10 -0700
Subject: [PATCH 06/15] some feedback

---
 packages/typescript-eslint/src/index.ts       | 75 +++++++++----------
 .../tests/defineConfig-interop.test.ts        |  8 ++
 2 files changed, 45 insertions(+), 38 deletions(-)

diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 6f94a309eed0..e5c78408abf6 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -8,7 +8,15 @@ import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw
 
 import { config } from './config-helper';
 
-export const parser: TSESLint.FlatConfig.Parser = rawPlugin.parser;
+// Couldn't find a way to directly get to the eslint Linter.Parser type...
+// We don't want to get it directly from eslint, since the supported eslint versions include eslint 8.x as well.
+// '@eslint/config-helpers' doesn't re-export the Linter namespace, just some of its contents.
+// So this is a bit yucky but it should get the type we want.
+type ESLintParserType = NonNullable<
+  NonNullable<eslintConfigHelpers.Config['languageOptions']>['parser']
+>;
+
+export const parser = rawPlugin.parser as ESLintParserType;
 
 /*
 we could build a plugin object here without the `configs` key - but if we do
@@ -35,28 +43,25 @@ from using them.
 */
 export const plugin = pluginBase as unknown as eslintConfigHelpers.Plugin;
 
-/* eslint-disable @typescript-eslint/no-unnecessary-type-assertion -- These "unnecessary" assertions work around "requires explicit type annotation" errors. */
 export const configs = {
   /**
    * Enables each the rules provided as a part of typescript-eslint. Note that many rules are not applicable in all codebases, or are meant to be configured.
    * @see {@link https://typescript-eslint.io/users/configs#all}
    */
-  all: rawPlugin.flatConfigs['flat/all'] as eslintConfigHelpers.Config[],
+  all: rawPlugin.flatConfigs['flat/all'],
 
   /**
    * A minimal ruleset that sets only the required parser and plugin options needed to run typescript-eslint.
    * We don't recommend using this directly; instead, extend from an earlier recommended rule.
    * @see {@link https://typescript-eslint.io/users/configs#base}
    */
-  base: rawPlugin.flatConfigs['flat/base'] as eslintConfigHelpers.Config,
+  base: rawPlugin.flatConfigs['flat/base'],
 
   /**
    * A utility ruleset that will disable type-aware linting and all type-aware rules available in our project.
    * @see {@link https://typescript-eslint.io/users/configs#disable-type-checked}
    */
-  disableTypeChecked: rawPlugin.flatConfigs[
-    'flat/disable-type-checked'
-  ] as eslintConfigHelpers.Config,
+  disableTypeChecked: rawPlugin.flatConfigs['flat/disable-type-checked'],
 
   /**
    * This is a compatibility ruleset that:
@@ -64,82 +69,76 @@ export const configs = {
    * - enables rules that make sense due to TS's typechecking / transpilation.
    * @see {@link https://typescript-eslint.io/users/configs/#eslint-recommended}
    */
-  eslintRecommended: rawPlugin.flatConfigs[
-    'flat/eslint-recommended'
-  ] as eslintConfigHelpers.Config,
+  eslintRecommended: rawPlugin.flatConfigs['flat/eslint-recommended'],
 
   /**
    * Recommended rules for code correctness that you can drop in without additional configuration.
    * @see {@link https://typescript-eslint.io/users/configs#recommended}
    */
-  recommended: rawPlugin.flatConfigs[
-    'flat/recommended'
-  ] as eslintConfigHelpers.Config[],
+  recommended: rawPlugin.flatConfigs['flat/recommended'],
 
   /**
    * Contains all of `recommended` along with additional recommended rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked}
    */
-  recommendedTypeChecked: rawPlugin.flatConfigs[
-    'flat/recommended-type-checked'
-  ] as eslintConfigHelpers.Config[],
+  recommendedTypeChecked:
+    rawPlugin.flatConfigs['flat/recommended-type-checked'],
 
   /**
    * A version of `recommended` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#recommended-type-checked-only}
    */
-  recommendedTypeCheckedOnly: rawPlugin.flatConfigs[
-    'flat/recommended-type-checked-only'
-  ] as eslintConfigHelpers.Config[],
+  recommendedTypeCheckedOnly:
+    rawPlugin.flatConfigs['flat/recommended-type-checked-only'],
 
   /**
    * Contains all of `recommended`, as well as additional strict rules that can also catch bugs.
    * @see {@link https://typescript-eslint.io/users/configs#strict}
    */
-  strict: rawPlugin.flatConfigs['flat/strict'] as eslintConfigHelpers.Config[],
+  strict: rawPlugin.flatConfigs['flat/strict'],
 
   /**
    * Contains all of `recommended`, `recommended-type-checked`, and `strict`, along with additional strict rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked}
    */
-  strictTypeChecked: rawPlugin.flatConfigs[
-    'flat/strict-type-checked'
-  ] as eslintConfigHelpers.Config[],
+  strictTypeChecked: rawPlugin.flatConfigs['flat/strict-type-checked'],
 
   /**
    * A version of `strict` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#strict-type-checked-only}
    */
-  strictTypeCheckedOnly: rawPlugin.flatConfigs[
-    'flat/strict-type-checked-only'
-  ] as eslintConfigHelpers.Config[],
+  strictTypeCheckedOnly: rawPlugin.flatConfigs['flat/strict-type-checked-only'],
 
   /**
    * Rules considered to be best practice for modern TypeScript codebases, but that do not impact program logic.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic}
    */
-  stylistic: rawPlugin.flatConfigs[
-    'flat/stylistic'
-  ] as eslintConfigHelpers.Config[],
+  stylistic: rawPlugin.flatConfigs['flat/stylistic'],
 
   /**
    * Contains all of `stylistic`, along with additional stylistic rules that require type information.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked}
    */
-  stylisticTypeChecked: rawPlugin.flatConfigs[
-    'flat/stylistic-type-checked'
-  ] as eslintConfigHelpers.Config[],
+  stylisticTypeChecked: rawPlugin.flatConfigs['flat/stylistic-type-checked'],
 
   /**
    * A version of `stylistic` that only contains type-checked rules and disables of any corresponding core ESLint rules.
    * @see {@link https://typescript-eslint.io/users/configs#stylistic-type-checked-only}
    */
-  stylisticTypeCheckedOnly: rawPlugin.flatConfigs[
-    'flat/stylistic-type-checked-only'
-  ] as eslintConfigHelpers.Config[],
-};
-/* eslint-enable @typescript-eslint/no-unnecessary-type-assertion */
-
+  stylisticTypeCheckedOnly:
+    rawPlugin.flatConfigs['flat/stylistic-type-checked-only'],
+} satisfies Record<
+  string,
+  eslintConfigHelpers.Config | eslintConfigHelpers.Config[]
+>;
+
+/**
+ * The expected shape of the default export of an eslint flat config file.
+ *
+ * @deprecated ESLint core provides their own config types, and we now recommend using them instead.
+ * @see {@link https://github.com/typescript-eslint/typescript-eslint/issues/10899}
+ * @see {@link https://github.com/eslint/eslint/pull/19487}
+ */
 export type Config = TSESLint.FlatConfig.ConfigFile;
 
 /*
diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test.ts b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
index 517bd47aea0d..2092ca1a494a 100644
--- a/packages/typescript-eslint/tests/defineConfig-interop.test.ts
+++ b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
@@ -14,4 +14,12 @@ describe('tseslint.config() should be replaceable with defineConfig()', () => {
       },
     });
   });
+
+  it('should allow manual assignment of the parser', () => {
+    defineConfig({
+      languageOptions: {
+        parser: tseslint.parser,
+      },
+    });
+  });
 });

From 526480d84b8920c1ce4fd00a6637904deabbb30c Mon Sep 17 00:00:00 2001
From: Arya Emami <aryaemami59@yahoo.com>
Date: Fri, 9 May 2025 18:03:38 -0500
Subject: [PATCH 07/15] add type tests for `defineConfig`

---
 packages/typescript-eslint/project.json       |  3 +-
 .../tests/defineConfig-interop.test-d.ts      | 43 +++++++++++++++++++
 .../tests/defineConfig-interop.test.ts        | 25 -----------
 packages/typescript-eslint/vitest.config.mts  |  5 +++
 4 files changed, 50 insertions(+), 26 deletions(-)
 create mode 100644 packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
 delete mode 100644 packages/typescript-eslint/tests/defineConfig-interop.test.ts

diff --git a/packages/typescript-eslint/project.json b/packages/typescript-eslint/project.json
index 121581ef2b13..1203fe9cd575 100644
--- a/packages/typescript-eslint/project.json
+++ b/packages/typescript-eslint/project.json
@@ -10,7 +10,8 @@
       "outputs": ["{options.outputFile}"]
     },
     "test": {
-      "executor": "@nx/vite:test"
+      "executor": "@nx/vite:test",
+      "dependsOn": ["^build", "typecheck"]
     }
   }
 }
diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts b/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
new file mode 100644
index 000000000000..66aed7d91a4e
--- /dev/null
+++ b/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
@@ -0,0 +1,43 @@
+import { defineConfig } from 'eslint/config';
+
+import type { Linter } from 'eslint';
+
+import * as tseslint from '../src/index.js';
+
+describe('tseslint.config() should be replaceable with defineConfig()', () => {
+  it('should work with recommended setup', () => {
+    const eslintConfig = defineConfig(tseslint.configs.recommended);
+
+    const tseslintConfig = tseslint.config(tseslint.configs.recommended);
+
+    expectTypeOf(defineConfig)
+      .toBeCallableWith(tseslint.configs.recommended)
+      .returns.items.toExtend<(typeof tseslintConfig)[number]>();
+
+    expectTypeOf(eslintConfig).toExtend<typeof tseslintConfig>();
+
+    expectTypeOf(eslintConfig).items.toExtend<
+      (typeof tseslintConfig)[number]
+    >();
+  });
+
+  it('should allow manual assignment of the plugin', () => {
+    expectTypeOf(defineConfig)
+      .toBeCallableWith({
+        plugins: {
+          ts: tseslint.plugin,
+        },
+      })
+      .returns.items.toEqualTypeOf<Linter.Config>();
+  });
+
+  it('should allow manual assignment of the parser', () => {
+    expectTypeOf(defineConfig)
+      .toBeCallableWith({
+        languageOptions: {
+          parser: tseslint.parser,
+        },
+      })
+      .returns.items.toEqualTypeOf<Linter.Config>();
+  });
+});
diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test.ts b/packages/typescript-eslint/tests/defineConfig-interop.test.ts
deleted file mode 100644
index 2092ca1a494a..000000000000
--- a/packages/typescript-eslint/tests/defineConfig-interop.test.ts
+++ /dev/null
@@ -1,25 +0,0 @@
-import { defineConfig } from 'eslint/config';
-
-import * as tseslint from '../src/index';
-
-describe('tseslint.config() should be replaceable with defineConfig()', () => {
-  it('should work with recommended setup', () => {
-    defineConfig(tseslint.configs.recommended);
-  });
-
-  it('should allow manual assignment of the plugin', () => {
-    defineConfig({
-      plugins: {
-        ts: tseslint.plugin,
-      },
-    });
-  });
-
-  it('should allow manual assignment of the parser', () => {
-    defineConfig({
-      languageOptions: {
-        parser: tseslint.parser,
-      },
-    });
-  });
-});
diff --git a/packages/typescript-eslint/vitest.config.mts b/packages/typescript-eslint/vitest.config.mts
index 7d1cc31b83d7..29604585074c 100644
--- a/packages/typescript-eslint/vitest.config.mts
+++ b/packages/typescript-eslint/vitest.config.mts
@@ -14,6 +14,11 @@ const vitestConfig = mergeConfig(
       dir: path.join(import.meta.dirname, 'tests'),
       name: packageJson.name,
       root: import.meta.dirname,
+
+      typecheck: {
+        enabled: true,
+        tsconfig: path.join(import.meta.dirname, 'tsconfig.spec.json'),
+      },
     },
   }),
 );

From 46e2e7e81b00ecab352f21ad7b54ef7214ced773 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 12 May 2025 15:19:44 -0700
Subject: [PATCH 08/15] tweaks

---
 .../tests/defineConfig-interop.test-d.ts      | 43 ++++++-------------
 1 file changed, 14 insertions(+), 29 deletions(-)

diff --git a/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts b/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
index 66aed7d91a4e..b9302a17de0d 100644
--- a/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
+++ b/packages/typescript-eslint/tests/defineConfig-interop.test-d.ts
@@ -1,43 +1,28 @@
 import { defineConfig } from 'eslint/config';
 
-import type { Linter } from 'eslint';
-
 import * as tseslint from '../src/index.js';
 
+// Type tests to ensure that migration from `tseslint.config()` -> `defineConfig()`
+// doesn't introduce type errors for the user. We don't care about the
+// `defineConfig()` -> `tseslint.config()` direction.
 describe('tseslint.config() should be replaceable with defineConfig()', () => {
   it('should work with recommended setup', () => {
-    const eslintConfig = defineConfig(tseslint.configs.recommended);
-
-    const tseslintConfig = tseslint.config(tseslint.configs.recommended);
-
-    expectTypeOf(defineConfig)
-      .toBeCallableWith(tseslint.configs.recommended)
-      .returns.items.toExtend<(typeof tseslintConfig)[number]>();
-
-    expectTypeOf(eslintConfig).toExtend<typeof tseslintConfig>();
-
-    expectTypeOf(eslintConfig).items.toExtend<
-      (typeof tseslintConfig)[number]
-    >();
+    expectTypeOf(defineConfig).toBeCallableWith(tseslint.configs.recommended);
   });
 
   it('should allow manual assignment of the plugin', () => {
-    expectTypeOf(defineConfig)
-      .toBeCallableWith({
-        plugins: {
-          ts: tseslint.plugin,
-        },
-      })
-      .returns.items.toEqualTypeOf<Linter.Config>();
+    expectTypeOf(defineConfig).toBeCallableWith({
+      plugins: {
+        ts: tseslint.plugin,
+      },
+    });
   });
 
   it('should allow manual assignment of the parser', () => {
-    expectTypeOf(defineConfig)
-      .toBeCallableWith({
-        languageOptions: {
-          parser: tseslint.parser,
-        },
-      })
-      .returns.items.toEqualTypeOf<Linter.Config>();
+    expectTypeOf(defineConfig).toBeCallableWith({
+      languageOptions: {
+        parser: tseslint.parser,
+      },
+    });
   });
 });

From 9bb9f95c55ab28281b5bd8c197de52c8bde2639f Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Fri, 16 May 2025 11:43:36 -0600
Subject: [PATCH 09/15] undeclared dep

---
 packages/eslint-plugin/package.json | 1 +
 yarn.lock                           | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/eslint-plugin/package.json b/packages/eslint-plugin/package.json
index c27d09067eab..21d7789b4170 100644
--- a/packages/eslint-plugin/package.json
+++ b/packages/eslint-plugin/package.json
@@ -61,6 +61,7 @@
   },
   "dependencies": {
     "@eslint-community/regexpp": "^4.10.0",
+    "@eslint/config-helpers": "^0.2",
     "@typescript-eslint/scope-manager": "8.32.1",
     "@typescript-eslint/type-utils": "8.32.1",
     "@typescript-eslint/utils": "8.32.1",
diff --git a/yarn.lock b/yarn.lock
index 661ea94c0dca..c0363d45f8a3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5528,6 +5528,7 @@ __metadata:
   resolution: "@typescript-eslint/eslint-plugin@workspace:packages/eslint-plugin"
   dependencies:
     "@eslint-community/regexpp": ^4.10.0
+    "@eslint/config-helpers": ^0.2
     "@types/mdast": ^4.0.3
     "@types/natural-compare": "*"
     "@typescript-eslint/rule-schema-to-typescript-types": 8.32.1

From 6730308f2600c02cf93eb067ba0a4012dc7ee8c2 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Fri, 16 May 2025 11:55:52 -0600
Subject: [PATCH 10/15] lintfix

---
 packages/typescript-eslint/src/index.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index e5c78408abf6..5a2b930d133f 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -1,5 +1,4 @@
 import type * as eslintConfigHelpers from '@eslint/config-helpers';
-
 // see the comment in config-helper.ts for why this doesn't use /ts-eslint
 import type { TSESLint } from '@typescript-eslint/utils';
 

From 917613d786eff22586c3cbf55330ecfdefe369e2 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 2 Jun 2025 12:25:26 -0600
Subject: [PATCH 11/15] remove dependency on eslint types

---
 packages/eslint-plugin/package.json       |  1 -
 packages/eslint-plugin/raw-plugin.d.ts    | 42 +++++++++++++++--------
 packages/typescript-eslint/package.json   |  2 +-
 packages/utils/src/ts-eslint/Parser.ts    |  2 +-
 packages/visitor-keys/src/visitor-keys.ts |  7 ++--
 yarn.lock                                 |  1 -
 6 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/packages/eslint-plugin/package.json b/packages/eslint-plugin/package.json
index 21d7789b4170..c27d09067eab 100644
--- a/packages/eslint-plugin/package.json
+++ b/packages/eslint-plugin/package.json
@@ -61,7 +61,6 @@
   },
   "dependencies": {
     "@eslint-community/regexpp": "^4.10.0",
-    "@eslint/config-helpers": "^0.2",
     "@typescript-eslint/scope-manager": "8.32.1",
     "@typescript-eslint/type-utils": "8.32.1",
     "@typescript-eslint/utils": "8.32.1",
diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index 5095ecaf23f1..6bec8524e55a 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -1,23 +1,37 @@
-import type * as eslintConfigHelpers from '@eslint/config-helpers';
 import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
 
+import type * as parserBase from '@typescript-eslint/parser';
+
 import type plugin from './index';
 
+type TSESLintConfig = {
+  name?: string;
+  rules?: Record<string, any>;
+  languageOptions?: {
+    sourceType?: 'module';
+    parser?: {
+      meta: typeof parserBase.meta;
+      parseForESLint: typeof parserBase.parseForESLint;
+    };
+    parserOptions?: Record<string, unknown>;
+  };
+};
+
 declare const cjsExport: {
   flatConfigs: {
-    'flat/all': eslintConfigHelpers.Config[];
-    'flat/base': eslintConfigHelpers.Config;
-    'flat/disable-type-checked': eslintConfigHelpers.Config;
-    'flat/eslint-recommended': eslintConfigHelpers.Config;
-    'flat/recommended': eslintConfigHelpers.Config[];
-    'flat/recommended-type-checked': eslintConfigHelpers.Config[];
-    'flat/recommended-type-checked-only': eslintConfigHelpers.Config[];
-    'flat/strict': eslintConfigHelpers.Config[];
-    'flat/strict-type-checked': eslintConfigHelpers.Config[];
-    'flat/strict-type-checked-only': eslintConfigHelpers.Config[];
-    'flat/stylistic': eslintConfigHelpers.Config[];
-    'flat/stylistic-type-checked': eslintConfigHelpers.Config[];
-    'flat/stylistic-type-checked-only': eslintConfigHelpers.Config[];
+    'flat/all': TSESLintConfig[];
+    'flat/base': TSESLintConfig;
+    'flat/disable-type-checked': TSESLintConfig;
+    'flat/eslint-recommended': TSESLintConfig;
+    'flat/recommended': TSESLintConfig[];
+    'flat/recommended-type-checked': TSESLintConfig[];
+    'flat/recommended-type-checked-only': TSESLintConfig[];
+    'flat/strict': TSESLintConfig[];
+    'flat/strict-type-checked': TSESLintConfig[];
+    'flat/strict-type-checked-only': TSESLintConfig[];
+    'flat/stylistic': TSESLintConfig[];
+    'flat/stylistic-type-checked': TSESLintConfig[];
+    'flat/stylistic-type-checked-only': TSESLintConfig[];
   };
   parser: FlatConfig.Parser;
   plugin: typeof plugin;
diff --git a/packages/typescript-eslint/package.json b/packages/typescript-eslint/package.json
index d568ad92d08c..5d167792ec89 100644
--- a/packages/typescript-eslint/package.json
+++ b/packages/typescript-eslint/package.json
@@ -50,7 +50,6 @@
     "check-types": "npx nx typecheck"
   },
   "dependencies": {
-    "@eslint/config-helpers": "^0.2",
     "@typescript-eslint/eslint-plugin": "8.32.1",
     "@typescript-eslint/parser": "8.32.1",
     "@typescript-eslint/utils": "8.32.1"
@@ -60,6 +59,7 @@
     "typescript": ">=4.8.4 <5.9.0"
   },
   "devDependencies": {
+    "@eslint/config-helpers": "^0.2",
     "@vitest/coverage-v8": "^3.1.3",
     "prettier": "^3.2.5",
     "rimraf": "*",
diff --git a/packages/utils/src/ts-eslint/Parser.ts b/packages/utils/src/ts-eslint/Parser.ts
index ad9f5763054f..0b1017fba37a 100644
--- a/packages/utils/src/ts-eslint/Parser.ts
+++ b/packages/utils/src/ts-eslint/Parser.ts
@@ -101,6 +101,6 @@ export namespace Parser {
 
   // eslint-disable-next-line @typescript-eslint/consistent-indexed-object-style
   export interface VisitorKeys {
-    [nodeType: string]: readonly string[];
+    [nodeType: string]: string[];
   }
 }
diff --git a/packages/visitor-keys/src/visitor-keys.ts b/packages/visitor-keys/src/visitor-keys.ts
index 283d2f36e389..64e18f2f2911 100644
--- a/packages/visitor-keys/src/visitor-keys.ts
+++ b/packages/visitor-keys/src/visitor-keys.ts
@@ -2,7 +2,7 @@ import type { AST_NODE_TYPES, TSESTree } from '@typescript-eslint/types';
 
 import * as eslintVisitorKeys from 'eslint-visitor-keys';
 
-export type VisitorKeys = Record<string, readonly string[] | undefined>;
+export type VisitorKeys = Record<string, string[]>;
 
 type GetNodeTypeKeys<T extends AST_NODE_TYPES> = Exclude<
   keyof Extract<TSESTree.Node, { type: T }>,
@@ -268,5 +268,6 @@ const additionalKeys: AdditionalKeys = {
   TSVoidKeyword: [],
 };
 
-export const visitorKeys: VisitorKeys =
-  eslintVisitorKeys.unionWith(additionalKeys);
+export const visitorKeys: VisitorKeys = eslintVisitorKeys.unionWith(
+  additionalKeys,
+) satisfies Record<string, readonly string[]> as Record<string, string[]>;
diff --git a/yarn.lock b/yarn.lock
index c0363d45f8a3..661ea94c0dca 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5528,7 +5528,6 @@ __metadata:
   resolution: "@typescript-eslint/eslint-plugin@workspace:packages/eslint-plugin"
   dependencies:
     "@eslint-community/regexpp": ^4.10.0
-    "@eslint/config-helpers": ^0.2
     "@types/mdast": ^4.0.3
     "@types/natural-compare": "*"
     "@typescript-eslint/rule-schema-to-typescript-types": 8.32.1

From 82aee0687e8e849fa2948af55f9980c18075b399 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 2 Jun 2025 12:35:34 -0600
Subject: [PATCH 12/15] simplify

---
 packages/eslint-plugin/raw-plugin.d.ts  | 12 +++++++-----
 packages/typescript-eslint/src/index.ts |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index 6bec8524e55a..b1156f5a87d5 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -4,15 +4,17 @@ import type * as parserBase from '@typescript-eslint/parser';
 
 import type plugin from './index';
 
+type TSESLintParser = {
+  meta: typeof parserBase.meta;
+  parseForESLint: typeof parserBase.parseForESLint;
+};
+
 type TSESLintConfig = {
   name?: string;
   rules?: Record<string, any>;
   languageOptions?: {
     sourceType?: 'module';
-    parser?: {
-      meta: typeof parserBase.meta;
-      parseForESLint: typeof parserBase.parseForESLint;
-    };
+    parser?: TSESLintParser;
     parserOptions?: Record<string, unknown>;
   };
 };
@@ -33,7 +35,7 @@ declare const cjsExport: {
     'flat/stylistic-type-checked': TSESLintConfig[];
     'flat/stylistic-type-checked-only': TSESLintConfig[];
   };
-  parser: FlatConfig.Parser;
+  parser: TSESLintParser;
   plugin: typeof plugin;
 };
 
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 5a2b930d133f..6e1631e5eb8a 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -15,7 +15,7 @@ type ESLintParserType = NonNullable<
   NonNullable<eslintConfigHelpers.Config['languageOptions']>['parser']
 >;
 
-export const parser = rawPlugin.parser as ESLintParserType;
+export const parser = rawPlugin.parser satisfies ESLintParserType;
 
 /*
 we could build a plugin object here without the `configs` key - but if we do

From 493bddebcae2a69a8add25f4791bb23a3d1bdbe4 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 2 Jun 2025 13:13:15 -0600
Subject: [PATCH 13/15] fix the plugin type

---
 packages/eslint-plugin/index.d.ts       |  8 +++-----
 packages/eslint-plugin/raw-plugin.d.ts  | 22 +++++++++++++++++++---
 packages/typescript-eslint/src/index.ts |  7 ++++---
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/packages/eslint-plugin/index.d.ts b/packages/eslint-plugin/index.d.ts
index 756a025eb97d..5d22546921aa 100644
--- a/packages/eslint-plugin/index.d.ts
+++ b/packages/eslint-plugin/index.d.ts
@@ -4,10 +4,8 @@ import type {
 } from '@typescript-eslint/utils/ts-eslint';
 
 import type rules from './rules';
+import { TSESLintPlugin } from './raw-plugin';
+
+declare const cjsExport: TSESLintPlugin;
 
-declare const cjsExport: {
-  configs: Record<string, ClassicConfig.Config>;
-  meta: FlatConfig.PluginMeta;
-  rules: typeof rules;
-};
 export = cjsExport;
diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index b1156f5a87d5..4db562a4aa4d 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -2,21 +2,37 @@ import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
 
 import type * as parserBase from '@typescript-eslint/parser';
 
-import type plugin from './index';
+import type * as parserBase from '@typescript-eslint/parser';
+import { Linter } from '@typescript-eslint/utils/ts-eslint';
 
-type TSESLintParser = {
+export type TSESLintParser = {
   meta: typeof parserBase.meta;
   parseForESLint: typeof parserBase.parseForESLint;
 };
 
-type TSESLintConfig = {
+export type TSESLintConfig = {
   name?: string;
   rules?: Record<string, any>;
+  files?: string[];
   languageOptions?: {
     sourceType?: 'module';
     parser?: TSESLintParser;
     parserOptions?: Record<string, unknown>;
   };
+
+  // causes type errors :shrug:
+  // plugins?: {
+  //   '@typescript-eslint': TSESLintPlugin;
+  // };
+};
+
+export type TSESLintPlugin = {
+  configs: Record<string, TSESLintConfig | TSESLintConfig[]>;
+  meta: {
+    name: string;
+    version: string;
+  };
+  rules: Record<string, Linter.PluginRules>;
 };
 
 declare const cjsExport: {
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 6e1631e5eb8a..85578bd37e79 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -2,8 +2,9 @@ import type * as eslintConfigHelpers from '@eslint/config-helpers';
 // see the comment in config-helper.ts for why this doesn't use /ts-eslint
 import type { TSESLint } from '@typescript-eslint/utils';
 
-import pluginBase from '@typescript-eslint/eslint-plugin';
-import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw-plugin';
+import rawPlugin, {
+  TSESLintConfig,
+} from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw-plugin';
 
 import { config } from './config-helper';
 
@@ -40,7 +41,7 @@ use our new package); however legacy configs consumed via `@eslint/eslintrc`
 would never be able to satisfy this constraint and thus users would be blocked
 from using them.
 */
-export const plugin = pluginBase as unknown as eslintConfigHelpers.Plugin;
+export const plugin = rawPlugin.plugin satisfies eslintConfigHelpers.Plugin;
 
 export const configs = {
   /**

From 08d57bac3fb3f067249821a80e2871b788a98107 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 2 Jun 2025 13:14:45 -0600
Subject: [PATCH 14/15] whoops

---
 packages/eslint-plugin/raw-plugin.d.ts | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index 4db562a4aa4d..70c740960e73 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -1,18 +1,14 @@
-import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';
-
-import type * as parserBase from '@typescript-eslint/parser';
-
 import type * as parserBase from '@typescript-eslint/parser';
-import { Linter } from '@typescript-eslint/utils/ts-eslint';
+import type { Linter } from '@typescript-eslint/utils/ts-eslint';
 
-export type TSESLintParser = {
+export interface TSESLintParser {
   meta: typeof parserBase.meta;
   parseForESLint: typeof parserBase.parseForESLint;
-};
+}
 
-export type TSESLintConfig = {
+export interface TSESLintConfig {
   name?: string;
-  rules?: Record<string, any>;
+  rules?: Record<string, unknown>;
   files?: string[];
   languageOptions?: {
     sourceType?: 'module';
@@ -24,16 +20,16 @@ export type TSESLintConfig = {
   // plugins?: {
   //   '@typescript-eslint': TSESLintPlugin;
   // };
-};
+}
 
-export type TSESLintPlugin = {
+export interface TSESLintPlugin {
   configs: Record<string, TSESLintConfig | TSESLintConfig[]>;
   meta: {
     name: string;
     version: string;
   };
   rules: Record<string, Linter.PluginRules>;
-};
+}
 
 declare const cjsExport: {
   flatConfigs: {

From 893c9594576fcbc467fbcd14f29c1c7b4c2652d5 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <53019676+kirkwaiblinger@users.noreply.github.com>
Date: Mon, 2 Jun 2025 13:34:48 -0600
Subject: [PATCH 15/15] plugin

---
 packages/eslint-plugin/raw-plugin.d.ts  | 6 +++---
 packages/typescript-eslint/src/index.ts | 4 +---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/packages/eslint-plugin/raw-plugin.d.ts b/packages/eslint-plugin/raw-plugin.d.ts
index 70c740960e73..e60f412fc4f4 100644
--- a/packages/eslint-plugin/raw-plugin.d.ts
+++ b/packages/eslint-plugin/raw-plugin.d.ts
@@ -8,7 +8,7 @@ export interface TSESLintParser {
 
 export interface TSESLintConfig {
   name?: string;
-  rules?: Record<string, unknown>;
+  rules?: Record<string, ['error' | 'off', ...unknown[]]>;
   files?: string[];
   languageOptions?: {
     sourceType?: 'module';
@@ -28,7 +28,7 @@ export interface TSESLintPlugin {
     name: string;
     version: string;
   };
-  rules: Record<string, Linter.PluginRules>;
+  rules: Linter.PluginRules;
 }
 
 declare const cjsExport: {
@@ -48,7 +48,7 @@ declare const cjsExport: {
     'flat/stylistic-type-checked-only': TSESLintConfig[];
   };
   parser: TSESLintParser;
-  plugin: typeof plugin;
+  plugin: TSESLintPlugin;
 };
 
 export = cjsExport;
diff --git a/packages/typescript-eslint/src/index.ts b/packages/typescript-eslint/src/index.ts
index 85578bd37e79..833137ca9491 100644
--- a/packages/typescript-eslint/src/index.ts
+++ b/packages/typescript-eslint/src/index.ts
@@ -2,9 +2,7 @@ import type * as eslintConfigHelpers from '@eslint/config-helpers';
 // see the comment in config-helper.ts for why this doesn't use /ts-eslint
 import type { TSESLint } from '@typescript-eslint/utils';
 
-import rawPlugin, {
-  TSESLintConfig,
-} from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw-plugin';
+import rawPlugin from '@typescript-eslint/eslint-plugin/use-at-your-own-risk/raw-plugin';
 
 import { config } from './config-helper';