fix: Type exported configs correctly (#95)

* Tighten types on exported configs

* Add tests

Author: porada

src/main.test.ts

@@ -1,5 +1,5 @@
 import {describe, it, expect} from 'vitest';
-import {ESLint, type Linter} from 'eslint';
+import {ESLint} from 'eslint';
 import * as jsoncParser from 'jsonc-eslint-parser';
 import json from '@eslint/json';
 import plugin from './main.js';
@@ -15,7 +15,7 @@ describe('main plugin', () => {
             parser: jsoncParser
           }
         },
-        plugin.configs!.recommended as Linter.Config
+        plugin.configs.recommended
       ]
     });
 
@@ -41,7 +41,7 @@ describe('main plugin', () => {
           },
           language: 'json/json'
         },
-        plugin.configs!.recommended as Linter.Config
+        plugin.configs.recommended
       ]
     });
 
@@ -55,4 +55,11 @@ describe('main plugin', () => {
     expect(results[0]!.messages).toHaveLength(0);
     expect(results[0]!.filePath).toContain('package.json');
   });
+
+  it('should export valid config types', () => {
+    expect(plugin.configs.recommended).toBeDefined();
+    expect(plugin.configs.modernization).toBeDefined();
+    expect(plugin.configs.moduleReplacements).toBeDefined();
+    expect(plugin.configs.performanceImprovements).toBeDefined();
+  });
 });

src/main.ts

@@ -29,7 +29,6 @@ const plugin: ESLint.Plugin = {
     name: 'e18e',
     namespace: 'e18e'
   },
-  configs: {},
   rules: {
     'prefer-array-at': preferArrayAt as never as Rule.RuleModule,
     'prefer-array-fill': preferArrayFill,
@@ -55,9 +54,15 @@ const plugin: ESLint.Plugin = {
   }
 };
 
-plugin.configs!.recommended = recommended(plugin);
-plugin.configs!.modernization = modernization(plugin);
-plugin.configs!.moduleReplacements = moduleReplacements(plugin);
-plugin.configs!.performanceImprovements = performanceImprovements(plugin);
+const configs = {
+  recommended: recommended(plugin),
+  modernization: modernization(plugin),
+  moduleReplacements: moduleReplacements(plugin),
+  performanceImprovements: performanceImprovements(plugin)
+} as const;
 
-export default plugin;
+plugin.configs = configs;
+
+export default plugin as Omit<ESLint.Plugin, 'configs'> & {
+  configs: typeof configs;
+};