consistent-type-exports: offer the export * fix as a suggestion

`export *` loads the module; `export type *` is erased. The autofix
rewrote one into the other whenever a module exported only types, so a
module that registers something when loaded stopped being loaded (the
api typegen lost its Handlebars partial this way).

The report stays an error; the rewrite is now a suggestion, which --fix
does not apply. Named re-exports are unaffected: under
verbatimModuleSyntax their type-only form is already a compile error.

packages/dev/src/typeExports.spec.ts

@@ -0,0 +1,80 @@
+// Copyright 2017-2026 @pezkuwi/dev authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/// <reference types="@pezkuwi/dev-test/globals.d.ts" />
+
+import type { ESLint as ESLintType } from 'eslint';
+
+import tsPlugin from '@typescript-eslint/eslint-plugin';
+import tsParser from '@typescript-eslint/parser';
+import { ESLint } from 'eslint';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+
+// Loaded by path: the config directory is plain JavaScript outside this
+// package's TypeScript root.
+const WRAPPER = path.join(process.cwd(), 'packages/dev/config/eslint.typeExports.js');
+
+// only types, but loading it has an effect the importer relies on
+const TYPES = `export interface Partial { name: string }
+
+(globalThis as Record<string, unknown>)['registered'] = true;
+`;
+
+const SOURCE = `export * from './types.js';
+`;
+
+interface Result { fixed: string; messages: { fix: boolean; line: number; messageId: string; suggestions: number }[] }
+
+async function lint (plugin: ESLintType.Plugin): Promise<Result> {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'type-exports-'));
+
+  try {
+    fs.writeFileSync(path.join(dir, 'tsconfig.json'), JSON.stringify({ compilerOptions: { module: 'esnext', moduleResolution: 'bundler', strict: true, target: 'es2022' }, include: ['*.ts'] }));
+    fs.writeFileSync(path.join(dir, 'types.ts'), TYPES);
+    fs.writeFileSync(path.join(dir, 'index.ts'), SOURCE);
+
+    const options = (fix: boolean): ESLintType.Options => ({
+      cwd: dir,
+      fix,
+      overrideConfig: [{
+        files: ['**/*.ts'],
+        languageOptions: {
+          parser: tsParser,
+          parserOptions: { project: './tsconfig.json', tsconfigRootDir: dir }
+        },
+        plugins: { '@typescript-eslint': plugin },
+        rules: { '@typescript-eslint/consistent-type-exports': 'error' }
+      }],
+      overrideConfigFile: true
+    });
+    const [reported] = await new ESLint(options(false)).lintFiles(['index.ts']);
+    const [fixed] = await new ESLint(options(true)).lintFiles(['index.ts']);
+
+    return {
+      fixed: fixed.output ?? SOURCE,
+      messages: reported.messages.map(({ fix, line, messageId, suggestions }) => ({ fix: !!fix, line, messageId: messageId ?? '', suggestions: suggestions?.length ?? 0 }))
+    };
+  } finally {
+    fs.rmSync(dir, { force: true, recursive: true });
+  }
+}
+
+describe('withoutExportAllFix', (): void => {
+  it('keeps the report on a types-only export *, offers the change only as a suggestion', async (): Promise<void> => {
+    const { withoutExportAllFix } = await import(WRAPPER) as { withoutExportAllFix: (p: ESLintType.Plugin) => ESLintType.Plugin };
+
+    expect(await lint(withoutExportAllFix(tsPlugin as unknown as ESLintType.Plugin))).toEqual({
+      fixed: SOURCE,
+      messages: [{ fix: false, line: 1, messageId: 'typeOverValue', suggestions: 1 }]
+    });
+  });
+
+  it('is needed: the plugin as published rewrites it to export type *, which no longer loads the module', async (): Promise<void> => {
+    expect(await lint(tsPlugin as unknown as ESLintType.Plugin)).toEqual({
+      fixed: "export type * from './types.js';\n",
+      messages: [{ fix: true, line: 1, messageId: 'typeOverValue', suggestions: 0 }]
+    });
+  });
+});