feat(eslint-plugin): new import dedupe rule

packages/eslint-plugin-antfu/src/rules/import-dedupe.test.ts

@@ -0,0 +1,28 @@
+import { RuleTester } from '@typescript-eslint/utils/dist/ts-eslint'
+import { it } from 'vitest'
+import rule, { RULE_NAME } from './import-dedupe'
+
+const valids = [
+  'import { a } from \'foo\'',
+]
+const invalids = [
+  [
+    'import { a, b, a, a, c, a } from \'foo\'',
+    'import { a, b,   c,  } from \'foo\'',
+  ],
+]
+
+it('runs', () => {
+  const ruleTester: RuleTester = new RuleTester({
+    parser: require.resolve('@typescript-eslint/parser'),
+  })
+
+  ruleTester.run(RULE_NAME, rule, {
+    valid: valids,
+    invalid: invalids.map(i => ({
+      code: i[0],
+      output: i[1],
+      errors: [{ messageId: 'importDedupe' }, { messageId: 'importDedupe' }, { messageId: 'importDedupe' }],
+    })),
+  })
+})