From 35aaeb7b77455629ed053643ba9e5e3eb6fd47cf Mon Sep 17 00:00:00 2001
From: lotmek <meklocdn@gmail.com>
Date: Mon, 14 Oct 2024 18:01:17 -0400
Subject: [PATCH] fix(rule-tester): allow custom filename outside directory

---
 packages/rule-tester/src/RuleTester.ts      | 10 ++++-
 packages/rule-tester/tests/filename.test.ts | 48 +++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 packages/rule-tester/tests/filename.test.ts

diff --git a/packages/rule-tester/src/RuleTester.ts b/packages/rule-tester/src/RuleTester.ts
index 9c04e0363c48..72b6b87a83cb 100644
--- a/packages/rule-tester/src/RuleTester.ts
+++ b/packages/rule-tester/src/RuleTester.ts
@@ -746,7 +746,15 @@ export class RuleTester extends TestFramework {
             ...configWithoutCustomKeys.linterOptions,
           },
         });
-        messages = this.#linter.verify(code, actualConfig, filename);
+        messages = this.#linter.verify(
+          code,
+          // ESLint uses an internal FlatConfigArray that extends @humanwhocodes/config-array.
+          Object.assign([], {
+            basePath: filename ? path.parse(filename).root : '',
+            getConfig: () => actualConfig,
+          }),
+          filename,
+        );
       } finally {
         SourceCode.prototype.applyInlineConfig = applyInlineConfig;
         SourceCode.prototype.applyLanguageOptions = applyLanguageOptions;
diff --git a/packages/rule-tester/tests/filename.test.ts b/packages/rule-tester/tests/filename.test.ts
new file mode 100644
index 000000000000..1c68f4ba196d
--- /dev/null
+++ b/packages/rule-tester/tests/filename.test.ts
@@ -0,0 +1,48 @@
+/* eslint-disable perfectionist/sort-objects */
+import { RuleTester } from '@typescript-eslint/rule-tester';
+import { ESLintUtils } from '@typescript-eslint/utils';
+
+const ruleTester = new RuleTester();
+
+const rule = ESLintUtils.RuleCreator.withoutDocs({
+  meta: {
+    docs: {
+      description: 'some description',
+    },
+    messages: {
+      foo: 'It works',
+    },
+    schema: [],
+    type: 'problem',
+  },
+  defaultOptions: [],
+  create: context => ({
+    Program(node): void {
+      context.report({ node, messageId: 'foo' });
+    },
+  }),
+});
+
+describe('rule tester filename', () => {
+  ruleTester.run('absolute path', rule, {
+    invalid: [
+      {
+        code: '_',
+        errors: [{ messageId: 'foo' }],
+        filename: '/an-absolute-path/foo.js',
+      },
+    ],
+    valid: [],
+  });
+
+  ruleTester.run('relative path', rule, {
+    invalid: [
+      {
+        code: '_',
+        errors: [{ messageId: 'foo' }],
+        filename: '../foo.js',
+      },
+    ],
+    valid: [],
+  });
+});