From 2ada5aff1ef37bc260d7a0eaafe9ff04f8a08fe4 Mon Sep 17 00:00:00 2001
From: Gaon Kim <gaon.kim.dev@gmail.com>
Date: Mon, 7 Sep 2020 03:30:59 +0900
Subject: [PATCH] fix(eslint-plugin): [typedef] false positive for rest
 parameter with array destructuring (#2441)

---
 packages/eslint-plugin/src/rules/typedef.ts      |  6 ++++++
 .../eslint-plugin/tests/rules/typedef.test.ts    | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/packages/eslint-plugin/src/rules/typedef.ts b/packages/eslint-plugin/src/rules/typedef.ts
index 1d66cff4290..76640104022 100644
--- a/packages/eslint-plugin/src/rules/typedef.ts
+++ b/packages/eslint-plugin/src/rules/typedef.ts
@@ -141,6 +141,12 @@ export default util.createRule<[Options], MessageIds>({
 
     return {
       ArrayPattern(node): void {
+        if (
+          node.parent?.type === AST_NODE_TYPES.RestElement &&
+          node.parent.typeAnnotation
+        ) {
+          return;
+        }
         if (
           options[OptionKeys.ArrayDestructuring] &&
           !node.typeAnnotation &&
diff --git a/packages/eslint-plugin/tests/rules/typedef.test.ts b/packages/eslint-plugin/tests/rules/typedef.test.ts
index f3c24007716..09a4764a0ba 100644
--- a/packages/eslint-plugin/tests/rules/typedef.test.ts
+++ b/packages/eslint-plugin/tests/rules/typedef.test.ts
@@ -14,6 +14,22 @@ const ruleTester = new RuleTester({
 ruleTester.run('typedef', rule, {
   valid: [
     // Array destructuring
+    {
+      code: 'function foo(...[a]: string[]) {}',
+      options: [
+        {
+          arrayDestructuring: true,
+        },
+      ],
+    },
+    {
+      code: 'const foo = (...[a]: string[]) => {};',
+      options: [
+        {
+          arrayDestructuring: true,
+        },
+      ],
+    },
     {
       code: 'const [a]: [number] = [1];',
       options: [