fix(eslint-plugin): [typedef] false positive for rest parameter with array destructuring (typescript-eslint#2441)

gaonK · web-flow · commit 2ada5aff1ef3 · 2020-09-06T11:30:59.000-07:00
diff --git 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
@@ -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: [
