From 2c825fce0e797443fe9e5591d4aa0843c45959a8 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Fri, 29 Jul 2022 17:50:18 +0300
Subject: [PATCH] fix(49869): throw an error on optional binding pattern
 parameter in JavaScript

---
 src/compiler/checker.ts                          |  2 +-
 .../optionalBindingParameters3.errors.txt        | 16 ++++++++++++++++
 .../reference/optionalBindingParameters3.symbols | 13 +++++++++++++
 .../reference/optionalBindingParameters3.types   | 14 ++++++++++++++
 .../destructuring/optionalBindingParameters3.ts  | 14 ++++++++++++++
 5 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/optionalBindingParameters3.errors.txt
 create mode 100644 tests/baselines/reference/optionalBindingParameters3.symbols
 create mode 100644 tests/baselines/reference/optionalBindingParameters3.types
 create mode 100644 tests/cases/conformance/es6/destructuring/optionalBindingParameters3.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8556832569b76..a6f21c13f8251 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -35230,7 +35230,7 @@ namespace ts {
                     error(node.name, Diagnostics.constructor_cannot_be_used_as_a_parameter_property_name);
                 }
             }
-            if (node.questionToken && isBindingPattern(node.name) && (func as FunctionLikeDeclaration).body) {
+            if ((node.questionToken || isJSDocOptionalParameter(node)) && isBindingPattern(node.name) && (func as FunctionLikeDeclaration).body) {
                 error(node, Diagnostics.A_binding_pattern_parameter_cannot_be_optional_in_an_implementation_signature);
             }
             if (node.name && isIdentifier(node.name) && (node.name.escapedText === "this" || node.name.escapedText === "new")) {
diff --git a/tests/baselines/reference/optionalBindingParameters3.errors.txt b/tests/baselines/reference/optionalBindingParameters3.errors.txt
new file mode 100644
index 0000000000000..3e8e002141797
--- /dev/null
+++ b/tests/baselines/reference/optionalBindingParameters3.errors.txt
@@ -0,0 +1,16 @@
+/a.js(9,12): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+
+
+==== /a.js (1 errors) ====
+    /**
+     * @typedef Foo
+     * @property {string} a
+     */
+    
+    /**
+     * @param {Foo} [options]
+     */
+    function f({ a = "a" }) {}
+               ~~~~~~~~~~~
+!!! error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/optionalBindingParameters3.symbols b/tests/baselines/reference/optionalBindingParameters3.symbols
new file mode 100644
index 0000000000000..f8def8131fdaa
--- /dev/null
+++ b/tests/baselines/reference/optionalBindingParameters3.symbols
@@ -0,0 +1,13 @@
+=== /a.js ===
+/**
+ * @typedef Foo
+ * @property {string} a
+ */
+
+/**
+ * @param {Foo} [options]
+ */
+function f({ a = "a" }) {}
+>f : Symbol(f, Decl(a.js, 0, 0))
+>a : Symbol(a, Decl(a.js, 8, 12))
+
diff --git a/tests/baselines/reference/optionalBindingParameters3.types b/tests/baselines/reference/optionalBindingParameters3.types
new file mode 100644
index 0000000000000..a67a838072694
--- /dev/null
+++ b/tests/baselines/reference/optionalBindingParameters3.types
@@ -0,0 +1,14 @@
+=== /a.js ===
+/**
+ * @typedef Foo
+ * @property {string} a
+ */
+
+/**
+ * @param {Foo} [options]
+ */
+function f({ a = "a" }) {}
+>f : ({ a }?: Foo) => void
+>a : string
+>"a" : "a"
+
diff --git a/tests/cases/conformance/es6/destructuring/optionalBindingParameters3.ts b/tests/cases/conformance/es6/destructuring/optionalBindingParameters3.ts
new file mode 100644
index 0000000000000..0a8e5cf584e39
--- /dev/null
+++ b/tests/cases/conformance/es6/destructuring/optionalBindingParameters3.ts
@@ -0,0 +1,14 @@
+// @checkJs: true
+// @allowJs: true
+// @noEmit: true
+// @filename: /a.js
+
+/**
+ * @typedef Foo
+ * @property {string} a
+ */
+
+/**
+ * @param {Foo} [options]
+ */
+function f({ a = "a" }) {}