From 8eeb763cdd2bf7611fc98a430d5a9d47e8545a5e Mon Sep 17 00:00:00 2001
From: Klaus Meinhardt <klaus.meinhardt1@gmail.com>
Date: Wed, 14 Aug 2019 21:00:19 +0200
Subject: [PATCH] report invalid modifiers on class expression properties

Fixes: #32532
---
 src/compiler/checker.ts                            |  4 ++--
 .../classExpressionPropertyModifiers.errors.txt    | 14 ++++++++++++++
 .../compiler/classExpressionPropertyModifiers.ts   |  8 ++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/classExpressionPropertyModifiers.errors.txt
 create mode 100644 tests/cases/compiler/classExpressionPropertyModifiers.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 9d6fa60306c..74bf936d5c8 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -32406,7 +32406,7 @@ namespace ts {
                         else if (flags & ModifierFlags.Async) {
                             return grammarErrorOnNode(modifier, Diagnostics._0_modifier_must_precede_1_modifier, "export", "async");
                         }
-                        else if (node.parent.kind === SyntaxKind.ClassDeclaration) {
+                        else if (isClassLike(node.parent)) {
                             return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_appear_on_a_class_element, "export");
                         }
                         else if (node.kind === SyntaxKind.Parameter) {
@@ -32429,7 +32429,7 @@ namespace ts {
                         else if (flags & ModifierFlags.Async) {
                             return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_be_used_in_an_ambient_context, "async");
                         }
-                        else if (node.parent.kind === SyntaxKind.ClassDeclaration) {
+                        else if (isClassLike(node.parent)) {
                             return grammarErrorOnNode(modifier, Diagnostics._0_modifier_cannot_appear_on_a_class_element, "declare");
                         }
                         else if (node.kind === SyntaxKind.Parameter) {
diff --git a/tests/baselines/reference/classExpressionPropertyModifiers.errors.txt b/tests/baselines/reference/classExpressionPropertyModifiers.errors.txt
new file mode 100644
index 00000000000..f4b3fed7e54
--- /dev/null
+++ b/tests/baselines/reference/classExpressionPropertyModifiers.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/compiler/classExpressionPropertyModifiers.ts(2,5): error TS1031: 'declare' modifier cannot appear on a class element.
+tests/cases/compiler/classExpressionPropertyModifiers.ts(3,5): error TS1031: 'export' modifier cannot appear on a class element.
+
+
+==== tests/cases/compiler/classExpressionPropertyModifiers.ts (2 errors) ====
+    const a = class Cat {
+        declare [Symbol.toStringTag] = "uh";
+        ~~~~~~~
+!!! error TS1031: 'declare' modifier cannot appear on a class element.
+        export foo = 1;
+        ~~~~~~
+!!! error TS1031: 'export' modifier cannot appear on a class element.
+    }
+    
\ No newline at end of file
diff --git a/tests/cases/compiler/classExpressionPropertyModifiers.ts b/tests/cases/compiler/classExpressionPropertyModifiers.ts
new file mode 100644
index 00000000000..be9e66eea8e
--- /dev/null
+++ b/tests/cases/compiler/classExpressionPropertyModifiers.ts
@@ -0,0 +1,8 @@
+// @noEmit: true
+// @noTypesAndSymbols: true
+// @lib: es6
+
+const a = class Cat {
+    declare [Symbol.toStringTag] = "uh";
+    export foo = 1;
+}