From c3a1152895227d37871b383dd8fa5ad3c7361880 Mon Sep 17 00:00:00 2001
From: Herrington Darkholme <nonamesheep1@gmail.com>
Date: Wed, 2 Nov 2016 20:27:53 +0800
Subject: [PATCH] fix #11480, disallow delete operator on readonly property or
 index signature

---
 src/compiler/checker.ts              | 3 +++
 src/compiler/diagnosticMessages.json | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 744d23a3657a1..109e30979a94c 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -13486,6 +13486,9 @@ namespace ts {
 
         function checkDeleteExpression(node: DeleteExpression): Type {
             checkExpression(node.expression);
+            checkReferenceExpression(node.expression,
+                Diagnostics.The_operand_of_a_delete_operator_must_be_a_property_reference,
+                Diagnostics.The_operand_of_a_delete_operator_cannot_be_a_read_only_property);
             return booleanType;
         }
 
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 3b873cf35c04e..f448f848c05b7 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1971,6 +1971,14 @@
         "category": "Error",
         "code": 2697
     },
+    "The operand of a delete operator must be a property reference": {
+        "category": "Error",
+        "code": 2698
+    },
+    "The operand of a delete operator cannot be a read-only property": {
+        "category": "Error",
+        "code": 2699
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",