From cd0d3babe9d4d79b51fa75c55707901a6579d92f Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 8 Jul 2015 19:04:58 -0700
Subject: [PATCH] Object literals can only have properties that exist in
 contextual type

---
 src/compiler/checker.ts                           | 15 +++++++++++++++
 .../diagnosticInformationMap.generated.ts         |  1 +
 src/compiler/diagnosticMessages.json              |  4 ++++
 3 files changed, 20 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1edd2a7a920..29922f17e33 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6830,6 +6830,18 @@ namespace ts {
             return links.resolvedType;
         }
 
+        function isPermittedProperty(contextualType: Type, propName: string): boolean {
+            if (contextualType.flags & TypeFlags.ObjectType) {
+                let resolved = resolveStructuredTypeMembers(<ObjectType>contextualType);
+                return !!(resolved.properties.length === 0 || resolved.stringIndexType ||
+                    resolved.numberIndexType || getPropertyOfObjectType(contextualType, propName));
+            }
+            if (contextualType.flags & TypeFlags.UnionOrIntersection) {
+                return !forEach((<UnionOrIntersectionType>contextualType).types, type => !isPermittedProperty(type, propName));
+            }
+            return true;
+        }
+
         function checkObjectLiteral(node: ObjectLiteralExpression, contextualMapper?: TypeMapper): Type {
             // Grammar checking
             checkGrammarObjectLiteralExpression(node);
@@ -6879,6 +6891,9 @@ namespace ts {
 
                 if (!hasDynamicName(memberDecl)) {
                     propertiesTable[member.name] = member;
+                    if (contextualType && !isPermittedProperty(contextualType, member.name)) {
+                        error(memberDecl.name, Diagnostics.Property_0_does_not_exist_in_contextual_type_1, member.name, typeToString(contextualType));
+                    }
                 }
                 propertiesArray.push(member);
             }
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
index a17f8857590..33f30abc4ab 100644
--- a/src/compiler/diagnosticInformationMap.generated.ts
+++ b/src/compiler/diagnosticInformationMap.generated.ts
@@ -414,6 +414,7 @@ namespace ts {
         The_arguments_object_cannot_be_referenced_in_an_async_arrow_function_Consider_using_a_standard_async_function_expression: { code: 2522, category: DiagnosticCategory.Error, key: "The 'arguments' object cannot be referenced in an async arrow function. Consider using a standard async function expression." },
         yield_expressions_cannot_be_used_in_a_parameter_initializer: { code: 2523, category: DiagnosticCategory.Error, key: "'yield' expressions cannot be used in a parameter initializer." },
         await_expressions_cannot_be_used_in_a_parameter_initializer: { code: 2524, category: DiagnosticCategory.Error, key: "'await' expressions cannot be used in a parameter initializer." },
+        Property_0_does_not_exist_in_contextual_type_1: { code: 2525, category: DiagnosticCategory.Error, key: "Property '{0}' does not exist in contextual type '{1}'." },
         JSX_element_attributes_type_0_must_be_an_object_type: { code: 2600, category: DiagnosticCategory.Error, key: "JSX element attributes type '{0}' must be an object type." },
         The_return_type_of_a_JSX_element_constructor_must_return_an_object_type: { code: 2601, category: DiagnosticCategory.Error, key: "The return type of a JSX element constructor must return an object type." },
         JSX_element_implicitly_has_type_any_because_the_global_type_JSX_Element_does_not_exist: { code: 2602, category: DiagnosticCategory.Error, key: "JSX element implicitly has type 'any' because the global type 'JSX.Element' does not exist." },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 94be4f53c97..8036009b974 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1645,6 +1645,10 @@
         "category": "Error",
         "code": 2524
     },
+    "Property '{0}' does not exist in contextual type '{1}'.": {
+        "category": "Error",
+        "code": 2525
+    },
     "JSX element attributes type '{0}' must be an object type.": {
         "category": "Error",
         "code": 2600