From 50671c374c51383d80360963f8635c5a9af97eed Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <Daniel.Rosenwasser@microsoft.com>
Date: Fri, 18 Aug 2017 12:55:35 -0700
Subject: [PATCH] Try to provide a spelling suggestion when object literals
 have excess properties.

---
 src/compiler/checker.ts              | 21 ++++++++++++++++++---
 src/compiler/diagnosticMessages.json |  4 ++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 54388d09e7d..d2b51867217 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -9067,11 +9067,26 @@ namespace ts {
                                 else {
                                     // use the property's value declaration if the property is assigned inside the literal itself
                                     const objectLiteralDeclaration = source.symbol && firstOrUndefined(source.symbol.declarations);
+                                    let suggestion;
                                     if (prop.valueDeclaration && findAncestor(prop.valueDeclaration, d => d === objectLiteralDeclaration)) {
-                                        errorNode = prop.valueDeclaration;
+                                        const propDeclaration = prop.valueDeclaration as ObjectLiteralElementLike;
+                                        Debug.assertNode(propDeclaration, isObjectLiteralElementLike);
+
+                                        errorNode = propDeclaration;
+
+                                        const propNameNode = propDeclaration.name as Identifier;
+                                        Debug.assertNode(propNameNode, isIdentifier);
+                                        suggestion = getSuggestionForNonexistentProperty(propNameNode, target);
+                                    }
+
+                                    if (suggestion !== undefined) {
+                                        reportError(Diagnostics.Object_literal_may_only_specify_known_properties_but_0_does_not_exist_in_type_1_Did_you_mean_to_write_2,
+                                            symbolToString(prop), typeToString(target), unescapeLeadingUnderscores(suggestion));
+                                    }
+                                    else {
+                                        reportError(Diagnostics.Object_literal_may_only_specify_known_properties_and_0_does_not_exist_in_type_1,
+                                            symbolToString(prop), typeToString(target));
                                     }
-                                    reportError(Diagnostics.Object_literal_may_only_specify_known_properties_and_0_does_not_exist_in_type_1,
-                                        symbolToString(prop), typeToString(target));
                                 }
                             }
                             return true;
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 77e7f7e7b62..e7d292d57d1 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -1912,6 +1912,10 @@
         "category": "Error",
         "code": 2560
     },
+    "Object literal may only specify known properties, but '{0}' does not exist in type '{1}'. Did you mean to write '{2}'?": {
+        "category": "Error",
+        "code": 2561
+    },
     "JSX element attributes type '{0}' may not be a union type.": {
         "category": "Error",
         "code": 2600