From de318651f36c1e6d59175520f5a6c355c5003fba Mon Sep 17 00:00:00 2001
From: Philip Pesca <ppesca@ucsd.edu>
Date: Mon, 22 Oct 2018 23:03:09 -0700
Subject: [PATCH] Improve code fix for missing members

---
 src/services/codefixes/fixAddMissingMember.ts      |  4 ++++
 tests/cases/fourslash/codeFixAddMissingMember12.ts | 14 ++++++++++++++
 tests/cases/fourslash/codeFixAddMissingMember13.ts | 14 ++++++++++++++
 .../codeFixAddMissingMember_typeParameter.ts       |  2 +-
 4 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/codeFixAddMissingMember12.ts
 create mode 100644 tests/cases/fourslash/codeFixAddMissingMember13.ts

diff --git a/src/services/codefixes/fixAddMissingMember.ts b/src/services/codefixes/fixAddMissingMember.ts
index dda0903562a..d1d0afb9059 100644
--- a/src/services/codefixes/fixAddMissingMember.ts
+++ b/src/services/codefixes/fixAddMissingMember.ts
@@ -185,6 +185,10 @@ namespace ts.codefix {
             const widenedType = checker.getWidenedType(checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(otherExpression)));
             typeNode = checker.typeToTypeNode(widenedType, classDeclaration);
         }
+        else {
+            const contextualType = checker.getContextualType(token.parent as Expression);
+            typeNode = contextualType ? checker.typeToTypeNode(contextualType) : undefined;
+        }
         return typeNode || createKeywordTypeNode(SyntaxKind.AnyKeyword);
     }
 
diff --git a/tests/cases/fourslash/codeFixAddMissingMember12.ts b/tests/cases/fourslash/codeFixAddMissingMember12.ts
new file mode 100644
index 00000000000..c45939f1d17
--- /dev/null
+++ b/tests/cases/fourslash/codeFixAddMissingMember12.ts
@@ -0,0 +1,14 @@
+/// <reference path='fourslash.ts' />
+
+//// class C {}
+//// const x: number = new C().x;
+
+verify.codeFix({
+    description: "Declare property 'x'",
+    index: 0,
+    newFileContent:
+`class C {
+    x: number;
+}
+const x: number = new C().x;`
+});
diff --git a/tests/cases/fourslash/codeFixAddMissingMember13.ts b/tests/cases/fourslash/codeFixAddMissingMember13.ts
new file mode 100644
index 00000000000..17c6f3aa0e1
--- /dev/null
+++ b/tests/cases/fourslash/codeFixAddMissingMember13.ts
@@ -0,0 +1,14 @@
+/// <reference path='fourslash.ts' />
+
+//// class C {}
+//// const x: number = new C().x;
+
+verify.codeFix({
+    description: "Add index signature for property 'x'",
+    index: 1,
+    newFileContent:
+`class C {
+    [x: string]: number;
+}
+const x: number = new C().x;`
+});
diff --git a/tests/cases/fourslash/codeFixAddMissingMember_typeParameter.ts b/tests/cases/fourslash/codeFixAddMissingMember_typeParameter.ts
index 51d476220bb..cbf31744b3b 100644
--- a/tests/cases/fourslash/codeFixAddMissingMember_typeParameter.ts
+++ b/tests/cases/fourslash/codeFixAddMissingMember_typeParameter.ts
@@ -19,7 +19,7 @@ verify.codeFix({
     index: 0,
     newFileContent:
 `interface I {
-    bar: any;
+    bar: number;
 }
 
 function f<T>(t: T): number {