From aef2e0a238453c12ee5ca2bc2090c44d13bf8408 Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrewbranch@users.noreply.github.com>
Date: Wed, 18 Dec 2019 07:20:01 -0800
Subject: [PATCH] Fix implement interface codefix for synthetic member symbols
 (#35718)

---
 .../fixClassIncorrectlyImplementsInterface.ts |  2 +-
 .../codefixClassImplementInterface_omit.ts    | 30 +++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/codefixClassImplementInterface_omit.ts

diff --git a/src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts b/src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts
index ddd5bacea26..0735e85bc70 100644
--- a/src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts
+++ b/src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts
@@ -34,7 +34,7 @@ namespace ts.codefix {
     }
 
     function symbolPointsToNonPrivateMember (symbol: Symbol) {
-        return !(getModifierFlags(symbol.valueDeclaration) & ModifierFlags.Private);
+        return !symbol.valueDeclaration || !(getModifierFlags(symbol.valueDeclaration) & ModifierFlags.Private);
     }
 
     function addMissingDeclarations(
diff --git a/tests/cases/fourslash/codefixClassImplementInterface_omit.ts b/tests/cases/fourslash/codefixClassImplementInterface_omit.ts
new file mode 100644
index 00000000000..f4ff82028d4
--- /dev/null
+++ b/tests/cases/fourslash/codefixClassImplementInterface_omit.ts
@@ -0,0 +1,30 @@
+/// <reference path="fourslash.ts" />
+
+////interface One {
+////    a: number;
+////    b: string;
+////}
+////
+////interface Two extends Omit<One, "a"> {
+////    c: boolean;
+////}
+////
+////class TwoStore implements Two {[| |]}
+
+verify.codeFix({
+  description: "Implement interface 'Two'",
+  newFileContent:
+`interface One {
+    a: number;
+    b: string;
+}
+
+interface Two extends Omit<One, "a"> {
+    c: boolean;
+}
+
+class TwoStore implements Two {
+    c: boolean;
+    b: string;
+}`,
+});