From d137e4a23b75730cf83c31350127aa8942d5ce25 Mon Sep 17 00:00:00 2001
From: Alexander T <alexander.tarasyuk@outlook.com>
Date: Thu, 2 Jul 2020 11:40:17 +0300
Subject: [PATCH] fix(39346): show completion in inherited classes from the
 composited base interface

---
 src/services/completions.ts                   |  2 +-
 .../completionListInheritedClassMembers.ts    | 43 +++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/completionListInheritedClassMembers.ts

diff --git a/src/services/completions.ts b/src/services/completions.ts
index 88cee321e1023..8708fc26fa2b7 100644
--- a/src/services/completions.ts
+++ b/src/services/completions.ts
@@ -2432,7 +2432,7 @@ namespace ts.Completions {
                 !existingMemberNames.has(propertySymbol.escapedName) &&
                 !!propertySymbol.declarations &&
                 !(getDeclarationModifierFlagsFromSymbol(propertySymbol) & ModifierFlags.Private) &&
-                !isPrivateIdentifierPropertyDeclaration(propertySymbol.valueDeclaration));
+                !(propertySymbol.valueDeclaration && isPrivateIdentifierPropertyDeclaration(propertySymbol.valueDeclaration)));
         }
 
         /**
diff --git a/tests/cases/fourslash/completionListInheritedClassMembers.ts b/tests/cases/fourslash/completionListInheritedClassMembers.ts
new file mode 100644
index 0000000000000..334374eab44d2
--- /dev/null
+++ b/tests/cases/fourslash/completionListInheritedClassMembers.ts
@@ -0,0 +1,43 @@
+/// <reference path="fourslash.ts"/>
+
+// @filename: a.ts
+////interface I {
+////    m2(): void;
+////    m3(): void;
+////}
+////
+////type T1 = I;
+////export interface A1 extends T1 {
+////    m1(): void;
+////}
+////export class A1 {}
+////
+////type T2 = Partial<I>
+////export interface A2 extends T2 {
+////    m1(): void;
+////}
+////export class A2 {}
+////
+////type T3 = Pick<I, "m3">
+////export interface A3 extends T3 {
+////    m1(): void;
+////}
+////export class A3 {}
+
+// @filename: b.ts
+////import { A1, A2, A3 } from './a';
+////class B1 extends A1 {
+////    /*1*/
+////}
+////class B2 extends A2 {
+////    /*2*/
+////}
+////class B3 extends A3 {
+////    /*3*/
+////}
+
+verify.completions(
+    { marker: "1", exact: ["m1", "m2", "m3", ...completion.classElementKeywords], isNewIdentifierLocation: true },
+    { marker: "2", exact: ["m1", "m2", "m3", ...completion.classElementKeywords], isNewIdentifierLocation: true },
+    { marker: "3", exact: ["m1", "m3", ...completion.classElementKeywords], isNewIdentifierLocation: true }
+);