From 731a20a3c2c8cc805294f738b6a6c60877bdf06e Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Tue, 7 Jul 2020 15:37:00 -0700
Subject: [PATCH] Revert "Cherry-pick PR #38653 into release-3.9 (#38687)"

This reverts commit 9ec5fc5f35d9262be46d7b7f21ad5d6b8cc16ad5.
---
 src/compiler/checker.ts                       |  6 +--
 .../reference/circularContextualMappedType.js | 32 ------------
 .../circularContextualMappedType.symbols      | 51 -------------------
 .../circularContextualMappedType.types        | 50 ------------------
 .../compiler/circularContextualMappedType.ts  | 20 --------
 5 files changed, 1 insertion(+), 158 deletions(-)
 delete mode 100644 tests/baselines/reference/circularContextualMappedType.js
 delete mode 100644 tests/baselines/reference/circularContextualMappedType.symbols
 delete mode 100644 tests/baselines/reference/circularContextualMappedType.types
 delete mode 100644 tests/cases/compiler/circularContextualMappedType.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 18611a9f68780..f669ac4e4683d 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -22402,10 +22402,6 @@ namespace ts {
             }
         }
 
-        function isCircularMappedProperty(symbol: Symbol) {
-            return !!(getCheckFlags(symbol) & CheckFlags.Mapped && !(<MappedSymbol>symbol).type && findResolutionCycleStartIndex(symbol, TypeSystemPropertyName.Type) >= 0);
-        }
-
         function getTypeOfPropertyOfContextualType(type: Type, name: __String) {
             return mapType(type, t => {
                 if (isGenericMappedType(t)) {
@@ -22419,7 +22415,7 @@ namespace ts {
                 else if (t.flags & TypeFlags.StructuredType) {
                     const prop = getPropertyOfType(t, name);
                     if (prop) {
-                        return isCircularMappedProperty(prop) ? undefined : getTypeOfSymbol(prop);
+                        return getTypeOfSymbol(prop);
                     }
                     if (isTupleType(t)) {
                         const restType = getRestTypeOfTupleType(t);
diff --git a/tests/baselines/reference/circularContextualMappedType.js b/tests/baselines/reference/circularContextualMappedType.js
deleted file mode 100644
index 7bd989c843a80..0000000000000
--- a/tests/baselines/reference/circularContextualMappedType.js
+++ /dev/null
@@ -1,32 +0,0 @@
-//// [circularContextualMappedType.ts]
-type Func<T> = () => T;
-
-type Mapped<T> = { [K in keyof T]: Func<T[K]> };
-
-declare function reproduce(options: number): void;
-declare function reproduce<T>(options: Mapped<T>): T
-
-reproduce({
-  name:   () => { return 123 }
-});
-
-reproduce({
-  name() { return 123 }
-});
-
-reproduce({
-  name: function () { return 123 }
-});
-
-
-//// [circularContextualMappedType.js]
-"use strict";
-reproduce({
-    name: function () { return 123; }
-});
-reproduce({
-    name: function () { return 123; }
-});
-reproduce({
-    name: function () { return 123; }
-});
diff --git a/tests/baselines/reference/circularContextualMappedType.symbols b/tests/baselines/reference/circularContextualMappedType.symbols
deleted file mode 100644
index 445906d48c1c7..0000000000000
--- a/tests/baselines/reference/circularContextualMappedType.symbols
+++ /dev/null
@@ -1,51 +0,0 @@
-=== tests/cases/compiler/circularContextualMappedType.ts ===
-type Func<T> = () => T;
->Func : Symbol(Func, Decl(circularContextualMappedType.ts, 0, 0))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 0, 10))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 0, 10))
-
-type Mapped<T> = { [K in keyof T]: Func<T[K]> };
->Mapped : Symbol(Mapped, Decl(circularContextualMappedType.ts, 0, 23))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 2, 12))
->K : Symbol(K, Decl(circularContextualMappedType.ts, 2, 20))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 2, 12))
->Func : Symbol(Func, Decl(circularContextualMappedType.ts, 0, 0))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 2, 12))
->K : Symbol(K, Decl(circularContextualMappedType.ts, 2, 20))
-
-declare function reproduce(options: number): void;
->reproduce : Symbol(reproduce, Decl(circularContextualMappedType.ts, 2, 48), Decl(circularContextualMappedType.ts, 4, 50))
->options : Symbol(options, Decl(circularContextualMappedType.ts, 4, 27))
-
-declare function reproduce<T>(options: Mapped<T>): T
->reproduce : Symbol(reproduce, Decl(circularContextualMappedType.ts, 2, 48), Decl(circularContextualMappedType.ts, 4, 50))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 5, 27))
->options : Symbol(options, Decl(circularContextualMappedType.ts, 5, 30))
->Mapped : Symbol(Mapped, Decl(circularContextualMappedType.ts, 0, 23))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 5, 27))
->T : Symbol(T, Decl(circularContextualMappedType.ts, 5, 27))
-
-reproduce({
->reproduce : Symbol(reproduce, Decl(circularContextualMappedType.ts, 2, 48), Decl(circularContextualMappedType.ts, 4, 50))
-
-  name:   () => { return 123 }
->name : Symbol(name, Decl(circularContextualMappedType.ts, 7, 11))
-
-});
-
-reproduce({
->reproduce : Symbol(reproduce, Decl(circularContextualMappedType.ts, 2, 48), Decl(circularContextualMappedType.ts, 4, 50))
-
-  name() { return 123 }
->name : Symbol(name, Decl(circularContextualMappedType.ts, 11, 11))
-
-});
-
-reproduce({
->reproduce : Symbol(reproduce, Decl(circularContextualMappedType.ts, 2, 48), Decl(circularContextualMappedType.ts, 4, 50))
-
-  name: function () { return 123 }
->name : Symbol(name, Decl(circularContextualMappedType.ts, 15, 11))
-
-});
-
diff --git a/tests/baselines/reference/circularContextualMappedType.types b/tests/baselines/reference/circularContextualMappedType.types
deleted file mode 100644
index d9439215d280e..0000000000000
--- a/tests/baselines/reference/circularContextualMappedType.types
+++ /dev/null
@@ -1,50 +0,0 @@
-=== tests/cases/compiler/circularContextualMappedType.ts ===
-type Func<T> = () => T;
->Func : Func<T>
-
-type Mapped<T> = { [K in keyof T]: Func<T[K]> };
->Mapped : Mapped<T>
-
-declare function reproduce(options: number): void;
->reproduce : { (options: number): void; <T>(options: Mapped<T>): T; }
->options : number
-
-declare function reproduce<T>(options: Mapped<T>): T
->reproduce : { (options: number): void; <T>(options: Mapped<T>): T; }
->options : Mapped<T>
-
-reproduce({
->reproduce({  name:   () => { return 123 }}) : { name: number; }
->reproduce : { (options: number): void; <T>(options: Mapped<T>): T; }
->{  name:   () => { return 123 }} : { name: () => number; }
-
-  name:   () => { return 123 }
->name : () => number
->() => { return 123 } : () => number
->123 : 123
-
-});
-
-reproduce({
->reproduce({  name() { return 123 }}) : { name: number; }
->reproduce : { (options: number): void; <T>(options: Mapped<T>): T; }
->{  name() { return 123 }} : { name(): number; }
-
-  name() { return 123 }
->name : () => number
->123 : 123
-
-});
-
-reproduce({
->reproduce({  name: function () { return 123 }}) : { name: number; }
->reproduce : { (options: number): void; <T>(options: Mapped<T>): T; }
->{  name: function () { return 123 }} : { name: () => number; }
-
-  name: function () { return 123 }
->name : () => number
->function () { return 123 } : () => number
->123 : 123
-
-});
-
diff --git a/tests/cases/compiler/circularContextualMappedType.ts b/tests/cases/compiler/circularContextualMappedType.ts
deleted file mode 100644
index 4c982cd6fca1f..0000000000000
--- a/tests/cases/compiler/circularContextualMappedType.ts
+++ /dev/null
@@ -1,20 +0,0 @@
-// @strict: true
-
-type Func<T> = () => T;
-
-type Mapped<T> = { [K in keyof T]: Func<T[K]> };
-
-declare function reproduce(options: number): void;
-declare function reproduce<T>(options: Mapped<T>): T
-
-reproduce({
-  name:   () => { return 123 }
-});
-
-reproduce({
-  name() { return 123 }
-});
-
-reproduce({
-  name: function () { return 123 }
-});