From c63b9f4c41df726bc4fe5e4144de1df43210ed63 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Burzy=C5=84ski?= <mateuszburzynski@gmail.com>
Date: Tue, 22 Nov 2022 00:21:45 +0100
Subject: [PATCH] Fixed substition types for non-generic indexed accesses

---
 src/compiler/checker.ts                                |  3 +--
 ...stitutionTypeForNonGenericIndexedAccessType.symbols | 10 ++++++++++
 ...ubstitutionTypeForNonGenericIndexedAccessType.types |  6 ++++++
 .../substitutionTypeForNonGenericIndexedAccessType.ts  |  6 ++++++
 4 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.symbols
 create mode 100644 tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.types
 create mode 100644 tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8bb8f3869ee44..91ce0e0a147eb 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -15019,8 +15019,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     }
 
     function getSubstitutionType(baseType: Type, constraint: Type) {
-        if (constraint.flags & TypeFlags.AnyOrUnknown || constraint === baseType ||
-            !isGenericType(baseType) && !isGenericType(constraint)) {
+        if (constraint.flags & TypeFlags.AnyOrUnknown || constraint === baseType) {
             return baseType;
         }
         const id = `${getTypeId(baseType)}>${getTypeId(constraint)}`;
diff --git a/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.symbols b/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.symbols
new file mode 100644
index 0000000000000..bb0d2675e36b0
--- /dev/null
+++ b/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.symbols
@@ -0,0 +1,10 @@
+=== tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts ===
+interface A {}
+>A : Symbol(A, Decl(substitutionTypeForNonGenericIndexedAccessType.ts, 0, 0))
+
+type B = A extends Record<'foo', string> ? A['foo'] : string; // no error
+>B : Symbol(B, Decl(substitutionTypeForNonGenericIndexedAccessType.ts, 0, 14))
+>A : Symbol(A, Decl(substitutionTypeForNonGenericIndexedAccessType.ts, 0, 0))
+>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
+>A : Symbol(A, Decl(substitutionTypeForNonGenericIndexedAccessType.ts, 0, 0))
+
diff --git a/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.types b/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.types
new file mode 100644
index 0000000000000..2846f2f192315
--- /dev/null
+++ b/tests/baselines/reference/substitutionTypeForNonGenericIndexedAccessType.types
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts ===
+interface A {}
+
+type B = A extends Record<'foo', string> ? A['foo'] : string; // no error
+>B : string
+
diff --git a/tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts b/tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts
new file mode 100644
index 0000000000000..bc78add75a1d4
--- /dev/null
+++ b/tests/cases/compiler/substitutionTypeForNonGenericIndexedAccessType.ts
@@ -0,0 +1,6 @@
+// @strict: true
+// @noEmit: true
+
+interface A {}
+
+type B = A extends Record<'foo', string> ? A['foo'] : string; // no error