Fixed an incorrect assumption K in Union works with numeric literals

src/compiler/checker.ts

@@ -25781,7 +25781,7 @@ namespace ts {
                     return grammarErrorOnNode(parameter.name, Diagnostics.An_index_signature_parameter_type_cannot_be_a_type_alias_Use_index_Colon_0_instead, typeToString(type));
                 }
 
-                if (type.flags & TypeFlags.Union && every((<UnionType>type).types, t => !!(t.flags & TypeFlags.StringOrNumberLiteral))) {
+                if (type.flags & TypeFlags.Union && every((<UnionType>type).types, t => !!(t.flags & TypeFlags.StringLiteral))) {
                     return grammarErrorOnNode(parameter.name, Diagnostics.An_index_signature_parameter_type_cannot_be_a_union_type_Use_K_in_0_instead, symbolName(type.aliasSymbol));
                 }
 

tests/baselines/reference/indexerConstraints2.errors.txt

@@ -8,10 +8,9 @@ tests/cases/compiler/indexerConstraints2.ts(52,6): error TS1337: An index signat
 tests/cases/compiler/indexerConstraints2.ts(58,6): error TS1023: An index signature parameter type must be 'string' or 'number'.
 tests/cases/compiler/indexerConstraints2.ts(64,6): error TS1023: An index signature parameter type must be 'string' or 'number'.
 tests/cases/compiler/indexerConstraints2.ts(70,6): error TS1023: An index signature parameter type must be 'string' or 'number'.
-tests/cases/compiler/indexerConstraints2.ts(76,6): error TS1023: An index signature parameter type must be 'string' or 'number'.
 
 
-==== tests/cases/compiler/indexerConstraints2.ts (11 errors) ====
+==== tests/cases/compiler/indexerConstraints2.ts (10 errors) ====
     class A { a: number; }
     class B extends A { b: number; }
     
@@ -72,7 +71,7 @@ tests/cases/compiler/indexerConstraints2.ts(76,6): error TS1023: An index signat
 !!! error TS1023: An index signature parameter type must be 'string' or 'number'.
     }
     
-    type IndexableUnion = "foo" | 42;
+    type IndexableUnion = "foo" | "bar";
     
     interface O {
         [u: IndexableUnion]: A;
@@ -96,18 +95,10 @@ tests/cases/compiler/indexerConstraints2.ts(76,6): error TS1023: An index signat
 !!! error TS1023: An index signature parameter type must be 'string' or 'number'.
     }
     
-    type NonIndexableUnion3 = 42 | string;
+    type NonIndexableUnion3 = "foo" | 42;
     
     interface R {
         [u: NonIndexableUnion3]: A;
          ~
-!!! error TS1023: An index signature parameter type must be 'string' or 'number'.
-    }
-    
-    type NonIndexableUnion4 = "foo" | number;
-    
-    interface S {
-        [u: NonIndexableUnion4]: A;
-         ~
 !!! error TS1023: An index signature parameter type must be 'string' or 'number'.
     }

tests/baselines/reference/indexerConstraints2.js

@@ -47,7 +47,7 @@ interface N {
     [b: AliasedBoolean]: A;
 }
 
-type IndexableUnion = "foo" | 42;
+type IndexableUnion = "foo" | "bar";
 
 interface O {
     [u: IndexableUnion]: A;
@@ -65,16 +65,10 @@ interface Q {
     [u: NonIndexableUnion2]: A;
 }
 
-type NonIndexableUnion3 = 42 | string;
+type NonIndexableUnion3 = "foo" | 42;
 
 interface R {
     [u: NonIndexableUnion3]: A;
-}
-
-type NonIndexableUnion4 = "foo" | number;
-
-interface S {
-    [u: NonIndexableUnion4]: A;
 }
 
 //// [indexerConstraints2.js]

tests/baselines/reference/indexerConstraints2.symbols

@@ -100,11 +100,11 @@ interface N {
 >A : Symbol(A, Decl(indexerConstraints2.ts, 0, 0))
 }
 
-type IndexableUnion = "foo" | 42;
+type IndexableUnion = "foo" | "bar";
 >IndexableUnion : Symbol(IndexableUnion, Decl(indexerConstraints2.ts, 46, 1))
 
 interface O {
->O : Symbol(O, Decl(indexerConstraints2.ts, 48, 33))
+>O : Symbol(O, Decl(indexerConstraints2.ts, 48, 36))
 
     [u: IndexableUnion]: A;
 >u : Symbol(u, Decl(indexerConstraints2.ts, 51, 5))
@@ -136,26 +136,14 @@ interface Q {
 >A : Symbol(A, Decl(indexerConstraints2.ts, 0, 0))
 }
 
-type NonIndexableUnion3 = 42 | string;
+type NonIndexableUnion3 = "foo" | 42;
 >NonIndexableUnion3 : Symbol(NonIndexableUnion3, Decl(indexerConstraints2.ts, 64, 1))
 
 interface R {
->R : Symbol(R, Decl(indexerConstraints2.ts, 66, 38))
+>R : Symbol(R, Decl(indexerConstraints2.ts, 66, 37))
 
     [u: NonIndexableUnion3]: A;
 >u : Symbol(u, Decl(indexerConstraints2.ts, 69, 5))
 >NonIndexableUnion3 : Symbol(NonIndexableUnion3, Decl(indexerConstraints2.ts, 64, 1))
 >A : Symbol(A, Decl(indexerConstraints2.ts, 0, 0))
 }
-
-type NonIndexableUnion4 = "foo" | number;
->NonIndexableUnion4 : Symbol(NonIndexableUnion4, Decl(indexerConstraints2.ts, 70, 1))
-
-interface S {
->S : Symbol(S, Decl(indexerConstraints2.ts, 72, 41))
-
-    [u: NonIndexableUnion4]: A;
->u : Symbol(u, Decl(indexerConstraints2.ts, 75, 5))
->NonIndexableUnion4 : Symbol(NonIndexableUnion4, Decl(indexerConstraints2.ts, 70, 1))
->A : Symbol(A, Decl(indexerConstraints2.ts, 0, 0))
-}

tests/baselines/reference/indexerConstraints2.types

@@ -100,7 +100,7 @@ interface N {
 >A : A
 }
 
-type IndexableUnion = "foo" | 42;
+type IndexableUnion = "foo" | "bar";
 >IndexableUnion : IndexableUnion
 
 interface O {
@@ -136,7 +136,7 @@ interface Q {
 >A : A
 }
 
-type NonIndexableUnion3 = 42 | string;
+type NonIndexableUnion3 = "foo" | 42;
 >NonIndexableUnion3 : NonIndexableUnion3
 
 interface R {
@@ -147,15 +147,3 @@ interface R {
 >NonIndexableUnion3 : NonIndexableUnion3
 >A : A
 }
-
-type NonIndexableUnion4 = "foo" | number;
->NonIndexableUnion4 : NonIndexableUnion4
-
-interface S {
->S : S
-
-    [u: NonIndexableUnion4]: A;
->u : NonIndexableUnion4
->NonIndexableUnion4 : NonIndexableUnion4
->A : A
-}

tests/cases/compiler/indexerConstraints2.ts

@@ -46,7 +46,7 @@ interface N {
     [b: AliasedBoolean]: A;
 }
 
-type IndexableUnion = "foo" | 42;
+type IndexableUnion = "foo" | "bar";
 
 interface O {
     [u: IndexableUnion]: A;
@@ -64,14 +64,8 @@ interface Q {
     [u: NonIndexableUnion2]: A;
 }
 
-type NonIndexableUnion3 = 42 | string;
+type NonIndexableUnion3 = "foo" | 42;
 
 interface R {
     [u: NonIndexableUnion3]: A;
-}
-
-type NonIndexableUnion4 = "foo" | number;
-
-interface S {
-    [u: NonIndexableUnion4]: A;
 }