fix(checker): report error when using bigint as enum key (microsoft#6…

…1777)

src/compiler/checker.ts

@@ -481,6 +481,7 @@ import {
     isAssignmentTarget,
     isAutoAccessorPropertyDeclaration,
     isAwaitExpression,
+    isBigIntLiteral,
     isBinaryExpression,
     isBinaryLogicalOperator,
     isBindableObjectDefinePropertyCall,
@@ -47541,6 +47542,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         if (isComputedNonLiteralName(member.name)) {
             error(member.name, Diagnostics.Computed_property_names_are_not_allowed_in_enums);
         }
+        else if (isBigIntLiteral(member.name)) {
+            error(member.name, Diagnostics.An_enum_member_cannot_have_a_numeric_name);
+        }
         else {
             const text = getTextOfPropertyName(member.name);
             if (isNumericLiteralName(text) && !isInfinityOrNaNString(text)) {

tests/baselines/reference/enumWithBigint.errors.txt

@@ -0,0 +1,10 @@
+enumWithBigint.ts(2,3): error TS2452: An enum member cannot have a numeric name.
+
+
+==== enumWithBigint.ts (1 errors) ====
+    enum E {
+      0n = 0,
+      ~~
+!!! error TS2452: An enum member cannot have a numeric name.
+    }
+

tests/baselines/reference/enumWithBigint.js

@@ -0,0 +1,13 @@
+//// [tests/cases/compiler/enumWithBigint.ts] ////
+
+//// [enumWithBigint.ts]
+enum E {
+  0n = 0,
+}
+
+
+//// [enumWithBigint.js]
+var E;
+(function (E) {
+    E[E[0n] = 0] = 0n;
+})(E || (E = {}));

tests/baselines/reference/enumWithBigint.symbols

@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/enumWithBigint.ts] ////
+
+=== enumWithBigint.ts ===
+enum E {
+>E : Symbol(E, Decl(enumWithBigint.ts, 0, 0))
+
+  0n = 0,
+>0n : Symbol(E[0n], Decl(enumWithBigint.ts, 0, 8))
+}
+

tests/baselines/reference/enumWithBigint.types

@@ -0,0 +1,14 @@
+//// [tests/cases/compiler/enumWithBigint.ts] ////
+
+=== enumWithBigint.ts ===
+enum E {
+>E : E
+>  : ^
+
+  0n = 0,
+>0n : E.__missing
+>   : ^^^^^^^^^^^
+>0 : 0
+>  : ^
+}
+

tests/cases/compiler/enumWithBigint.ts

@@ -0,0 +1,3 @@
+enum E {
+  0n = 0,
+}