From ac03ba4f021fce5a78bcdde39952879d0a4f35eb Mon Sep 17 00:00:00 2001
From: magic-akari <akari.ccino@gmail.com>
Date: Fri, 6 Jun 2025 07:37:47 +0800
Subject: [PATCH] fix(checker): report error when using bigint as enum key
 (#61777)

---
 src/compiler/checker.ts                            |  4 ++++
 .../baselines/reference/enumWithBigint.errors.txt  | 10 ++++++++++
 tests/baselines/reference/enumWithBigint.js        | 13 +++++++++++++
 tests/baselines/reference/enumWithBigint.symbols   | 10 ++++++++++
 tests/baselines/reference/enumWithBigint.types     | 14 ++++++++++++++
 tests/cases/compiler/enumWithBigint.ts             |  3 +++
 6 files changed, 54 insertions(+)
 create mode 100644 tests/baselines/reference/enumWithBigint.errors.txt
 create mode 100644 tests/baselines/reference/enumWithBigint.js
 create mode 100644 tests/baselines/reference/enumWithBigint.symbols
 create mode 100644 tests/baselines/reference/enumWithBigint.types
 create mode 100644 tests/cases/compiler/enumWithBigint.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index acfb4003c85..eff1b31cd92 100644
--- a/src/compiler/checker.ts
+++ b/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)) {
diff --git a/tests/baselines/reference/enumWithBigint.errors.txt b/tests/baselines/reference/enumWithBigint.errors.txt
new file mode 100644
index 00000000000..a88660ce7c7
--- /dev/null
+++ b/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.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/enumWithBigint.js b/tests/baselines/reference/enumWithBigint.js
new file mode 100644
index 00000000000..9b8880af092
--- /dev/null
+++ b/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 = {}));
diff --git a/tests/baselines/reference/enumWithBigint.symbols b/tests/baselines/reference/enumWithBigint.symbols
new file mode 100644
index 00000000000..7f1b4d87aa9
--- /dev/null
+++ b/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))
+}
+
diff --git a/tests/baselines/reference/enumWithBigint.types b/tests/baselines/reference/enumWithBigint.types
new file mode 100644
index 00000000000..8b38b838e6a
--- /dev/null
+++ b/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
+>  : ^
+}
+
diff --git a/tests/cases/compiler/enumWithBigint.ts b/tests/cases/compiler/enumWithBigint.ts
new file mode 100644
index 00000000000..0add71d1d8d
--- /dev/null
+++ b/tests/cases/compiler/enumWithBigint.ts
@@ -0,0 +1,3 @@
+enum E {
+  0n = 0,
+}