From 2c31e25c1c94291a9d4622c18d3118581e82652d Mon Sep 17 00:00:00 2001
From: Marve10s <igrimanigroman@gmail.com>
Date: Sun, 25 Oct 2026 22:29:43 +0300
Subject: [PATCH] Reject negative fractional enum values in TypeScript Codegen

---
 .../typescript-module-parser-e2e-test.js      | 21 +++++++++++++++++++
 .../src/parsers/typescript/modules/index.js   | 17 +++++++++------
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/packages/react-native-codegen/src/parsers/typescript/modules/__tests__/typescript-module-parser-e2e-test.js b/packages/react-native-codegen/src/parsers/typescript/modules/__tests__/typescript-module-parser-e2e-test.js
index 540f388168ba..eb1a4b8f11b9 100644
--- a/packages/react-native-codegen/src/parsers/typescript/modules/__tests__/typescript-module-parser-e2e-test.js
+++ b/packages/react-native-codegen/src/parsers/typescript/modules/__tests__/typescript-module-parser-e2e-test.js
@@ -18,6 +18,7 @@ import type {
 const {
   MissingTypeParameterGenericParserError,
   UnnamedFunctionParamParserError,
+  UnsupportedEnumDeclarationParserError,
   UnsupportedGenericParserError,
   UnsupportedTypeAnnotationParserError,
 } = require('../../../errors');
@@ -146,6 +147,26 @@ describe('TypeScript Module Parser', () => {
       ]);
     });
 
+    it.each([
+      'VALUE = -1.5',
+      'ZERO = 0, VALUE = -1.5',
+      'VALUE = -1e-2',
+      'VALUE = -(1.5)',
+    ])('should reject fractional enum members: %s', members => {
+      const parser = () =>
+        parseModule(`
+          import type {TurboModule} from 'RCTExport';
+          import * as TurboModuleRegistry from 'TurboModuleRegistry';
+          enum MyEnum { ${members} }
+          export interface Spec extends TurboModule {
+            useArg(arg: MyEnum): void;
+          }
+          export default TurboModuleRegistry.get<Spec>('Foo');
+        `);
+
+      expect(parser).toThrow(UnsupportedEnumDeclarationParserError);
+    });
+
     it('should properly parse enums', () => {
       const parser = () =>
         parseModule(`
diff --git a/packages/react-native-codegen/src/parsers/typescript/modules/index.js b/packages/react-native-codegen/src/parsers/typescript/modules/index.js
index a5925aecef32..35112d5bbdd7 100644
--- a/packages/react-native-codegen/src/parsers/typescript/modules/index.js
+++ b/packages/react-native-codegen/src/parsers/typescript/modules/index.js
@@ -362,12 +362,17 @@ function translateTypeAnnotation(
     }
     case 'TSEnumDeclaration': {
       if (
-        typeAnnotation.members.some(
-          m =>
-            m.initializer &&
-            m.initializer.type === 'NumericLiteral' &&
-            !Number.isInteger(m.initializer.value),
-        )
+        typeAnnotation.members.some(m => {
+          const initializer =
+            m.initializer?.type === 'UnaryExpression' &&
+            m.initializer.operator === '-'
+              ? m.initializer.argument
+              : m.initializer;
+          return (
+            initializer?.type === 'NumericLiteral' &&
+            !Number.isInteger(initializer.value)
+          );
+        })
       ) {
         throw new UnsupportedEnumDeclarationParserError(
           hasteModuleName,