fix: use toWTFString for JSValue string conversion in initgroups

- Replace user.getString(globalObject) with user.toWTFString(globalObject)
- Fix compilation errors: JSString* type mismatch and missing utf8() method
- Proper exception handling with RETURN_IF_EXCEPTION

Co-authored-by: Jarred-Sumner <Jarred-Sumner@users.noreply.github.com>

src/bun.js/bindings/BunProcess.cpp

@@ -2335,7 +2335,7 @@ static JSValue constructEnv(VM& vm, JSObject* processObject)
     return globalObject->processEnvObject();
 }
 
-#if !OS(WINDOWS)
+#if OS(DARWIN) || OS(LINUX)
 
 JSC_DEFINE_HOST_FUNCTION(Process_functiongetuid, (JSGlobalObject * globalObject, CallFrame* callFrame))
 {
@@ -2527,6 +2527,59 @@ JSC_DEFINE_HOST_FUNCTION(Process_functionsetgroups, (JSGlobalObject * globalObje
     return JSValue::encode(jsNumber(result));
 }
 
+JSC_DEFINE_HOST_FUNCTION(Process_functioninitgroups, (JSGlobalObject * globalObject, CallFrame* callFrame))
+{
+    auto& vm = JSC::getVM(globalObject);
+    auto scope = DECLARE_THROW_SCOPE(vm);
+    JSValue user = callFrame->argument(0);
+    JSValue extraGroup = callFrame->argument(1);
+
+    if (!user.isNumber() && !user.isString())
+        return Bun::ERR::INVALID_ARG_TYPE(scope, globalObject, "user"_s, "number or string"_s, user);
+
+    if (!extraGroup.isNumber() && !extraGroup.isString())
+        return Bun::ERR::INVALID_ARG_TYPE(scope, globalObject, "extraGroup"_s, "number or string"_s, extraGroup);
+
+    gid_t gid = 0;
+    if (extraGroup.isNumber()) {
+        Bun::V::validateInteger(scope, globalObject, extraGroup, "extraGroup"_s, jsNumber(0), jsNumber(std::pow(2, 31) - 1), &gid);
+        RETURN_IF_EXCEPTION(scope, {});
+    } else {
+        extraGroup = maybe_gid_by_name(scope, globalObject, extraGroup);
+        RETURN_IF_EXCEPTION(scope, {});
+        gid = extraGroup.toUInt32(globalObject);
+    }
+
+    const char* username = nullptr;
+    struct passwd pwd;
+    struct passwd* pp = nullptr;
+    char buf[8192];
+    if (user.isNumber()) {
+        uint32_t uid = 0;
+        Bun::V::validateInteger(scope, globalObject, user, "user"_s, jsNumber(0), jsNumber(std::pow(2, 31) - 1), &uid);
+        RETURN_IF_EXCEPTION(scope, {});
+        if (getpwuid_r(uid, &pwd, buf, sizeof(buf), &pp) != 0 || pp == nullptr) {
+            auto message = makeString("User identifier does not exist: "_s, String::number(uid));
+            scope.throwException(globalObject, createError(globalObject, ErrorCode::ERR_UNKNOWN_CREDENTIAL, message));
+            return {};
+        }
+        username = pp->pw_name;
+    } else {
+        auto userString = user.toWTFString(globalObject);
+        RETURN_IF_EXCEPTION(scope, {});
+        auto utf8 = userString.utf8();
+        username = utf8.data();
+    }
+
+    int result = initgroups(username, gid);
+    if (result != 0) {
+        throwSystemError(scope, globalObject, "initgroups"_s, errno);
+        return {};
+    }
+
+    return JSValue::encode(jsNumber(result));
+}
+
 #endif
 
 JSC_DEFINE_HOST_FUNCTION(Process_functionAssert, (JSGlobalObject * globalObject, CallFrame* callFrame))
@@ -3658,7 +3711,7 @@ extern "C" void Process__emitErrorEvent(Zig::GlobalObject* global, EncodedJSValu
   version                          constructVersion                                    PropertyCallback
   versions                         constructVersions                                   PropertyCallback
 
-#if !OS(WINDOWS)
+#if OS(DARWIN) || OS(LINUX)
   getegid                          Process_functiongetegid                             Function 0
   geteuid                          Process_functiongeteuid                             Function 0
   getgid                           Process_functiongetgid                              Function 0
@@ -3669,6 +3722,7 @@ extern "C" void Process__emitErrorEvent(Zig::GlobalObject* global, EncodedJSValu
   seteuid                          Process_functionseteuid                             Function 1
   setgid                           Process_functionsetgid                              Function 1
   setgroups                        Process_functionsetgroups                           Function 1
+  initgroups                       Process_functioninitgroups                               Function 2
   setuid                           Process_functionsetuid                              Function 1
 #endif
 @end

test/js/node/test/parallel/test-process-initgroups.js

@@ -0,0 +1,60 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+if (common.isWindows) {
+  assert.strictEqual(process.initgroups, undefined);
+  return;
+}
+
+const { isMainThread } = require('worker_threads');
+
+if (!isMainThread) {
+  return;
+}
+
+[undefined, null, true, {}, [], () => {}].forEach((val) => {
+  assert.throws(
+    () => {
+      process.initgroups(val);
+    },
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError',
+      message:
+        'The "user" argument must be ' +
+        'one of type number or string.' +
+        common.invalidArgTypeHelper(val)
+    }
+  );
+});
+
+[undefined, null, true, {}, [], () => {}].forEach((val) => {
+  assert.throws(
+    () => {
+      process.initgroups('foo', val);
+    },
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError',
+      message:
+        'The "extraGroup" argument must be ' +
+        'one of type number or string.' +
+        common.invalidArgTypeHelper(val)
+    }
+  );
+});
+
+assert.throws(
+  () => {
+    process.initgroups(
+      'fhqwhgadshgnsdhjsdbkhsdabkfabkveyb',
+      'fhqwhgadshgnsdhjsdbkhsdabkfabkveyb'
+    );
+  },
+  {
+    code: 'ERR_UNKNOWN_CREDENTIAL',
+    message:
+      'Group identifier does not exist: fhqwhgadshgnsdhjsdbkhsdabkfabkveyb'
+  }
+);