Fixes #4588 (#4804)

* Fixes #4588

* typo

* fixup

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

2 files changed, 18 insertions, 1 deletions

diff --git a/src/bun.js/bindings/ZigGlobalObject.cpp b/src/bun.js/bindings/ZigGlobalObject.cpp
index 6398fb7a0..cdc4adb1b 100644
--- a/src/bun.js/bindings/ZigGlobalObject.cpp
+++ b/src/bun.js/bindings/ZigGlobalObject.cpp
@@ -3075,11 +3075,21 @@ void GlobalObject::finishCreation(VM& vm)
             JSC::Identifier userAgentIdentifier = JSC::Identifier::fromString(init.vm, "userAgent"_s);
             JSC::Identifier hardwareConcurrencyIdentifier = JSC::Identifier::fromString(init.vm, "hardwareConcurrency"_s);
 
-            JSC::JSObject* obj = JSC::constructEmptyObject(init.owner, init.owner->objectPrototype(), 3);
+            JSC::JSObject* obj = JSC::constructEmptyObject(init.owner, init.owner->objectPrototype(), 4);
             obj->putDirect(init.vm, userAgentIdentifier, JSC::jsString(init.vm, str));
             obj->putDirect(init.vm, init.vm.propertyNames->toStringTagSymbol,
                 jsNontrivialString(init.vm, "Navigator"_s), JSC::PropertyAttribute::DontEnum | JSC::PropertyAttribute::ReadOnly);
 
+// https://developer.mozilla.org/en-US/docs/Web/API/Navigator/platform
+// https://github.com/oven-sh/bun/issues/4588
+#if OS(DARWIN)
+            obj->putDirect(init.vm, JSC::Identifier::fromString(init.vm, "platform"_s), JSC::jsString(init.vm, String("MacIntel"_s)));
+#elif OS(WINDOWS)
+            obj->putDirect(init.vm, JSC::Identifier::fromString(init.vm, "platform"_s), JSC::jsString(init.vm, String("Win32"_s)));
+#elif OS(LINUX)
+            obj->putDirect(init.vm, JSC::Identifier::fromString(init.vm, "platform"_s), JSC::jsString(init.vm, String("Linux x86_64"_s)));
+#endif
+
             obj->putDirect(init.vm, hardwareConcurrencyIdentifier, JSC::jsNumber(cpuCount));
             init.set(
                 obj);
diff --git a/test/js/web/web-globals.test.js b/test/js/web/web-globals.test.js
index 9b4c86006..1a4d7b1d1 100644
--- a/test/js/web/web-globals.test.js
+++ b/test/js/web/web-globals.test.js
@@ -224,4 +224,11 @@ test("navigator", () => {
   const userAgent = `Bun/${version}`;
   expect(navigator.hardwareConcurrency > 0).toBe(true);
   expect(navigator.userAgent).toBe(userAgent);
+  if (process.platform === "darwin") {
+    expect(navigator.platform).toBe("MacIntel");
+  } else if (process.platform === "win32") {
+    expect(navigator.platform).toBe("Win32");
+  } else if (process.platform === "linux") {
+    expect(navigator.platform).toBe("Linux x86_64");
+  }
 });