Add missing `buffer` module exports

2 files changed, 101 insertions, 15 deletions

diff --git a/src/bun.js/modules/BufferModule.h b/src/bun.js/modules/BufferModule.h
index afc00ffd1..42eab5173 100644
--- a/src/bun.js/modules/BufferModule.h
+++ b/src/bun.js/modules/BufferModule.h
@@ -1,9 +1,22 @@
 #include "../bindings/JSBuffer.h"
 #include "../bindings/ZigGlobalObject.h"
 #include "JavaScriptCore/JSGlobalObject.h"
+#include "JavaScriptCore/ObjectConstructor.h"
 
 namespace Zig {
 using namespace WebCore;
+using namespace JSC;
+
+JSC_DEFINE_HOST_FUNCTION(jsFunctionNotImplemented,
+                         (JSGlobalObject * globalObject,
+                          CallFrame *callFrame)) {
+  VM &vm = globalObject->vm();
+  auto scope = DECLARE_THROW_SCOPE(vm);
+
+  throwException(globalObject, scope,
+                 createError(globalObject, "Not implemented"_s));
+  return JSValue::encode(jsUndefined());
+}
 
 inline void generateBufferSourceCode(JSC::JSGlobalObject *lexicalGlobalObject,
                                      JSC::Identifier moduleKey,
@@ -13,8 +26,22 @@ inline void generateBufferSourceCode(JSC::JSGlobalObject *lexicalGlobalObject,
   GlobalObject *globalObject =
       reinterpret_cast<GlobalObject *>(lexicalGlobalObject);
 
-  exportNames.append(JSC::Identifier::fromString(vm, "Buffer"_s));
-  exportValues.append(globalObject->JSBufferConstructor());
+  JSC::JSObject *defaultObject = JSC::constructEmptyObject(
+      globalObject, globalObject->objectPrototype(), 12);
+
+  defaultObject->putDirect(vm,
+                           PropertyName(Identifier::fromUid(
+                               vm.symbolRegistry().symbolForKey("CommonJS"_s))),
+                           jsNumber(0), 0);
+
+  auto exportProperty = [&](JSC::Identifier name, JSC::JSValue value) {
+    exportNames.append(name);
+    exportValues.append(value);
+    defaultObject->putDirect(vm, name, value, 0);
+  };
+
+  exportProperty(JSC::Identifier::fromString(vm, "Buffer"_s),
+                 globalObject->JSBufferConstructor());
 
   auto *slowBuffer = JSC::JSFunction::create(
       vm, globalObject, 0, "SlowBuffer"_s, WebCore::constructSlowBuffer,
@@ -24,21 +51,60 @@ inline void generateBufferSourceCode(JSC::JSGlobalObject *lexicalGlobalObject,
       vm, vm.propertyNames->prototype, globalObject->JSBufferPrototype(),
       JSC::PropertyAttribute::ReadOnly | JSC::PropertyAttribute::DontEnum |
           JSC::PropertyAttribute::DontDelete);
-  exportNames.append(JSC::Identifier::fromString(vm, "SlowBuffer"_s));
-  exportValues.append(slowBuffer);
+  exportProperty(JSC::Identifier::fromString(vm, "SlowBuffer"_s), slowBuffer);
+  auto blobIdent = JSC::Identifier::fromString(vm, "Blob"_s);
+
+  JSValue blobValue =
+      lexicalGlobalObject->get(globalObject, PropertyName(blobIdent));
+  exportProperty(blobIdent, blobValue);
+
+  // TODO: implement File
+  exportProperty(JSC::Identifier::fromString(vm, "File"_s), blobValue);
+
+  exportProperty(JSC::Identifier::fromString(vm, "INSPECT_MAX_BYTES"_s),
+                 JSC::jsNumber(50));
+
+  exportProperty(JSC::Identifier::fromString(vm, "kMaxLength"_s),
+                 JSC::jsNumber(4294967296LL));
+
+  exportProperty(JSC::Identifier::fromString(vm, "kStringMaxLength"_s),
+                 JSC::jsNumber(536870888));
+
+  JSC::JSObject *constants = JSC::constructEmptyObject(
+      lexicalGlobalObject, globalObject->objectPrototype(), 2);
+  constants->putDirect(vm, JSC::Identifier::fromString(vm, "MAX_LENGTH"_s),
+                       JSC::jsNumber(4294967296LL));
+  constants->putDirect(vm,
+                       JSC::Identifier::fromString(vm, "MAX_STRING_LENGTH"_s),
+                       JSC::jsNumber(536870888));
+
+  exportProperty(JSC::Identifier::fromString(vm, "constants"_s), constants);
+
+  JSC::Identifier atobI = JSC::Identifier::fromString(vm, "atob"_s);
+  JSC::JSValue atobV =
+      lexicalGlobalObject->get(globalObject, PropertyName(atobI));
+
+  JSC::Identifier btoaI = JSC::Identifier::fromString(vm, "btoa"_s);
+  JSC::JSValue btoaV =
+      lexicalGlobalObject->get(globalObject, PropertyName(btoaI));
+
+  exportProperty(atobI, atobV);
+  exportProperty(btoaI, btoaV);
+
+  auto *transcode = InternalFunction::createFunctionThatMasqueradesAsUndefined(
+      vm, globalObject, 1, "transcode"_s, jsFunctionNotImplemented);
 
-  exportNames.append(JSC::Identifier::fromString(vm, "Blob"_s));
-  exportValues.append(lexicalGlobalObject->get(
-      globalObject, PropertyName(Identifier::fromString(vm, "Blob"_s))));
+  exportProperty(JSC::Identifier::fromString(vm, "transcode"_s), transcode);
 
-  exportNames.append(JSC::Identifier::fromString(vm, "INSPECT_MAX_BYTES"_s));
-  exportValues.append(JSC::jsNumber(50));
+  auto *resolveObjectURL =
+      InternalFunction::createFunctionThatMasqueradesAsUndefined(
+          vm, globalObject, 1, "resolveObjectURL"_s, jsFunctionNotImplemented);
 
-  exportNames.append(JSC::Identifier::fromString(vm, "kMaxLength"_s));
-  exportValues.append(JSC::jsNumber(4294967296LL));
+  exportProperty(JSC::Identifier::fromString(vm, "resolveObjectURL"_s),
+                 resolveObjectURL);
 
-  exportNames.append(JSC::Identifier::fromString(vm, "kMaxLength"_s));
-  exportValues.append(JSC::jsNumber(536870888));
+  exportNames.append(vm.propertyNames->defaultKeyword);
+  exportValues.append(defaultObject);
 }
 
 } // namespace Zig
diff --git a/test/bun.js/buffer.test.js b/test/bun.js/buffer.test.js
index d263a80eb..64c6cc41f 100644
--- a/test/bun.js/buffer.test.js
+++ b/test/bun.js/buffer.test.js
@@ -1,6 +1,8 @@
 import { describe, it, expect, beforeEach, afterEach } from "bun:test";
 import { gc } from "./gc";
 
+const BufferModule = await import("buffer");
+
 beforeEach(() => gc());
 afterEach(() => gc());
 
@@ -560,7 +562,7 @@ it("Buffer.swap16", () => {
   const examples = [
     ["", ""],
     ["a1", "1a"],
-    ["a1b2", "1a2b"]
+    ["a1b2", "1a2b"],
   ];
 
   for (let i = 0; i < examples.length; i++) {
@@ -586,7 +588,7 @@ it("Buffer.swap32", () => {
   const examples = [
     ["", ""],
     ["a1b2", "2b1a"],
-    ["a1b2c3d4", "2b1a4d3c"]
+    ["a1b2c3d4", "2b1a4d3c"],
   ];
 
   for (let i = 0; i < examples.length; i++) {
@@ -698,3 +700,21 @@ it("Buffer can be mocked", () => {
     buf.writeBigUInt64LE(0);
   }).not.toThrow();
 });
+
+it("constants", () => {
+  expect(BufferModule.constants.MAX_LENGTH).toBe(4294967296);
+  expect(BufferModule.constants.MAX_STRING_LENGTH).toBe(536870888);
+  expect(BufferModule.default.constants.MAX_LENGTH).toBe(4294967296);
+  expect(BufferModule.default.constants.MAX_STRING_LENGTH).toBe(536870888);
+});
+
+it("File", () => {
+  expect(BufferModule.File).toBe(Blob);
+});
+
+it("transcode", () => {
+  expect(typeof BufferModule.transcode).toBe("undefined");
+
+  // This is a masqueradesAsUndefined function
+  expect(() => BufferModule.transcode()).toThrow("Not implemented");
+});