Add synthetic buffer module (#1076)

* Add synthetic buffer module

* rename Buffer.h to BufferModule.h

4 files changed, 44 insertions, 21 deletions

diff --git a/Makefile b/Makefile
index 42989bbb4..4aca77426 100644
--- a/Makefile
+++ b/Makefile
@@ -266,6 +266,7 @@ MAC_INCLUDE_DIRS := -I$(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders \
 		-Isrc/bun.js/bindings/webcore \
 		-Isrc/bun.js/bindings/sqlite \
 		-Isrc/bun.js/builtins/cpp \
+		-Isrc/bun.js/modules \
 		-I$(WEBKIT_DIR)/Source/bmalloc  \
 		-I$(WEBKIT_DIR)/Source \
 		-I$(JSC_INCLUDE_DIR)
@@ -276,6 +277,7 @@ LINUX_INCLUDE_DIRS := -I$(JSC_INCLUDE_DIR) \
 					  -Isrc/bun.js/bindings/webcore \
 					  -Isrc/bun.js/bindings/sqlite \
 					  -Isrc/bun.js/builtins/cpp \
+						-Isrc/bun.js/modules \
 					  -I$(ZLIB_INCLUDE_DIR)
 
 
@@ -1115,6 +1117,7 @@ jsc-copy-headers:
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/runtime/LazyPropertyInlines.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/LazyPropertyInlines.h
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/runtime/JSTypedArrayViewPrototype.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/JSTypedArrayViewPrototype.h
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/runtime/JSTypedArrayPrototypes.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/JSTypedArrayPrototypes.h
+	cp $(WEBKIT_DIR)/Source/JavaScriptCore/runtime/JSModuleNamespaceObject.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/JSModuleNamespaceObject.h
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/jit/JIT.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/JIT.h
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/bytecode/StructureStubInfo.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/StructureStubInfo.h
 	cp $(WEBKIT_DIR)/Source/JavaScriptCore/bytecode/PolymorphicAccess.h $(WEBKIT_RELEASE_DIR)/JavaScriptCore/PrivateHeaders/JavaScriptCore/PolymorphicAccess.h
diff --git a/src/bun.js/bindings/ZigGlobalObject.cpp b/src/bun.js/bindings/ZigGlobalObject.cpp
index 54f79af54..52c25d545 100644
--- a/src/bun.js/bindings/ZigGlobalObject.cpp
+++ b/src/bun.js/bindings/ZigGlobalObject.cpp
@@ -37,6 +37,7 @@
 #include "JavaScriptCore/JSLock.h"
 #include "JavaScriptCore/JSMap.h"
 #include "JavaScriptCore/JSModuleLoader.h"
+#include "JavaScriptCore/JSModuleNamespaceObject.h"
 #include "JavaScriptCore/JSModuleRecord.h"
 #include "JavaScriptCore/JSNativeStdFunction.h"
 #include "JavaScriptCore/JSObject.h"
@@ -149,6 +150,8 @@ using JSBuffer = WebCore::JSBuffer;
 #include "DOMJITHelpers.h"
 #include <JavaScriptCore/DFGAbstractHeap.h>
 
+#include "../modules/BufferModule.h"
+
 // #include <iostream>
 static bool has_loaded_jsc = false;
 
@@ -1761,6 +1764,12 @@ void GlobalObject::finishCreation(VM& vm)
     Base::finishCreation(vm);
     ASSERT(inherits(info()));
 
+    // Change prototype from null to object for synthetic modules.
+    m_moduleNamespaceObjectStructure.initLater(
+        [] (const Initializer<Structure>& init) {
+            init.set(JSModuleNamespaceObject::createStructure(init.vm, init.owner, init.owner->objectPrototype()));
+        });
+
     m_NapiClassStructure.initLater(
         [](LazyClassStructure::Initializer& init) {
             init.setStructure(Zig::NapiClass::createStructure(init.vm, init.global, init.global->functionPrototype()));
@@ -2461,20 +2470,9 @@ static JSC_DEFINE_HOST_FUNCTION(functionFulfillModuleSync,
     }
 
     if (res.result.value.tag == SyntheticModuleType::Buffer) {
-        auto generateSource = [](JSC::JSGlobalObject* lexicalGlobalObject, JSC::Identifier moduleKey, Vector<JSC::Identifier, 4>& exportNames, JSC::MarkedArgumentBuffer& exportValues) {
-            JSC::VM& vm = lexicalGlobalObject->vm();
-            GlobalObject* globalObject = reinterpret_cast<GlobalObject*>(lexicalGlobalObject);
-
-            exportNames.append(JSC::Identifier::fromString(vm, "Buffer"_s));
-            exportValues.append(WebCore::JSBuffer::getConstructor(vm, globalObject));
-
-            exportNames.append(JSC::Identifier::fromString(vm, "Blob"_s));
-            exportValues.append(globalObject->getDirect(vm, JSC::Identifier::fromString(vm, "Blob"_s)));
-        };
-
         auto source = JSC::SourceCode(
             JSC::SyntheticSourceProvider::create(
-                WTFMove(generateSource),
+                generateBufferSourceCode,
                 JSC::SourceOrigin(WTF::URL::fileURLWithFileSystemPath("node:buffer"_s)), WTFMove(moduleKey)));
 
         globalObject->moduleLoader()->provideFetch(globalObject, key, WTFMove(source));
@@ -2538,16 +2536,9 @@ JSC::JSInternalPromise* GlobalObject::moduleLoaderFetch(JSGlobalObject* globalOb
 
         globalObject->vm().drainMicrotasks();
         return promise;
-    } else if (res.result.value.tag == 1024) {
-        auto generateSource = [](JSC::JSGlobalObject* lexicalGlobalObject, JSC::Identifier moduleKey, Vector<JSC::Identifier, 4>& exportNames, JSC::MarkedArgumentBuffer& exportValues) {
-            JSC::VM& vm = lexicalGlobalObject->vm();
-            GlobalObject* globalObject = reinterpret_cast<GlobalObject*>(lexicalGlobalObject);
-            exportNames.append(JSC::Identifier::fromString(globalObject->vm(), "Buffer"_s));
-            exportValues.append(WebCore::JSBuffer::getConstructor(vm, globalObject));
-        };
-
+    } else if (res.result.value.tag == SyntheticModuleType::Buffer) {
         auto source = JSC::SourceCode(
-            JSC::SyntheticSourceProvider::create(WTFMove(generateSource),
+            JSC::SyntheticSourceProvider::create(generateBufferSourceCode,
                 JSC::SourceOrigin(), WTFMove(moduleKey)));
 
         auto sourceCode = JSSourceCode::create(vm, WTFMove(source));
diff --git a/src/bun.js/javascript.zig b/src/bun.js/javascript.zig
index 71394bfbf..d480bbac4 100644
--- a/src/bun.js/javascript.zig
+++ b/src/bun.js/javascript.zig
@@ -2759,6 +2759,7 @@ pub const HardcodedModule = enum {
     pub const Map = bun.ComptimeStringMap(
         HardcodedModule,
         .{
+            .{ "buffer", HardcodedModule.@"node:buffer" },
             .{ "bun:ffi", HardcodedModule.@"bun:ffi" },
             .{ "bun:jsc", HardcodedModule.@"bun:jsc" },
             .{ "bun:main", HardcodedModule.@"bun:main" },
@@ -2791,6 +2792,7 @@ pub const HardcodedModule = enum {
     pub const LinkerMap = bun.ComptimeStringMap(
         string,
         .{
+            .{ "buffer", "node:buffer" },
             .{ "bun", "bun" },
             .{ "bun:ffi", "bun:ffi" },
             .{ "bun:jsc", "bun:jsc" },
diff --git a/src/bun.js/modules/BufferModule.h b/src/bun.js/modules/BufferModule.h
new file mode 100644
index 000000000..12d4c54c8
--- /dev/null
+++ b/src/bun.js/modules/BufferModule.h
@@ -0,0 +1,27 @@
+#include "../bindings/ZigGlobalObject.h"
+#include "JavaScriptCore/JSGlobalObject.h"
+
+namespace Zig {
+
+inline void generateBufferSourceCode(JSC::JSGlobalObject* lexicalGlobalObject, JSC::Identifier moduleKey, Vector<JSC::Identifier, 4>& exportNames, JSC::MarkedArgumentBuffer& exportValues) {
+    JSC::VM& vm = lexicalGlobalObject->vm();
+    GlobalObject* globalObject = reinterpret_cast<GlobalObject*>(lexicalGlobalObject);
+
+    exportNames.append(JSC::Identifier::fromString(vm, "Buffer"_s));
+    exportValues.append(WebCore::JSBuffer::getConstructor(vm, globalObject));
+
+    // substitute after JSBlob is implemented.
+    exportNames.append(JSC::Identifier::fromString(vm, "Blob"_s));
+    exportValues.append(JSC::jsUndefined());
+
+    exportNames.append(JSC::Identifier::fromString(vm, "INSPECT_MAX_BYTES"_s));
+    exportValues.append(JSC::jsNumber(50));
+
+    exportNames.append(JSC::Identifier::fromString(vm, "kMaxLength"_s));
+    exportValues.append(JSC::jsNumber(4294967296LL));
+
+    exportNames.append(JSC::Identifier::fromString(vm, "kMaxLength"_s));
+    exportValues.append(JSC::jsNumber(536870888));
+}
+
+}