Support async `onLoad` callbacks in `Bun.plugin`

1 files changed, 94 insertions, 0 deletions

diff --git a/src/bun.js/bindings/ModuleLoader.h b/src/bun.js/bindings/ModuleLoader.h
new file mode 100644
index 000000000..98f8b7dbb
--- /dev/null
+++ b/src/bun.js/bindings/ModuleLoader.h
@@ -0,0 +1,94 @@
+#include "root.h"
+#include "headers-handwritten.h"
+
+#include "JavaScriptCore/JSCInlines.h"
+#include "BunClientData.h"
+
+namespace Zig {
+class GlobalObject;
+}
+
+namespace JSC {
+class JSInternalPromise;
+}
+
+namespace Bun {
+using namespace JSC;
+
+typedef uint8_t OnLoadResultType;
+const OnLoadResultType OnLoadResultTypeError = 0;
+const OnLoadResultType OnLoadResultTypeCode = 1;
+const OnLoadResultType OnLoadResultTypeObject = 2;
+const OnLoadResultType OnLoadResultTypePromise = 3;
+
+struct CodeString {
+    ZigString string;
+    JSC::JSValue value;
+    BunLoaderType loader;
+};
+
+union OnLoadResultValue {
+    CodeString sourceText;
+    JSC::JSValue object;
+    JSC::JSValue promise;
+    JSC::JSValue error;
+};
+
+struct OnLoadResult {
+    OnLoadResultValue value;
+    OnLoadResultType type;
+};
+
+class PendingVirtualModuleResult : public JSC::JSInternalFieldObjectImpl<3> {
+public:
+    using Base = JSC::JSInternalFieldObjectImpl<3>;
+
+    template<typename, JSC::SubspaceAccess mode> static JSC::GCClient::IsoSubspace* subspaceFor(JSC::VM& vm)
+    {
+        if constexpr (mode == JSC::SubspaceAccess::Concurrently)
+            return nullptr;
+        return WebCore::subspaceForImpl<PendingVirtualModuleResult, WebCore::UseCustomHeapCellType::No>(
+            vm,
+            [](auto& spaces) { return spaces.m_clientSubspaceForPendingVirtualModuleResult.get(); },
+            [](auto& spaces, auto&& space) { spaces.m_clientSubspaceForPendingVirtualModuleResult = WTFMove(space); },
+            [](auto& spaces) { return spaces.m_subspaceForPendingVirtualModuleResult.get(); },
+            [](auto& spaces, auto&& space) { spaces.m_subspaceForPendingVirtualModuleResult = WTFMove(space); });
+    }
+
+    JS_EXPORT_PRIVATE static PendingVirtualModuleResult* create(VM&, Structure*);
+    static PendingVirtualModuleResult* create(JSC::JSGlobalObject* globalObject, const WTF::String& specifier, const WTF::String& referrer);
+    static PendingVirtualModuleResult* createWithInitialValues(VM&, Structure*);
+    static Structure* createStructure(VM&, JSGlobalObject*, JSValue);
+
+    JSC::JSInternalPromise* internalPromise();
+
+    static std::array<JSValue, numberOfInternalFields> initialValues()
+    {
+        return { {
+            jsUndefined(),
+            jsUndefined(),
+            jsUndefined(),
+        } };
+    }
+
+    DECLARE_EXPORT_INFO;
+    DECLARE_VISIT_CHILDREN;
+
+    PendingVirtualModuleResult(JSC::VM&, JSC::Structure*);
+    void finishCreation(JSC::VM&, const WTF::String& specifier, const WTF::String& referrer);
+};
+
+OnLoadResult handleOnLoadResultNotPromise(Zig::GlobalObject* globalObject, JSC::JSValue objectValue);
+JSValue fetchSourceCodeSync(
+    Zig::GlobalObject* globalObject,
+    ErrorableResolvedSource* res,
+    ZigString* specifier,
+    ZigString* referrer);
+
+JSValue fetchSourceCodeAsync(
+    Zig::GlobalObject* globalObject,
+    ErrorableResolvedSource* res,
+    ZigString* specifier,
+    ZigString* referrer);
+
+} // namespace Bun
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