Support overriding ESM exports for already loaded modules

oven-sh · Oct 24, 2023 · 00ae02e · 00ae02e
1 parent 60344b4
commit 00ae02e
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Showing 2 changed files with 75 additions and 2 deletions.
diff --git a/Source/JavaScriptCore/runtime/JSModuleNamespaceObject.cpp b/Source/JavaScriptCore/runtime/JSModuleNamespaceObject.cpp
@@ -29,6 +29,7 @@
 #include "AbstractModuleRecord.h"
 #include "JSCInlines.h"
 #include "JSModuleEnvironment.h"
+#include "JSModuleRecord.h"
 
 namespace JSC {
 
@@ -53,7 +54,7 @@ void JSModuleNamespaceObject::finishCreation(JSGlobalObject* globalObject, Abstr
     //     The list is ordered as if an Array of those String values had been sorted using Array.prototype.sort using SortCompare as comparator.
     //
     // Sort the exported names by the code point order.
-    std::sort(resolutions.begin(), resolutions.end(), [] (const auto& lhs, const auto& rhs) {
+    std::sort(resolutions.begin(), resolutions.end(), [](const auto& lhs, const auto& rhs) {
         return codePointCompare(lhs.first.impl(), rhs.first.impl()) < 0;
     });
 
@@ -191,11 +192,18 @@ bool JSModuleNamespaceObject::getOwnPropertySlotByIndex(JSObject* cell, JSGlobal
     return thisObject->getOwnPropertySlotCommon(globalObject, Identifier::from(vm, propertyName), slot);
 }
 
-bool JSModuleNamespaceObject::put(JSCell*, JSGlobalObject* globalObject, PropertyName, JSValue, PutPropertySlot& slot)
+bool JSModuleNamespaceObject::put(JSCell* cell, JSGlobalObject* globalObject, PropertyName, JSValue, PutPropertySlot& slot)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
+#if USE(BUN_JSC_ADDITIONS)
+    auto* thisObject = jsCast<JSModuleNamespaceObject*>(cell);
+    if (thisObject->m_isOverridingValue) {
+        return true;
+    }
+#endif
+
     // http://www.ecma-international.org/ecma-262/6.0/#sec-module-namespace-exotic-objects-set-p-v-receiver
     if (slot.isStrictMode())
         throwTypeError(globalObject, scope, ReadonlyPropertyWriteError);
@@ -269,6 +277,12 @@ bool JSModuleNamespaceObject::defineOwnProperty(JSObject* cell, JSGlobalObject*
     bool isCurrentDefined = thisObject->getOwnPropertyDescriptor(globalObject, propertyName, current);
     RETURN_IF_EXCEPTION(scope, false);
 
+#if USE(BUN_JSC_ADDITIONS)
+    if (thisObject->m_isOverridingValue) {
+        return true;
+    }
+#endif
+
     // 3. If current is undefined, return false.
     if (!isCurrentDefined) {
         if (shouldThrow)
@@ -319,4 +333,55 @@ bool JSModuleNamespaceObject::defineOwnProperty(JSObject* cell, JSGlobalObject*
     return true;
 }
 
+#if USE(BUN_JSC_ADDITIONS)
+
+void JSModuleNamespaceObject::overrideExports(JSGlobalObject* globalObject, const WTF::Function<bool(JSGlobalObject* globalObject, const Identifier& exportName, JSC::JSValue& result)>& iter)
+{
+    VM& vm = globalObject->vm();
+    auto scope = DECLARE_THROW_SCOPE(vm);
+
+    for (auto& pair : m_exports) {
+        JSValue value = jsUndefined();
+        const Identifier& name = pair.value.localName;
+
+        if (iter(globalObject, name, value)) {
+            auto* moduleNamespaceObject = pair.value.moduleRecord->getModuleNamespace(globalObject);
+            RETURN_IF_EXCEPTION(scope, void());
+            auto* moduleEnvironment = pair.value.moduleRecord->moduleEnvironment();
+            bool putResult = false;
+            moduleNamespaceObject->m_isOverridingValue = true;
+            symbolTablePutTouchWatchpointSet(moduleEnvironment, globalObject, name, value, false, true, putResult);
+            JSC::PutPropertySlot putter = JSC::PutPropertySlot(moduleNamespaceObject, false);
+            moduleNamespaceObject->put(moduleNamespaceObject, globalObject, name, value, putter);
+            moduleNamespaceObject->m_isOverridingValue = false;
+        }
+    }
+}
+
+bool JSModuleNamespaceObject::overrideExportValue(JSGlobalObject* globalObject, PropertyName name, JSValue value)
+{
+    auto iterator = m_exports.find(name.uid());
+    if (iterator == m_exports.end())
+        return false;
+
+    auto& vm = globalObject->vm();
+    auto scope = DECLARE_THROW_SCOPE(vm);
+
+    ExportEntry& exportEntry = iterator->value;
+    auto* moduleNamespaceObject = exportEntry.moduleRecord->getModuleNamespace(globalObject);
+    RETURN_IF_EXCEPTION(scope, false);
+
+    JSModuleEnvironment* moduleEnvironment = exportEntry.moduleRecord->moduleEnvironment();
+
+    bool putResult = false;
+    moduleNamespaceObject->m_isOverridingValue = true;
+    symbolTablePutTouchWatchpointSet(moduleEnvironment, globalObject, name, value, false, true, putResult);
+    JSC::PutPropertySlot putter = JSC::PutPropertySlot(moduleNamespaceObject, false);
+    putResult = moduleNamespaceObject->put(moduleNamespaceObject, globalObject, name, value, putter);
+    moduleNamespaceObject->m_isOverridingValue = false;
+    return putResult;
+}
+
+#endif
+
 } // namespace JSC
diff --git a/Source/JavaScriptCore/runtime/JSModuleNamespaceObject.h b/Source/JavaScriptCore/runtime/JSModuleNamespaceObject.h
@@ -64,6 +64,11 @@ class JSModuleNamespaceObject final : public JSNonFinalObject {
 
     DECLARE_EXPORT_INFO;
 
+#if USE(BUN_JSC_ADDITIONS)
+    bool overrideExportValue(JSGlobalObject*, PropertyName, JSValue);
+    void overrideExports(JSGlobalObject* globalObject, const WTF::Function<bool(JSGlobalObject* globalObject, const Identifier& exportName, JSC::JSValue &result)>& iter);
+#endif
+
     inline static Structure* createStructure(VM&, JSGlobalObject*, JSValue);
 
     AbstractModuleRecord* moduleRecord() { return m_moduleRecord.get(); }
@@ -84,6 +89,9 @@ class JSModuleNamespaceObject final : public JSNonFinalObject {
     ExportMap m_exports;
     FixedVector<Identifier> m_names;
     WriteBarrier<AbstractModuleRecord> m_moduleRecord;
+#if USE(BUN_JSC_ADDITIONS)
+    bool m_isOverridingValue = false;
+#endif
 
     friend size_t cellSize(JSCell*);
 };