feat(node:fs): add `cp`/`cpSync`/`promises.cp` + async `copyFile` (#4340)

* half working disaster code

* this

* async copyFile

* .

* its failing symlink tests

* asdfg

* asdf

* hmm

* okay i think ti works

* small edits

* fix test on linux

* i hate atomics / atomics hate me back <3

* add a message in the builtins bundler that 0.8 is needed. it breaks on older versions lol.

* fixed

* rebase

1 files changed, 64 insertions, 0 deletions

diff --git a/src/bun.js/bindings/ZigGeneratedClasses.cpp b/src/bun.js/bindings/ZigGeneratedClasses.cpp
index 497408632..523735c7b 100644
--- a/src/bun.js/bindings/ZigGeneratedClasses.cpp
+++ b/src/bun.js/bindings/ZigGeneratedClasses.cpp
@@ -13992,6 +13992,12 @@ JSC_DECLARE_HOST_FUNCTION(NodeJSFSPrototype__copyFileCallback);
 extern "C" EncodedJSValue NodeJSFSPrototype__copyFileSync(void* ptr, JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame);
 JSC_DECLARE_HOST_FUNCTION(NodeJSFSPrototype__copyFileSyncCallback);
 
+extern "C" EncodedJSValue NodeJSFSPrototype__cp(void* ptr, JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame);
+JSC_DECLARE_HOST_FUNCTION(NodeJSFSPrototype__cpCallback);
+
+extern "C" EncodedJSValue NodeJSFSPrototype__cpSync(void* ptr, JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame);
+JSC_DECLARE_HOST_FUNCTION(NodeJSFSPrototype__cpSyncCallback);
+
 extern "C" JSC::EncodedJSValue NodeJSFSPrototype__getDirent(void* ptr, JSC::JSGlobalObject* lexicalGlobalObject);
 JSC_DECLARE_CUSTOM_GETTER(NodeJSFSPrototype__DirentGetterWrap);
 
@@ -14220,6 +14226,8 @@ static const HashTableValue JSNodeJSFSPrototypeTableValues[] = {
     { "closeSync"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__closeSyncCallback, 1 } },
     { "copyFile"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__copyFileCallback, 4 } },
     { "copyFileSync"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__copyFileSyncCallback, 3 } },
+    { "cp"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__cpCallback, 2 } },
+    { "cpSync"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__cpSyncCallback, 2 } },
     { "Dirent"_s, static_cast<unsigned>(JSC::PropertyAttribute::ReadOnly | JSC::PropertyAttribute::CustomAccessor | JSC::PropertyAttribute::DOMAttribute | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::GetterSetterType, NodeJSFSPrototype__DirentGetterWrap, 0 } },
     { "exists"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__existsCallback, 2 } },
     { "existsSync"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function | PropertyAttribute::DontDelete), NoIntrinsic, { HashTableValue::NativeFunctionType, NodeJSFSPrototype__existsSyncCallback, 1 } },
@@ -14643,6 +14651,62 @@ JSC_DEFINE_HOST_FUNCTION(NodeJSFSPrototype__copyFileSyncCallback, (JSGlobalObjec
     return NodeJSFSPrototype__copyFileSync(thisObject->wrapped(), lexicalGlobalObject, callFrame);
 }
 
+JSC_DEFINE_HOST_FUNCTION(NodeJSFSPrototype__cpCallback, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto& vm = lexicalGlobalObject->vm();
+
+    JSNodeJSFS* thisObject = jsDynamicCast<JSNodeJSFS*>(callFrame->thisValue());
+
+    if (UNLIKELY(!thisObject)) {
+        auto throwScope = DECLARE_THROW_SCOPE(vm);
+        throwVMTypeError(lexicalGlobalObject, throwScope, "Expected 'this' to be instanceof NodeJSFS"_s);
+        return JSValue::encode({});
+    }
+
+    JSC::EnsureStillAliveScope thisArg = JSC::EnsureStillAliveScope(thisObject);
+
+#ifdef BUN_DEBUG
+    /** View the file name of the JS file that called this function
+     * from a debugger */
+    SourceOrigin sourceOrigin = callFrame->callerSourceOrigin(vm);
+    const char* fileName = sourceOrigin.string().utf8().data();
+    static const char* lastFileName = nullptr;
+    if (lastFileName != fileName) {
+        lastFileName = fileName;
+    }
+#endif
+
+    return NodeJSFSPrototype__cp(thisObject->wrapped(), lexicalGlobalObject, callFrame);
+}
+
+JSC_DEFINE_HOST_FUNCTION(NodeJSFSPrototype__cpSyncCallback, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto& vm = lexicalGlobalObject->vm();
+
+    JSNodeJSFS* thisObject = jsDynamicCast<JSNodeJSFS*>(callFrame->thisValue());
+
+    if (UNLIKELY(!thisObject)) {
+        auto throwScope = DECLARE_THROW_SCOPE(vm);
+        throwVMTypeError(lexicalGlobalObject, throwScope, "Expected 'this' to be instanceof NodeJSFS"_s);
+        return JSValue::encode({});
+    }
+
+    JSC::EnsureStillAliveScope thisArg = JSC::EnsureStillAliveScope(thisObject);
+
+#ifdef BUN_DEBUG
+    /** View the file name of the JS file that called this function
+     * from a debugger */
+    SourceOrigin sourceOrigin = callFrame->callerSourceOrigin(vm);
+    const char* fileName = sourceOrigin.string().utf8().data();
+    static const char* lastFileName = nullptr;
+    if (lastFileName != fileName) {
+        lastFileName = fileName;
+    }
+#endif
+
+    return NodeJSFSPrototype__cpSync(thisObject->wrapped(), lexicalGlobalObject, callFrame);
+}
+
 JSC_DEFINE_CUSTOM_GETTER(NodeJSFSPrototype__DirentGetterWrap, (JSGlobalObject * lexicalGlobalObject, EncodedJSValue thisValue, PropertyName attributeName))
 {
     auto& vm = lexicalGlobalObject->vm();