ets2panda/checker/ETSAnalyzerHelpers.cpp

/*
 * Copyright (c) 2021-2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "ETSAnalyzerHelpers.h"
#include "checker/types/ets/etsAsyncFuncReturnType.h"

namespace ark::es2panda::checker {
void CheckExtensionIsShadowedInCurrentClassOrInterface(checker::ETSChecker *checker, checker::ETSObjectType *objType,
                                                       ir::ScriptFunction *extensionFunc, checker::Signature *signature)
{
    const auto methodName = extensionFunc->Id()->Name();
    // Only check if there are class and interfaces' instance methods which would shadow instance extension method
    auto *const variable = objType->GetOwnProperty<checker::PropertyType::INSTANCE_METHOD>(methodName);
    if (variable == nullptr) {
        return;
    }

    const auto *const funcType = variable->TsType()->AsETSFunctionType();
    for (auto *funcSignature : funcType->CallSignatures()) {
        signature->SetReturnType(funcSignature->ReturnType());
        if (!checker->Relation()->IsCompatibleTo(signature, funcSignature)) {
            continue;
        }

        checker->ReportWarning({"extension is shadowed by a instance member function '", funcType->Name(),
                                funcSignature, "' in class ", objType->Name()},
                               extensionFunc->Body()->Start());
        return;
    }
}

void CheckExtensionIsShadowedByMethod(checker::ETSChecker *checker, checker::ETSObjectType *objType,
                                      ir::ScriptFunction *extensionFunc, checker::Signature *signature)
{
    if (objType == nullptr) {
        return;
    }

    CheckExtensionIsShadowedInCurrentClassOrInterface(checker, objType, extensionFunc, signature);

    for (auto *interface : objType->Interfaces()) {
        CheckExtensionIsShadowedByMethod(checker, interface, extensionFunc, signature);
    }

    CheckExtensionIsShadowedByMethod(checker, objType->SuperType(), extensionFunc, signature);
}

static void ReplaceThisInExtensionMethod(checker::ETSChecker *checker, ir::ScriptFunction *extensionFunc)
{
    ASSERT(!extensionFunc->Params().empty());
    ASSERT(extensionFunc->Params()[0]->AsETSParameterExpression()->Ident()->Name() ==
           varbinder::TypedBinder::MANDATORY_PARAM_THIS);
    auto thisVariable = extensionFunc->Params()[0]->Variable();
    extensionFunc->Body()->TransformChildrenRecursively(
        [=](ir::AstNode *ast) {
            if (ast->IsThisExpression()) {
                auto *thisParam = checker->Allocator()->New<ir::Identifier>(
                    varbinder::TypedBinder::MANDATORY_PARAM_THIS, checker->Allocator());
                thisParam->SetParent(ast->Parent());
                thisParam->SetVariable(thisVariable);
                return static_cast<ir::AstNode *>(thisParam);
            }
            return ast;
        },
        "replace-this-in-extension-method");
}

void CheckExtensionMethod(checker::ETSChecker *checker, ir::ScriptFunction *extensionFunc, ir::MethodDefinition *node)
{
    auto *const classType = checker->GetApparentType(extensionFunc->Signature()->Params()[0]->TsType());
    if (!classType->IsETSObjectType() ||
        (!classType->AsETSObjectType()->HasObjectFlag(checker::ETSObjectFlags::CLASS) &&
         !classType->AsETSObjectType()->HasObjectFlag(checker::ETSObjectFlags::INTERFACE))) {
        checker->ThrowTypeError("Extension function can only defined for class and interface type.", node->Start());
    }
    if (classType->Variable()->Declaration()->Node()->IsClassDefinition() &&
        !classType->Variable()->Declaration()->Node()->AsClassDefinition()->IsClassDefinitionChecked()) {
        classType->Variable()->Declaration()->Node()->Check(checker);
    }

    // NOTE(gogabr): should be done in a lowering
    ReplaceThisInExtensionMethod(checker, extensionFunc);

    checker::SignatureInfo *originalExtensionSigInfo = checker->Allocator()->New<checker::SignatureInfo>(
        extensionFunc->Signature()->GetSignatureInfo(), checker->Allocator());
    originalExtensionSigInfo->minArgCount -= 1;
    originalExtensionSigInfo->params.erase(originalExtensionSigInfo->params.begin());
    checker::Signature *originalExtensionSigature =
        checker->CreateSignature(originalExtensionSigInfo, extensionFunc->Signature()->ReturnType(), extensionFunc);

    CheckExtensionIsShadowedByMethod(checker, classType->AsETSObjectType(), extensionFunc, originalExtensionSigature);
}

void DoBodyTypeChecking(ETSChecker *checker, ir::MethodDefinition *node, ir::ScriptFunction *scriptFunc)
{
    if (scriptFunc->HasBody() && (node->IsNative() || node->IsAbstract() || node->IsDeclare())) {
        checker->ThrowTypeError("Native, Abstract and Declare methods cannot have body.", scriptFunc->Body()->Start());
    }

    if (!scriptFunc->IsAsyncFunc() && scriptFunc->HasBody() &&
        (!scriptFunc->IsExternal() || scriptFunc->IsExternalOverload())) {
        checker::ScopeContext scopeCtx(checker, scriptFunc->Scope());
        checker::SavedCheckerContext savedContext(checker, checker->Context().Status(),
                                                  checker->Context().ContainingClass());
        checker->Context().SetContainingSignature(checker->GetSignatureFromMethodDefinition(node));

        if (node->IsStatic() && !node->IsConstructor() &&
            !checker->Context().ContainingClass()->HasObjectFlag(checker::ETSObjectFlags::GLOBAL)) {
            checker->AddStatus(checker::CheckerStatus::IN_STATIC_CONTEXT);
        }

        if (node->IsConstructor()) {
            checker->AddStatus(checker::CheckerStatus::IN_CONSTRUCTOR);
        }

        if (node->IsExtensionMethod()) {
            CheckExtensionMethod(checker, scriptFunc, node);
        }

        scriptFunc->Body()->Check(checker);

        if (scriptFunc->ReturnTypeAnnotation() == nullptr) {
            if (scriptFunc->IsAsyncImplFunc()) {
                ComposeAsyncImplFuncReturnType(checker, scriptFunc);
            }

            for (auto &returnStatement : scriptFunc->ReturnStatements()) {
                returnStatement->SetReturnType(checker, scriptFunc->Signature()->ReturnType());
            }
        }

        checker->Context().SetContainingSignature(nullptr);
    }
}

void ComposeAsyncImplFuncReturnType(ETSChecker *checker, ir::ScriptFunction *scriptFunc)
{
    const auto &promiseGlobal = checker->GlobalBuiltinPromiseType()->AsETSObjectType();
    auto promiseType =
        promiseGlobal->Instantiate(checker->Allocator(), checker->Relation(), checker->GetGlobalTypesHolder())
            ->AsETSObjectType();
    promiseType->AddTypeFlag(checker::TypeFlag::GENERIC);
    promiseType->TypeArguments().clear();
    promiseType->TypeArguments().emplace_back(scriptFunc->Signature()->ReturnType());

    auto *objectId =
        checker->AllocNode<ir::Identifier>(compiler::Signatures::BUILTIN_OBJECT_CLASS, checker->Allocator());
    objectId->SetReference();
    checker->VarBinder()->AsETSBinder()->LookupTypeReference(objectId, false);
    auto *returnType = checker->AllocNode<ir::ETSTypeReference>(
        checker->AllocNode<ir::ETSTypeReferencePart>(objectId, nullptr, nullptr));
    objectId->SetParent(returnType->Part());
    returnType->Part()->SetParent(returnType);
    returnType->SetTsType(
        checker->Allocator()->New<ETSAsyncFuncReturnType>(checker->Allocator(), checker->Relation(), promiseType));
    returnType->Check(checker);
    scriptFunc->Signature()->SetReturnType(returnType->TsType());
}

void ComposeAsyncImplMethod(ETSChecker *checker, ir::MethodDefinition *node)
{
    auto *classDef = checker->FindAncestorGivenByType(node, ir::AstNodeType::CLASS_DEFINITION)->AsClassDefinition();
    auto *scriptFunc = node->Function();
    ir::MethodDefinition *implMethod = checker->CreateAsyncProxy(node, classDef);

    implMethod->Check(checker);
    node->SetAsyncPairMethod(implMethod);

    if (scriptFunc->Signature()->HasSignatureFlag(SignatureFlags::NEED_RETURN_TYPE)) {
        node->Function()->Signature()->SetReturnType(
            implMethod->Function()->Signature()->ReturnType()->AsETSAsyncFuncReturnType()->PromiseType());
        scriptFunc->Signature()->RemoveSignatureFlag(SignatureFlags::NEED_RETURN_TYPE);
    }

    if (node->Function()->IsOverload()) {
        auto *baseOverloadImplMethod = node->BaseOverloadMethod()->AsyncPairMethod();
        implMethod->Function()->Id()->SetVariable(baseOverloadImplMethod->Function()->Id()->Variable());
        baseOverloadImplMethod->AddOverload(implMethod);
    } else {
        classDef->Body().push_back(implMethod);
    }
}

void CheckPredefinedMethodReturnType(ETSChecker *checker, ir::ScriptFunction *scriptFunc)
{
    auto const &position = scriptFunc->Start();

    if (scriptFunc->IsSetter() && (scriptFunc->Signature()->ReturnType() != checker->GlobalVoidType())) {
        checker->ThrowTypeError("Setter must have void return type", position);
    }

    if (scriptFunc->IsGetter() && (scriptFunc->Signature()->ReturnType() == checker->GlobalVoidType())) {
        checker->ThrowTypeError("Getter must return a value", position);
    }

    auto const name = scriptFunc->Id()->Name();
    auto const methodName = std::string {ir::PREDEFINED_METHOD} + std::string {name.Utf8()};

    if (name.Is(compiler::Signatures::GET_INDEX_METHOD)) {
        if (scriptFunc->Signature()->ReturnType() == checker->GlobalVoidType()) {
            checker->ThrowTypeError(methodName + "' shouldn't have void return type.", position);
        }
    } else if (name.Is(compiler::Signatures::SET_INDEX_METHOD)) {
        if (scriptFunc->Signature()->ReturnType() != checker->GlobalVoidType()) {
            checker->ThrowTypeError(methodName + "' should have void return type.", position);
        }
    } else if (name.Is(compiler::Signatures::ITERATOR_METHOD)) {
        CheckIteratorMethodReturnType(checker, scriptFunc, position, methodName);
    }
}

static bool HasIteratorInterface(ETSObjectType const *const objectType)
{
    auto const hasIteratorInterfaceImpl = [](ETSObjectType const *const checkType,
                                             auto &&iteratorInterfaceImpl) -> bool {
        if (checkType->Name().Is(ir::ITERATOR_INTERFACE_NAME)) {
            return true;
        }
        for (const auto *const interface : checkType->Interfaces()) {
            if (iteratorInterfaceImpl(interface, iteratorInterfaceImpl)) {
                return true;
            }
        }
        return false;
    };

    return hasIteratorInterfaceImpl(objectType, hasIteratorInterfaceImpl);
}

void CheckIteratorMethodReturnType(ETSChecker *checker, ir::ScriptFunction *scriptFunc,
                                   const lexer::SourcePosition &position, const std::string &methodName)
{
    const auto *returnType = scriptFunc->Signature()->ReturnType();

    if (returnType == nullptr) {
        checker->ThrowTypeError(methodName + "' doesn't have return type.", position);
    }

    if (returnType->IsETSTypeParameter()) {
        returnType = checker->GetApparentType(returnType->AsETSTypeParameter()->GetConstraintType());
    }

    if (returnType->IsETSObjectType() && HasIteratorInterface(returnType->AsETSObjectType())) {
        return;
    }

    while (returnType->IsETSObjectType() && returnType->AsETSObjectType()->SuperType() != nullptr) {
        returnType = returnType->AsETSObjectType()->SuperType();
        if (returnType->IsETSObjectType() && HasIteratorInterface(returnType->AsETSObjectType())) {
            return;
        }
    }

    checker->ThrowTypeError(
        {"The return type of '", scriptFunc->Id()->Name(), "' must be a type that implements Iterator interface."},
        position);
}

checker::Type *InitAnonymousLambdaCallee(checker::ETSChecker *checker, ir::Expression *callee,
                                         checker::Type *calleeType)
{
    auto *const arrowFunc = callee->AsArrowFunctionExpression()->Function();

    ArenaVector<ir::Expression *> params {checker->Allocator()->Adapter()};
    checker->CopyParams(arrowFunc->Params(), params);
    checker::Type *funcReturnType = nullptr;

    auto *typeAnnotation = arrowFunc->ReturnTypeAnnotation();
    if (typeAnnotation != nullptr) {
        typeAnnotation = typeAnnotation->Clone(checker->Allocator(), nullptr);
        typeAnnotation->SetTsType(arrowFunc->ReturnTypeAnnotation()->TsType());
    } else if (arrowFunc->Signature()->ReturnType() != nullptr) {
        auto newTypeAnnotation = callee->AsArrowFunctionExpression()->CreateTypeAnnotation(checker);
        typeAnnotation = arrowFunc->ReturnTypeAnnotation();
        funcReturnType = newTypeAnnotation->GetType(checker);
    }

    auto signature = ir::FunctionSignature(nullptr, std::move(params), typeAnnotation);
    auto *funcType = checker->AllocNode<ir::ETSFunctionType>(std::move(signature), ir::ScriptFunctionFlags::NONE);

    funcType->SetScope(arrowFunc->Scope()->AsFunctionScope()->ParamScope());
    auto *const funcIface = typeAnnotation != nullptr ? funcType->Check(checker) : funcReturnType;
    checker->Relation()->SetNode(callee);
    checker->Relation()->IsAssignableTo(calleeType, funcIface);
    return funcIface;
}

checker::Signature *ResolveCallExtensionFunction(checker::ETSFunctionType *functionType, checker::ETSChecker *checker,
                                                 ir::CallExpression *expr)
{
    auto *memberExpr = expr->Callee()->AsMemberExpression();
    expr->Arguments().insert(expr->Arguments().begin(), memberExpr->Object());
    auto *signature =
        checker->ResolveCallExpressionAndTrailingLambda(functionType->CallSignatures(), expr, expr->Start());
    if (!signature->Function()->IsExtensionMethod()) {
        checker->ThrowTypeError({"Property '", memberExpr->Property()->AsIdentifier()->Name(),
                                 "' does not exist on type '", memberExpr->ObjType()->Name(), "'"},
                                memberExpr->Property()->Start());
    }
    expr->SetSignature(signature);
    expr->SetCallee(memberExpr->Property());
    memberExpr->Property()->AsIdentifier()->SetParent(expr);
    expr->Arguments()[0]->SetParent(expr);
    checker->HandleUpdatedCallExpressionNode(expr);
    // Set TsType for new Callee(original member expression's Object)
    expr->Callee()->Check(checker);
    return signature;
}

checker::Signature *ResolveCallForETSExtensionFuncHelperType(checker::ETSExtensionFuncHelperType *type,
                                                             checker::ETSChecker *checker, ir::CallExpression *expr)
{
    checker::Signature *signature = checker->ResolveCallExpressionAndTrailingLambda(
        type->ClassMethodType()->CallSignatures(), expr, expr->Start(), checker::TypeRelationFlag::NO_THROW);

    if (signature != nullptr) {
        if (expr->Callee()->IsMemberExpression()) {
            auto memberExpr = expr->Callee()->AsMemberExpression();
            auto var = type->ClassMethodType()->Variable();
            memberExpr->Property()->AsIdentifier()->SetVariable(var);
        }

        return signature;
    }

    return ResolveCallExtensionFunction(type->ExtensionMethodType(), checker, expr);
}

ArenaVector<checker::Signature *> GetUnionTypeSignatures(ETSChecker *checker, checker::ETSUnionType *etsUnionType)
{
    ArenaVector<checker::Signature *> callSignatures(checker->Allocator()->Adapter());

    for (auto *constituentType : etsUnionType->ConstituentTypes()) {
        if (constituentType->IsETSObjectType()) {
            ArenaVector<checker::Signature *> tmpCallSignatures(checker->Allocator()->Adapter());
            tmpCallSignatures = constituentType->AsETSObjectType()
                                    ->GetOwnProperty<checker::PropertyType::INSTANCE_METHOD>("invoke0")
                                    ->TsType()
                                    ->AsETSFunctionType()
                                    ->CallSignatures();
            callSignatures.insert(callSignatures.end(), tmpCallSignatures.begin(), tmpCallSignatures.end());
        }
        if (constituentType->IsETSFunctionType()) {
            ArenaVector<checker::Signature *> tmpCallSignatures(checker->Allocator()->Adapter());
            tmpCallSignatures = constituentType->AsETSFunctionType()->CallSignatures();
            callSignatures.insert(callSignatures.end(), tmpCallSignatures.begin(), tmpCallSignatures.end());
        }
        if (constituentType->IsETSUnionType()) {
            ArenaVector<checker::Signature *> tmpCallSignatures(checker->Allocator()->Adapter());
            tmpCallSignatures = GetUnionTypeSignatures(checker, constituentType->AsETSUnionType());
            callSignatures.insert(callSignatures.end(), tmpCallSignatures.begin(), tmpCallSignatures.end());
        }
    }

    return callSignatures;
}

ArenaVector<checker::Signature *> &ChooseSignatures(ETSChecker *checker, checker::Type *calleeType,
                                                    bool isConstructorCall, bool isFunctionalInterface,
                                                    bool isUnionTypeWithFunctionalInterface)
{
    static ArenaVector<checker::Signature *> unionSignatures(checker->Allocator()->Adapter());
    unionSignatures.clear();
    if (isConstructorCall) {
        return calleeType->AsETSObjectType()->ConstructSignatures();
    }
    if (isFunctionalInterface) {
        return calleeType->AsETSObjectType()
            ->GetOwnProperty<checker::PropertyType::INSTANCE_METHOD>(FUNCTIONAL_INTERFACE_INVOKE_METHOD_NAME)
            ->TsType()
            ->AsETSFunctionType()
            ->CallSignatures();
    }
    if (isUnionTypeWithFunctionalInterface) {
        unionSignatures = GetUnionTypeSignatures(checker, calleeType->AsETSUnionType());
        return unionSignatures;
    }
    return calleeType->AsETSFunctionType()->CallSignatures();
}

checker::ETSObjectType *ChooseCalleeObj(ETSChecker *checker, ir::CallExpression *expr, checker::Type *calleeType,
                                        bool isConstructorCall)
{
    if (isConstructorCall) {
        return calleeType->AsETSObjectType();
    }
    if (expr->Callee()->IsIdentifier()) {
        return checker->Context().ContainingClass();
    }
    ASSERT(expr->Callee()->IsMemberExpression());
    return expr->Callee()->AsMemberExpression()->ObjType();
}

void ProcessExclamationMark(ETSChecker *checker, ir::UnaryExpression *expr, checker::Type *operandType)
{
    if (checker->IsNullLikeOrVoidExpression(expr->Argument())) {
        auto tsType = checker->CreateETSBooleanType(true);
        tsType->AddTypeFlag(checker::TypeFlag::CONSTANT);
        expr->SetTsType(tsType);
        return;
    }

    if (operandType == nullptr || !operandType->IsConditionalExprType()) {
        checker->ThrowTypeError("Bad operand type, the type of the operand must be boolean type.",
                                expr->Argument()->Start());
    }

    auto exprRes = operandType->ResolveConditionExpr();
    if (std::get<0>(exprRes)) {
        auto tsType = checker->CreateETSBooleanType(!std::get<1>(exprRes));
        tsType->AddTypeFlag(checker::TypeFlag::CONSTANT);
        expr->SetTsType(tsType);
        return;
    }

    expr->SetTsType(checker->GlobalETSBooleanType());
}

void SetTsTypeForUnaryExpression(ETSChecker *checker, ir::UnaryExpression *expr, checker::Type *operandType)
{
    switch (expr->OperatorType()) {
        case lexer::TokenType::PUNCTUATOR_MINUS:
        case lexer::TokenType::PUNCTUATOR_PLUS: {
            if (operandType == nullptr || !operandType->HasTypeFlag(checker::TypeFlag::ETS_CONVERTIBLE_TO_NUMERIC)) {
                checker->ThrowTypeError("Bad operand type, the type of the operand must be numeric type.",
                                        expr->Argument()->Start());
            }

            if (operandType->HasTypeFlag(checker::TypeFlag::CONSTANT) &&
                expr->OperatorType() == lexer::TokenType::PUNCTUATOR_MINUS) {
                expr->SetTsType(checker->NegateNumericType(operandType, expr));
                break;
            }

            expr->SetTsType(operandType);
            break;
        }
        case lexer::TokenType::PUNCTUATOR_TILDE: {
            if (operandType == nullptr || !operandType->HasTypeFlag(checker::TypeFlag::ETS_CONVERTIBLE_TO_NUMERIC)) {
                checker->ThrowTypeError("Bad operand type, the type of the operand must be numeric type.",
                                        expr->Argument()->Start());
            }

            if (operandType->HasTypeFlag(checker::TypeFlag::CONSTANT)) {
                expr->SetTsType(checker->BitwiseNegateNumericType(operandType, expr));
                break;
            }

            expr->SetTsType(checker->SelectGlobalIntegerTypeForNumeric(operandType));
            break;
        }
        case lexer::TokenType::PUNCTUATOR_EXCLAMATION_MARK: {
            ProcessExclamationMark(checker, expr, operandType);
            break;
        }
        case lexer::TokenType::PUNCTUATOR_DOLLAR_DOLLAR: {
            expr->SetTsType(expr->Argument()->TsType());
            break;
        }
        default: {
            UNREACHABLE();
            break;
        }
    }
}

checker::ETSObjectType *CreateSyntheticType(ETSChecker *checker, util::StringView const &syntheticName,
                                            checker::ETSObjectType *lastObjectType, ir::Identifier *id)
{
    auto *syntheticObjType = checker->Allocator()->New<checker::ETSObjectType>(
        checker->Allocator(), syntheticName, syntheticName,
        std::make_tuple(id, checker::ETSObjectFlags::NO_OPTS, checker->Relation()));

    auto *classDecl = checker->Allocator()->New<varbinder::ClassDecl>(syntheticName);
    varbinder::LocalVariable *var =
        checker->Allocator()->New<varbinder::LocalVariable>(classDecl, varbinder::VariableFlags::CLASS);
    var->SetTsType(syntheticObjType);
    lastObjectType->AddProperty<checker::PropertyType::STATIC_FIELD>(var);
    syntheticObjType->SetEnclosingType(lastObjectType);
    return syntheticObjType;
}

// NOLINTBEGIN(modernize-avoid-c-arrays)
static constexpr char const INVALID_CONST_ASSIGNMENT[] = "Cannot assign a value to a constant variable ";
static constexpr char const INVALID_READONLY_ASSIGNMENT[] = "Cannot assign a value to a readonly variable ";
static constexpr char const ITERATOR_TYPE_ABSENT[] = "Cannot obtain iterator type in 'for-of' statement.";
// NOLINTEND(modernize-avoid-c-arrays)

checker::Type *GetIteratorType(ETSChecker *checker, checker::Type *elemType, ir::AstNode *left)
{
    // Just to avoid extra nested level(s)
    auto const getIterType = [checker, elemType](ir::VariableDeclarator *const declarator) -> checker::Type * {
        if (declarator->TsType() == nullptr) {
            if (auto *resolved = checker->FindVariableInFunctionScope(declarator->Id()->AsIdentifier()->Name(),
                                                                      varbinder::ResolveBindingOptions::ALL_NON_TYPE);
                resolved != nullptr) {
                resolved->SetTsType(elemType);
                return elemType;
            }
        } else {
            return declarator->TsType();
        }
        return nullptr;
    };

    checker::Type *iterType = nullptr;
    if (left->IsIdentifier()) {
        if (auto *const variable = left->AsIdentifier()->Variable(); variable != nullptr) {
            auto *decl = variable->Declaration();
            if (decl->IsConstDecl() || decl->IsReadonlyDecl()) {
                std::string_view errorMsg =
                    decl->IsConstDecl() ? INVALID_CONST_ASSIGNMENT : INVALID_READONLY_ASSIGNMENT;
                checker->ThrowTypeError({errorMsg, variable->Name()}, decl->Node()->Start());
            }
        }
        iterType = left->AsIdentifier()->TsType();
    } else if (left->IsVariableDeclaration()) {
        if (auto const &declarators = left->AsVariableDeclaration()->Declarators(); !declarators.empty()) {
            iterType = getIterType(declarators.front());
        }
    }

    if (iterType == nullptr) {
        checker->ThrowTypeError(ITERATOR_TYPE_ABSENT, left->Start());
    }
    return iterType;
}

void CheckArgumentVoidType(checker::Type *&funcReturnType, ETSChecker *checker, const std::string &name,
                           ir::ReturnStatement *st)
{
    if (name.find(compiler::Signatures::ETS_MAIN_WITH_MANGLE_BEGIN) != std::string::npos) {
        if (!funcReturnType->IsETSVoidType() && !funcReturnType->IsIntType()) {
            checker->ThrowTypeError("Bad return type, main enable only void or int type.", st->Start());
        }
    }
}

void CheckReturnType(ETSChecker *checker, checker::Type *funcReturnType, checker::Type *argumentType,
                     ir::Expression *stArgument, bool isAsync)
{
    if (funcReturnType->IsETSVoidType() || funcReturnType == checker->GlobalVoidType()) {
        if (argumentType != checker->GlobalVoidType()) {
            checker->ThrowTypeError("Unexpected return value, enclosing method return type is void.",
                                    stArgument->Start());
        }
        checker::AssignmentContext(checker->Relation(), stArgument, argumentType, funcReturnType, stArgument->Start(),
                                   {"Return statement type is not compatible with the enclosing method's return type."},
                                   checker::TypeRelationFlag::DIRECT_RETURN);
        return;
    }

    if (isAsync && funcReturnType->IsETSObjectType() &&
        funcReturnType->AsETSObjectType()->GetOriginalBaseType() == checker->GlobalBuiltinPromiseType()) {
        auto promiseArg = funcReturnType->AsETSObjectType()->TypeArguments()[0];
        checker::AssignmentContext(checker->Relation(), stArgument, argumentType, promiseArg, stArgument->Start(), {},
                                   checker::TypeRelationFlag::DIRECT_RETURN | checker::TypeRelationFlag::NO_THROW);
        if (checker->Relation()->IsTrue()) {
            return;
        }
    }

    const Type *targetType = checker->TryGettingFunctionTypeFromInvokeFunction(funcReturnType);
    const Type *sourceType = checker->TryGettingFunctionTypeFromInvokeFunction(argumentType);
    checker::AssignmentContext(
        checker->Relation(), stArgument, argumentType, funcReturnType, stArgument->Start(),
        {"Type '", sourceType, "' is not compatible with the enclosing method's return type '", targetType, "'"},
        checker::TypeRelationFlag::DIRECT_RETURN);
}

void InferReturnType(ETSChecker *checker, ir::ScriptFunction *containingFunc, checker::Type *&funcReturnType,
                     ir::Expression *stArgument)
{
    //  First (or single) return statement in the function:
    funcReturnType = stArgument == nullptr ? checker->GlobalVoidType() : stArgument->Check(checker);
    if (funcReturnType->HasTypeFlag(checker::TypeFlag::CONSTANT)) {
        // remove CONSTANT type modifier if exists
        funcReturnType =
            funcReturnType->Instantiate(checker->Allocator(), checker->Relation(), checker->GetGlobalTypesHolder());
        funcReturnType->RemoveTypeFlag(checker::TypeFlag::CONSTANT);
    }
    /*
    when st_argment is ArrowFunctionExpression, need infer type for st_argment
    example code:
    ```
    return () => {}
    ```
    */
    if (stArgument != nullptr && stArgument->IsArrowFunctionExpression()) {
        auto arrowFunc = stArgument->AsArrowFunctionExpression();
        auto typeAnnotation = arrowFunc->CreateTypeAnnotation(checker);

        auto *argumentType = arrowFunc->TsType();
        funcReturnType = typeAnnotation->GetType(checker);

        const Type *sourceType = checker->TryGettingFunctionTypeFromInvokeFunction(argumentType);
        const Type *targetType = checker->TryGettingFunctionTypeFromInvokeFunction(funcReturnType);

        checker::AssignmentContext(
            checker->Relation(), arrowFunc, argumentType, funcReturnType, stArgument->Start(),
            {"Type '", sourceType, "' is not compatible with the enclosing method's return type '", targetType, "'"},
            checker::TypeRelationFlag::DIRECT_RETURN);
    }

    containingFunc->Signature()->SetReturnType(funcReturnType);
    containingFunc->Signature()->RemoveSignatureFlag(checker::SignatureFlags::NEED_RETURN_TYPE);
    containingFunc->Signature()->AddSignatureFlag(checker::SignatureFlags::INFERRED_RETURN_TYPE);
    checker->VarBinder()->AsETSBinder()->BuildFunctionName(containingFunc);

    if (stArgument != nullptr && stArgument->IsObjectExpression()) {
        stArgument->AsObjectExpression()->SetPreferredType(funcReturnType);
    }
}

void ProcessReturnStatements(ETSChecker *checker, ir::ScriptFunction *containingFunc, checker::Type *&funcReturnType,
                             ir::ReturnStatement *st, ir::Expression *stArgument)
{
    funcReturnType = containingFunc->Signature()->ReturnType();

    if (stArgument == nullptr) {
        // previous return statement(s) have value
        if (!funcReturnType->IsETSVoidType() && funcReturnType != checker->GlobalVoidType()) {
            checker->ThrowTypeError("All return statements in the function should be empty or have a value.",
                                    st->Start());
        }
    } else {
        if (stArgument->IsObjectExpression()) {
            stArgument->AsObjectExpression()->SetPreferredType(funcReturnType);
        }

        if (stArgument->IsMemberExpression()) {
            checker->SetArrayPreferredTypeForNestedMemberExpressions(stArgument->AsMemberExpression(), funcReturnType);
        }

        checker::Type *argumentType = stArgument->Check(checker);

        //  previous return statement(s) don't have any value
        if (funcReturnType->IsETSVoidType() && !argumentType->IsETSVoidType()) {
            checker->ThrowTypeError("All return statements in the function should be empty or have a value.",
                                    stArgument->Start());
        }

        const auto name = containingFunc->Scope()->InternalName().Mutf8();
        CheckArgumentVoidType(funcReturnType, checker, name, st);

        // remove CONSTANT type modifier if exists
        if (argumentType->HasTypeFlag(checker::TypeFlag::CONSTANT)) {
            argumentType =
                argumentType->Instantiate(checker->Allocator(), checker->Relation(), checker->GetGlobalTypesHolder());
            argumentType->RemoveTypeFlag(checker::TypeFlag::CONSTANT);
        }

        auto *const relation = checker->Relation();
        relation->SetNode(stArgument);

        if (!relation->IsIdenticalTo(funcReturnType, argumentType)) {
            checker->ResolveReturnStatement(funcReturnType, argumentType, containingFunc, st);
        }

        relation->SetNode(nullptr);
        relation->SetFlags(checker::TypeRelationFlag::NONE);
    }
}

ETSObjectType *CreateOptionalSignaturesForFunctionalType(ETSChecker *checker, ir::ETSFunctionType *node,
                                                         ETSObjectType *genericInterfaceType,
                                                         Substitution *substitution, size_t optionalParameterIndex)
{
    const auto &params = node->Params();
    auto returnType = node->ReturnType()->GetType(checker);

    for (size_t i = 0; i < optionalParameterIndex; i++) {
        checker::ETSChecker::EmplaceSubstituted(
            substitution, genericInterfaceType->TypeArguments()[i]->AsETSTypeParameter()->GetOriginal(),
            InstantiateBoxedPrimitiveType(checker, params[i],
                                          params[i]->AsETSParameterExpression()->TypeAnnotation()->GetType(checker)));
    }

    for (size_t i = optionalParameterIndex; i < params.size(); i++) {
        checker::ETSChecker::EmplaceSubstituted(
            substitution, genericInterfaceType->TypeArguments()[i]->AsETSTypeParameter()->GetOriginal(),
            CreateParamTypeWithDefaultParam(checker, params[i]));
    }

    checker::ETSChecker::EmplaceSubstituted(
        substitution,
        genericInterfaceType->TypeArguments()[genericInterfaceType->TypeArguments().size() - 1]
            ->AsETSTypeParameter()
            ->GetOriginal(),
        InstantiateBoxedPrimitiveType(checker, node->ReturnType(), returnType));

    return genericInterfaceType->Substitute(checker->Relation(), substitution)->AsETSObjectType();
}

ETSObjectType *CreateInterfaceTypeForETSFunctionType(ETSChecker *checker, ir::ETSFunctionType *node,
                                                     ETSObjectType *genericInterfaceType, Substitution *substitution)
{
    size_t i = 0;
    if (auto const &params = node->Params(); params.size() < checker->GlobalBuiltinFunctionTypeVariadicThreshold()) {
        for (; i < params.size(); i++) {
            checker::ETSChecker::EmplaceSubstituted(
                substitution, genericInterfaceType->TypeArguments()[i]->AsETSTypeParameter()->GetOriginal(),
                InstantiateBoxedPrimitiveType(
                    checker, params[i], params[i]->AsETSParameterExpression()->TypeAnnotation()->GetType(checker)));
        }
    }

    checker::ETSChecker::EmplaceSubstituted(
        substitution, genericInterfaceType->TypeArguments()[i]->AsETSTypeParameter()->GetOriginal(),
        InstantiateBoxedPrimitiveType(checker, node->ReturnType(), node->ReturnType()->GetType(checker)));
    return genericInterfaceType->Substitute(checker->Relation(), substitution)->AsETSObjectType();
}

Type *CreateParamTypeWithDefaultParam(ETSChecker *checker, ir::Expression *param)
{
    if (!param->AsETSParameterExpression()->IsDefault()) {
        checker->ThrowTypeError({"Expected initializer for ", param->AsETSParameterExpression()->Ident()->Name()},
                                param->Start());
    }

    ArenaVector<Type *> types(checker->Allocator()->Adapter());
    types.push_back(InstantiateBoxedPrimitiveType(
        checker, param, param->AsETSParameterExpression()->TypeAnnotation()->GetType(checker)));

    if (param->AsETSParameterExpression()->Initializer()->IsUndefinedLiteral()) {
        types.push_back(checker->GlobalETSUndefinedType());
    }

    return checker->CreateETSUnionType(Span<Type *const>(types));
}

Type *InstantiateBoxedPrimitiveType(ETSChecker *checker, ir::Expression *param, Type *paramType)
{
    if (paramType->HasTypeFlag(checker::TypeFlag::ETS_PRIMITIVE)) {
        auto node = checker->Relation()->GetNode();
        checker->Relation()->SetNode(param);
        auto *const boxedTypeArg = checker->PrimitiveTypeAsETSBuiltinType(paramType);
        ASSERT(boxedTypeArg);
        paramType =
            boxedTypeArg->Instantiate(checker->Allocator(), checker->Relation(), checker->GetGlobalTypesHolder());
        checker->Relation()->SetNode(node);
    }

    return paramType;
}
}  // namespace ark::es2panda::checker