Don't parse expression on different line from return keyword

src/Binder/Binder.cpp

@@ -172,10 +172,13 @@ namespace Porygon::Binder {
         } else {
             currentReturnType = this->_currentFunction->GetReturnType();
         }
-        if (expression == nullptr && currentReturnType != nullptr) {
+        if (expression == nullptr && (currentReturnType != nullptr && currentReturnType -> GetClass() != TypeClass::Nil)) {
             this->_scriptData->Diagnostics->LogError(Diagnostics::DiagnosticCode::InvalidReturnType, statement->GetStartPosition(),
                                                      statement->GetLength());
             return new BoundBadStatement();
+        } else if (expression == nullptr){
+            currentReturnType = make_shared<ScriptType>(TypeClass::Nil);
+            return new BoundReturnStatement(nullptr);
         }
         auto boundExpression = this->BindExpression(expression);
         auto expresionType = boundExpression->GetType();

src/Evaluator/Evaluator.cpp

@@ -95,6 +95,7 @@ namespace Porygon::Evaluation {
         auto expression = statement->GetExpression();
         if (expression == nullptr) {
             this->_hasReturned = true;
+            this -> _returnValue = nullptr;
             return;
         }
         auto value = this->EvaluateExpression(expression);

src/Parser/Parser.cpp

@@ -192,8 +192,12 @@ namespace Porygon::Parser {
 
     ParsedStatement *Parser::ParseReturnStatement(const IToken *current) {
         //TODO: if next token is on a different line, don't parse it as return expression.
-        auto expression = this->ParseExpression(this->Next());
         auto start = current->GetStartPosition();
+        auto startLine = this -> ScriptData -> Diagnostics ->GetLineFromPosition(start);
+        if (startLine != this -> ScriptData -> Diagnostics -> GetLineFromPosition(this -> Peek() -> GetStartPosition())){
+            return new ParsedReturnStatement(nullptr, start, current->GetLength());
+        }
+        auto expression = this->ParseExpression(this->Next());
         return new ParsedReturnStatement(expression, start, expression->GetEndPosition() - start);
     }
 

tests/integration/Functions.cpp

@@ -136,5 +136,19 @@ test()
     delete script;
 }
 
+TEST_CASE( "Return doesn't parse next line expression", "[integration]" ) {
+    Script* script = Script::Create(
+            R"(
+return
+1 + 1
+)"
+    );
+    REQUIRE(!script->Diagnostics -> HasErrors());
+    auto result = script->Evaluate();
+    REQUIRE(result == nullptr);
+
+    delete script;
+}
+
 
 #endif