SONARPY-4806 Preserve unknown decorators in serialized metadata

GitOrigin-RevId: f2c7fb1b5c2d0ee946ac9ae95f889b24e52e04cc

Author: guillaume-dequenne

python-frontend/src/main/java/org/sonar/python/semantic/FunctionSymbolImpl.java

@@ -104,7 +104,7 @@ public FunctionSymbolImpl(SymbolsProtos.FunctionSymbol functionSymbolProto, @Nul
     isInstanceMethod = containerClassFqn != null && !functionSymbolProto.getIsStatic() && !functionSymbolProto.getIsClassMethod();
     isAsynchronous = functionSymbolProto.getIsAsynchronous();
     hasDecorators = functionSymbolProto.getHasDecorators();
-    decorators = functionSymbolProto.getResolvedDecoratorNamesList();
+    decorators = resolvedDecoratorNames(functionSymbolProto.getResolvedDecoratorNamesList());
     SymbolsProtos.Type returnAnnotation = typeTable.resolve(
       functionSymbolProto.getReturnAnnotationId(), functionSymbolProto.hasReturnAnnotation(), functionSymbolProto.getReturnAnnotation());
     String returnTypeName = returnAnnotation == null ? "" : returnAnnotation.getFullyQualifiedName();
@@ -145,13 +145,18 @@ public FunctionSymbolImpl(FunctionDescriptor functionDescriptor, String symbolNa
     isInstanceMethod = functionDescriptor.isInstanceMethod();
     isAsynchronous = functionDescriptor.isAsynchronous();
     hasDecorators = functionDescriptor.hasDecorators();
-    decorators = functionDescriptor.decorators();
+    decorators = resolvedDecoratorNames(functionDescriptor.decorators());
     annotatedReturnTypeName = functionDescriptor.annotatedReturnTypeName();
     functionDefinitionLocation = functionDescriptor.definitionLocation();
     // TODO: Will no longer be true once SONARPY-647 is fixed
     isStub = false;
   }
 
+  private static List<String> resolvedDecoratorNames(List<String> names) {
+    // V1 exposes resolved names only. Keep unknown placeholders in descriptors for V2 consumers.
+    return names.stream().filter(name -> name != null && !name.isEmpty()).toList();
+  }
+
   public void setParametersWithType(ParameterList parametersList) {
     this.parameters.clear();
     createParameterNames(parametersList.all(), functionDefinitionLocation == null ? null : functionDefinitionLocation.fileId());

python-frontend/src/main/java/org/sonar/python/semantic/v2/converter/FunctionDescriptorToPythonTypeConverter.java

@@ -17,7 +17,6 @@
 package org.sonar.python.semantic.v2.converter;
 
 import java.util.List;
-import java.util.Objects;
 import java.util.Optional;
 import org.sonar.plugins.python.api.types.v2.ParameterV2;
 import org.sonar.plugins.python.api.types.v2.PythonType;
@@ -48,9 +47,9 @@ public PythonType convert(ConversionContext ctx, FunctionDescriptor from) {
 
     var decorators = from.decorators()
       .stream()
-      .filter(Objects::nonNull) // SONARPY-2813 needs to be done to fix the null decorators
-      .map(ctx.lazyTypesContext()::getOrCreateLazyType)
-      .map(TypeWrapper::of)
+      .map(decorator -> decorator == null || decorator.isEmpty()
+        ? TypeWrapper.UNKNOWN_TYPE_WRAPPER
+        : TypeWrapper.of(ctx.lazyTypesContext().getOrCreateLazyType(decorator)))
       .toList();
 
     var typeOrigin = ctx.typeOrigin();

python-frontend/src/main/java/org/sonar/python/semantic/v2/converter/PythonTypeToDescriptorConverter.java

@@ -134,8 +134,7 @@ private static Descriptor convert(FunctionType type) {
     var decorators = type.decorators()
       .stream()
       .map(TypeWrapper::type)
-      .map(decorator -> FullyQualifiedNameHelper.getFullyQualifiedName(decorator).orElse(null))
-      .filter(Objects::nonNull)
+      .map(decorator -> FullyQualifiedNameHelper.getFullyQualifiedName(decorator).orElse(""))
       .toList();
 
     var returnType = type.returnType();

python-frontend/src/main/java/org/sonar/python/semantic/v2/typeshed/FunctionSymbolToDescriptorConverter.java

@@ -62,7 +62,8 @@ public FunctionDescriptor convert(SymbolsProtos.FunctionSymbol functionSymbol, b
       .map(SymbolsProtos.FunctionSymbol::getResolvedDecoratorNamesList)
       .stream()
       .flatMap(Collection::stream)
-      .map(TypeShedUtils::normalizedFqn)
+      // Empty entries represent unknown decorators and must remain serializable in descriptor caches.
+      .map(name -> name.isEmpty() ? "" : TypeShedUtils.normalizedFqn(name))
       .toList();
     var parameters = functionSymbol.getParametersList().stream()
       .map(parameterConverter::convert)