Fix NoSuchElementException for listeners with inferred types

architecture-model-generator/modules/architecture-model-generator-core/src/main/java/io/ballerina/designmodelgenerator/core/CodeAnalyzer.java

@@ -347,25 +347,44 @@ public void visit(VariableDeclarationNode variableDeclarationNode) {
     @Override
     public void visit(ListenerDeclarationNode listenerDeclarationNode) {
         List<Listener.KeyValue> arguments = new ArrayList<>();
-        Optional<Symbol> symbol = semanticModel.symbol(listenerDeclarationNode.typeDescriptor().get());
+        Optional<TypeSymbol> typeSymbol;
+        String typeName;
         Node initializer = listenerDeclarationNode.initializer();
+
+        if (listenerDeclarationNode.typeDescriptor().isPresent()) {
+            // If explicit type descriptor is present, use it to get the type symbol and name
+            Optional<Symbol> symbol = semanticModel.symbol(listenerDeclarationNode.typeDescriptor().get());
+            typeSymbol = symbol.filter(s -> s instanceof TypeSymbol).map(s -> (TypeSymbol) s);
+            typeName = listenerDeclarationNode.typeDescriptor().get().toSourceCode().strip();
+        } else if (initializer instanceof ExplicitNewExpressionNode explicitNewExpressionNode) {
+            // If inferred type from explicit new expression
+            Optional<Symbol> symbol = semanticModel.symbol(explicitNewExpressionNode.typeDescriptor());
+            typeSymbol = symbol.filter(s -> s instanceof TypeSymbol).map(s -> (TypeSymbol) s);
+            typeName = explicitNewExpressionNode.typeDescriptor().toSourceCode().strip();
+        } else {
+            // Fallback to getting the type from the initializer expression
+            typeSymbol = semanticModel.typeOf(initializer);
+            typeName = typeSymbol.map(TypeSymbol::signature).orElse("");
+        }
+
         if (initializer instanceof NewExpressionNode newExpressionNode) {
-            if (symbol.isPresent() && symbol.get() instanceof TypeSymbol typeSymbol) {
-                TypeSymbol rawType = CommonUtils.getRawType(typeSymbol);
+            if (typeSymbol.isPresent()) {
+                TypeSymbol rawType = CommonUtils.getRawType(typeSymbol.get());
                 if (rawType instanceof ClassSymbol classSymbol) {
                     arguments = getInitMethodParamNames(classSymbol, connectionFinder.getArgList(newExpressionNode));
                 }
             }
         }
 
-        String icon = symbol.flatMap(Symbol::getModule)
+        String icon = typeSymbol.flatMap(Symbol::getModule)
                 .map(module -> CommonUtils.generateIcon(module.id())).orElse("");
         LineRange lineRange = listenerDeclarationNode.lineRange();
         String sortText = lineRange.fileName() + lineRange.startLine().line();
+
         this.intermediateModel.listeners.put(listenerDeclarationNode.variableName().text(),
                 new Listener(listenerDeclarationNode.variableName().text(), sortText,
                         getLocation(listenerDeclarationNode.lineRange()),
-                        listenerDeclarationNode.typeDescriptor().get().toSourceCode().strip(),
+                        typeName,
                         icon, Listener.Kind.NAMED, arguments, true));
     }
 

architecture-model-generator/modules/architecture-model-generator-ls-extension/src/test/resources/get_design_model/config/project_with_only_listener.json

@@ -0,0 +1,39 @@
+{
+  "description": "Project with only listener",
+  "projectPath": "project_8",
+  "output": {
+    "designModel": {
+      "connections": [],
+      "listeners": [
+        {
+          "symbol": "list",
+          "location": {
+            "filePath": "/Users/pasindufernando/Desktop/BI/Ballerina-Language-Server/ballerina-language-server/architecture-model-generator/modules/architecture-model-generator-ls-extension/src/test/resources/get_design_model/source/project_8/main.bal",
+            "startLine": {
+              "line": 2,
+              "offset": 0
+            },
+            "endLine": {
+              "line": 2,
+              "offset": 40
+            }
+          },
+          "attachedServices": [],
+          "kind": "NAMED",
+          "type": "http:Listener",
+          "args": [
+            {
+              "key": "port",
+              "value": "8080"
+            }
+          ],
+          "icon": "https://bcentral-packageicons.azureedge.net/images/ballerina_http_2.14.1.png",
+          "uuid": "PLACEHOLDER",
+          "enableFlowModel": true,
+          "sortText": "main.bal2"
+        }
+      ],
+      "services": []
+    }
+  }
+}

architecture-model-generator/modules/architecture-model-generator-ls-extension/src/test/resources/get_design_model/source/project_8/Ballerina.toml

@@ -0,0 +1,4 @@
+[package]
+org = "wso2"
+name = "service"
+version = "0.1.0"

architecture-model-generator/modules/architecture-model-generator-ls-extension/src/test/resources/get_design_model/source/project_8/main.bal

@@ -0,0 +1,3 @@
+import ballerina/http;
+
+listener list = new http:Listener(8080);