Add catch snippet

packages/http-client-csharp/generator/Microsoft.Generator.CSharp/src/Snippets/Snippet.DeclarationStatements.cs

@@ -59,5 +59,12 @@ public static MethodBodyStatement Declare<T>(string name, ScopedApi<T> value, ou
             variable = variableExpression.As<T>();
             return new DeclarationExpression(variableExpression).Assign(value).Terminate();
         }
+
+        public static DeclarationExpression Declare<T>(string name, out ScopedApi<T> variable)
+        {
+            var variableExpression = new VariableExpression(typeof(T), name);
+            variable = variableExpression.As<T>();
+            return new DeclarationExpression(variableExpression);
+        }
     }
 }

packages/http-client-csharp/generator/Microsoft.Generator.CSharp/src/Snippets/Snippet.cs

@@ -87,6 +87,8 @@ public static ValueExpression ArrayEmpty(CSharpType arrayItemType)
         public static AssignmentExpression Assign(this FieldProvider to, ValueExpression value, bool nullCoalesce = false) => new AssignmentExpression(to, value, nullCoalesce);
         public static AssignmentExpression Assign(this PropertyProvider to, ValueExpression value, bool nullCoalesce = false) => new AssignmentExpression(to, value, nullCoalesce);
 
+        public static CatchStatement Catch(DeclarationExpression declare, params MethodBodyStatement[] statements) => new CatchStatement(declare) { statements };
+
         public static MethodBodyStatement InvokeConsoleWriteLine(ValueExpression expression)
             => Static(typeof(Console)).Invoke(nameof(Console.WriteLine), expression).Terminate();
 

packages/http-client-csharp/generator/SamplePlugin/src/Providers/SamplePluginMethodProviderCollection.cs

@@ -9,6 +9,7 @@
 using Microsoft.Generator.CSharp.Input;
 using Microsoft.Generator.CSharp.Primitives;
 using Microsoft.Generator.CSharp.Providers;
+using Microsoft.Generator.CSharp.Snippets;
 using Microsoft.Generator.CSharp.Statements;
 using static Microsoft.Generator.CSharp.Snippets.Snippet;
 
@@ -36,19 +37,17 @@ protected override IReadOnlyList<MethodProvider> BuildMethods()
 
                 // Convert to a method with a body statement so we can add tracing.
                 ConvertToBodyStatementMethodProvider(method);
-                var ex = new VariableExpression(typeof(Exception), "ex");
-                var decl = new DeclarationExpression(ex);
                 var statements = new TryCatchFinallyStatement(
                     [
                         InvokeConsoleWriteLine(Literal($"Entering method {method.Signature.Name}.")),
                         method.BodyStatements!
                     ],
-                    new CatchStatement(decl)
-                        {
-                            InvokeConsoleWriteLine(new FormattableStringExpression(
-                                $"An exception was thrown in method {method.Signature.Name}: {{0}}", new[] { ex })),
-                            Throw()
-                        },
+                    Catch(Declare("ex", out ScopedApi<Exception> ex),
+                    [
+                        InvokeConsoleWriteLine(new FormattableStringExpression(
+                            $"An exception was thrown in method {method.Signature.Name}: {{0}}", new[] { ex })),
+                        Throw()
+                    ]),
                     [InvokeConsoleWriteLine(Literal($"Exiting method {method.Signature.Name}."))]);
 
                 method.Update(bodyStatements: statements);