Ensure @export() is targeting top-level type statement

src/Bicep.Core.IntegrationTests/CompileTimeImportTests.cs

@@ -50,6 +50,22 @@ public void Importing_unexported_symbol_should_raise_diagnostic()
  });
  }
 
+ [TestMethod]
+ public void Exporting_type_property_should_raise_diagnostic()
+ {
+ var result = CompilationHelper.Compile(ServicesWithCompileTimeTypeImports, """
+ type foo = {
+ @export()
+ property: string
+ }
+ """);
+
+ result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[]
+ {
+ ("BCP358", DiagnosticLevel.Error, "The \"@export()\" decorator must target a top-level statement.")
+ });
+ }
+
  [TestMethod]
  public void Importing_non_template_should_raise_diagnostic()
  {

src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs

@@ -2005,6 +2005,11 @@ public ErrorDiagnostic RuntimeValueNotAllowedInFunctionDeclaration(string? acces
  TextSpan,
  "BCP357",
  $"The '{symbolName}' symbol was not found in (or was not exported by) the imported template.");
+
+ public ErrorDiagnostic ExportDecoratorMustTargetStatement() => new(
+ TextSpan,
+ "BCP358",
+ @"The ""@export()"" decorator must target a top-level statement.");
  }
 
  public static DiagnosticBuilderInternal ForPosition(TextSpan span)

src/Bicep.Core/Semantics/Namespaces/SystemNamespaceType.cs

@@ -14,6 +14,7 @@
 using Bicep.Core.FileSystem;
 using Bicep.Core.Intermediate;
 using Bicep.Core.Modules;
+using Bicep.Core.Navigation;
 using Bicep.Core.Parsing;
 using Bicep.Core.Syntax;
 using Bicep.Core.TypeSystem;
@@ -1441,11 +1442,20 @@ static void ValidateLength(string decoratorName, DecoratorSyntax decoratorSyntax
  yield return new DecoratorBuilder(LanguageConstants.ExportPropertyName)
  .WithDescription("Allows the type to be imported into other templates.")
  .WithFlags(FunctionFlags.TypeDecorator)
- .WithEvaluator((functionCall, decorated) => decorated switch
+ .WithEvaluator(static (functionCall, decorated) => decorated switch
  {
  DeclaredTypeExpression declaredType => declaredType with { Exported = functionCall },
  _ => decorated,
  })
+ .WithValidator(static (decoratorName, decoratorSyntax, _, _, binder, _, diagnosticWriter) =>
+ {
+ var decoratorTarget = binder.GetParent(decoratorSyntax);
+
+ if (decoratorTarget is not ITopLevelNamedDeclarationSyntax)
+ {
+ diagnosticWriter.Write(DiagnosticBuilder.ForPosition(decoratorSyntax).ExportDecoratorMustTargetStatement());
+ }
+ })
  .Build();
 
  yield return new DecoratorBuilder(LanguageConstants.ParameterAllowedPropertyName)