private static void ValidateApiGatewayEvents()

in Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Validation/LambdaFunctionValidator.cs [91:161]
59 lines of code
18 McCabe index (conditional complexity)

        private static void ValidateApiGatewayEvents(LambdaFunctionModel lambdaFunctionModel, Location methodLocation, List<Diagnostic> diagnostics)
        {
            // If the method does not contain any APIGatewayEvents, then it cannot return IHttpResults and can also not have parameters that are annotated with HTTP API attributes
            if (!lambdaFunctionModel.LambdaMethod.Events.Contains(EventType.API))
            {
                if (lambdaFunctionModel.LambdaMethod.ReturnsIHttpResults)
                {
                    diagnostics.Add(Diagnostic.Create(DiagnosticDescriptors.HttpResultsOnNonApiFunction, methodLocation));
                }

                foreach (var parameter in lambdaFunctionModel.LambdaMethod.Parameters)
                {
                    if (parameter.Attributes.Any(att =>
                        att.Type.FullName == TypeFullNames.FromBodyAttribute ||
                        att.Type.FullName == TypeFullNames.FromHeaderAttribute ||
                        att.Type.FullName == TypeFullNames.FromRouteAttribute ||
                        att.Type.FullName == TypeFullNames.FromQueryAttribute))
                    {
                        diagnostics.Add(Diagnostic.Create(DiagnosticDescriptors.ApiParametersOnNonApiFunction, methodLocation));
                    }
                }

                return;
            }

            // Validate FromRoute, FromQuery and FromHeader parameters
            foreach (var parameter in lambdaFunctionModel.LambdaMethod.Parameters)
            {
                if (parameter.Attributes.Any(att => att.Type.FullName == TypeFullNames.FromQueryAttribute))
                {
                    var fromQueryAttribute = parameter.Attributes.First(att => att.Type.FullName == TypeFullNames.FromQueryAttribute) as AttributeModel<APIGateway.FromQueryAttribute>;
                    // Use parameter name as key, if Name has not specified explicitly in the attribute definition.
                    var parameterKey = fromQueryAttribute?.Data?.Name ?? parameter.Name;

                    if (!parameter.Type.IsPrimitiveType() && !parameter.Type.IsPrimitiveEnumerableType())
                    {
                        diagnostics.Add(Diagnostic.Create(DiagnosticDescriptors.UnsupportedMethodParameterType, methodLocation, parameter.Name, parameter.Type.FullName));
                    }
                }

                foreach (var att in parameter.Attributes)
                {
                    var parameterAttributeName = string.Empty;
                    switch (att.Type.FullName)
                    {
                        case TypeFullNames.FromQueryAttribute:
                            var fromQueryAttribute = (AttributeModel<APIGateway.FromQueryAttribute>)att;
                            parameterAttributeName = fromQueryAttribute.Data.Name;
                            break;

                        case TypeFullNames.FromRouteAttribute:
                            var fromRouteAttribute = (AttributeModel<APIGateway.FromRouteAttribute>)att;
                            parameterAttributeName = fromRouteAttribute.Data.Name;
                            break;

                        case TypeFullNames.FromHeaderAttribute:
                            var fromHeaderAttribute = (AttributeModel<APIGateway.FromHeaderAttribute>)att;
                            parameterAttributeName = fromHeaderAttribute.Data.Name;
                            break;

                        default:
                            break;
                    }

                    if (!string.IsNullOrEmpty(parameterAttributeName) && !_parameterAttributeNameRegex.IsMatch(parameterAttributeName))
                    {
                        diagnostics.Add(Diagnostic.Create(DiagnosticDescriptors.InvalidParameterAttributeName, methodLocation, parameterAttributeName, parameter.Name));
                    }
                }
            }
        }