public async Task InvokeAsync()

in src/Microsoft.Azure.WebJobs.Host/Executors/FunctionExecutor.cs [1103:1168]
49 lines of code
7 McCabe index (conditional complexity)

            public async Task<object> InvokeAsync(object instance, object[] arguments)
            {
                // Invoke the filter pipeline.
                // Basic rules:
                // - Iff a Pre filter runs, then run the corresponding post. 
                // - if a pre-filter fails, short circuit the pipeline. Skip the remaining pre-filters and body.

                CancellationToken cancellationToken;
                int len = _filters.Count;
                int highestSuccessfulFilter = -1;

                Exception exception = null;
                var properties = _parameterHelper.FilterContextProperties;
                FunctionExecutingContext executingContext = new FunctionExecutingContext(_parameterHelper.GetParametersAsDictionary(), properties, _functionInstance.Id, _functionInstance.FunctionDescriptor.ShortName, _logger);
                try
                {
                    for (int i = 0; i < len; i++)
                    {
                        var filter = _filters[i];

                        await filter.OnExecutingAsync(executingContext, cancellationToken);

                        highestSuccessfulFilter = i;
                    }

                    var result = await _innerInvoker.InvokeAsync(instance, arguments);
                    return result;
                }
                catch (Exception ex)
                {
                    exception = ex;
                    throw;
                }
                finally
                {
                    var functionResult = exception != null ?
                        new FunctionResult(exception)
                        : new FunctionResult(true);
                    FunctionExecutedContext executedContext = new FunctionExecutedContext(_parameterHelper.GetParametersAsDictionary(), properties, _functionInstance.Id, _functionInstance.FunctionDescriptor.ShortName, _logger, functionResult);

                    // Run post filters in reverse order. 
                    // Only run the post if the corresponding pre executed successfully. 
                    for (int i = highestSuccessfulFilter; i >= 0; i--)
                    {
                        var filter = _filters[i];

                        try
                        {
                            await filter.OnExecutedAsync(executedContext, cancellationToken);
                        }
                        catch (Exception e)
                        {
                            exception = e;
                            executedContext.FunctionResult = new FunctionResult(exception);
                        }
                    }

                    // last exception wins. 
                    // If the body threw, then the finally will automatically rethrow that. 
                    // If a post-filter throws, capture that 
                    if (exception != null)
                    {
                        ExceptionDispatchInfo.Capture(exception).Throw();
                    }
                }
            }