private BindingDataResolver GetResolver()

in src/Microsoft.Azure.WebJobs.Host/Bindings/AttributeCloner.cs [95:141]
32 lines of code
8 McCabe index (conditional complexity)

        private BindingDataResolver GetResolver(PropertyInfo propInfo, INameResolver nameResolver, BindingDataContract contract)
        {
            // Do the attribute lookups once upfront, and then cache them (via func closures) for subsequent runtime usage. 
            object originalValue = propInfo.GetValue(_source);
            ConnectionStringAttribute connStrAttr = propInfo.GetCustomAttribute<ConnectionStringAttribute>();
            AppSettingAttribute appSettingAttr = propInfo.GetCustomAttribute<AppSettingAttribute>();
            AutoResolveAttribute autoResolveAttr = propInfo.GetCustomAttribute<AutoResolveAttribute>();
            Validator validator = GetValidatorFunc(propInfo, appSettingAttr != null);

            if (appSettingAttr == null && autoResolveAttr == null && connStrAttr == null)
            {
                validator(originalValue);

                // No special attributes, treat as literal. 
                return (newAttr, bindingData) => originalValue;
            }

            int attrCount = new Attribute[] { connStrAttr, appSettingAttr, autoResolveAttr }.Count(a => a != null);
            if (attrCount > 1)
            {
                throw new InvalidOperationException($"Property '{propInfo.Name}' can only be annotated with one of the types {nameof(AppSettingAttribute)}, {nameof(AutoResolveAttribute)}, and {nameof(ConnectionStringAttribute)}.");
            }

            // attributes only work on string properties. 
            if (propInfo.PropertyType != typeof(string))
            {
                throw new InvalidOperationException($"{nameof(ConnectionStringAttribute)}, {nameof(AutoResolveAttribute)}, or {nameof(AppSettingAttribute)} property '{propInfo.Name}' must be of type string.");
            }

            var str = (string)originalValue;

            // first try to resolve with connection string
            if (connStrAttr != null)
            {
                return GetConfigurationResolver(str, connStrAttr.Default, propInfo, validator, s => _configuration.GetConnectionStringOrSetting(nameResolver.ResolveWholeString(s)));
            }

            // then app setting
            if (appSettingAttr != null)
            {
                return GetConfigurationResolver(str, appSettingAttr.Default, propInfo, validator, s => _configuration[s]);
            }

            // Must have an [AutoResolve]
            // try to resolve with auto resolve ({...}, %...%)
            return GetAutoResolveResolver(str, autoResolveAttr, nameResolver, propInfo, contract, validator);
        }