Enabled CollectionPropertiesShouldBeReadOnly rule and fixed related warnings.

Removed duplicated entries from editorconfig and cleaned it up.
Removed some redundant initializers from code.

.editorconfig

@@ -34,6 +34,7 @@ charset = utf-8-bom
 [*.{cs,vb}]
 # Organize usings
 dotnet_sort_system_directives_first = true
+dotnet_separate_import_directive_groups = false
 
 # this. preferences
 dotnet_style_qualification_for_field = false:suggestion
@@ -45,6 +46,11 @@ dotnet_style_qualification_for_event = false:suggestion
 dotnet_style_predefined_type_for_locals_parameters_members = true:suggestion
 dotnet_style_predefined_type_for_member_access = true:suggestion
 
+# Parentheses preferences
+dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_other_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_other_operators = never_if_unnecessary:silent
 # Modifier preferences
 dotnet_style_require_accessibility_modifiers = for_non_interface_members:suggestion
 dotnet_style_readonly_field = true:suggestion
@@ -52,8 +58,6 @@ dotnet_style_readonly_field = true:suggestion
 # Expression-level preferences
 dotnet_style_object_initializer = true:suggestion
 dotnet_style_collection_initializer = true:suggestion
-dotnet_style_coalesce_expression = true:suggestion
-dotnet_style_null_propagation = true:suggestion
 dotnet_style_explicit_tuple_names = true:suggestion
 dotnet_style_null_propagation = true:suggestion
 dotnet_style_coalesce_expression = true:suggestion
@@ -61,24 +65,26 @@ dotnet_style_prefer_is_null_check_over_reference_equality_method = true:none
 dotnet_prefer_inferred_tuple_names = true:suggestion
 dotnet_prefer_inferred_anonymous_type_member_names = true:suggestion
 dotnet_style_prefer_auto_properties = true:suggestion
+dotnet_style_prefer_conditional_expression_over_assignment = true:silent
+dotnet_style_prefer_conditional_expression_over_return = true:silent
 
 ###############################
 # Naming Conventions          #
 ###############################
 
 # Style Definitions
-dotnet_naming_style.pascal_case_style.capitalization             = pascal_case
+dotnet_naming_style.pascal_case_style.capitalization = pascal_case
 
 # Use PascalCase for constant fields  
 dotnet_naming_rule.constant_fields_should_be_pascal_case.severity = suggestion
-dotnet_naming_rule.constant_fields_should_be_pascal_case.symbols  = constant_fields
-dotnet_naming_rule.constant_fields_should_be_pascal_case.style    = pascal_case_style
-dotnet_naming_symbols.constant_fields.applicable_kinds            = field
-dotnet_naming_symbols.constant_fields.applicable_accessibilities  = *
-dotnet_naming_symbols.constant_fields.required_modifiers          = const
+dotnet_naming_rule.constant_fields_should_be_pascal_case.symbols = constant_fields
+dotnet_naming_rule.constant_fields_should_be_pascal_case.style = pascal_case_style
+dotnet_naming_symbols.constant_fields.applicable_kinds = field
+dotnet_naming_symbols.constant_fields.applicable_accessibilities = *
+dotnet_naming_symbols.constant_fields.required_modifiers = const
 
 ###############################
-# C# Coding Conventions       #
+# C# Code Style Rules         #
 ###############################
 [*.cs]
 # var preferences
@@ -87,14 +93,14 @@ csharp_style_var_when_type_is_apparent = true:suggestion
 csharp_style_var_elsewhere = true:suggestion
 
 # Expression-bodied members
-csharp_style_expression_bodied_methods = true:suggestion
+csharp_style_expression_bodied_methods = false:none
 csharp_style_expression_bodied_constructors = false:none
 csharp_style_expression_bodied_operators = true:suggestion
 csharp_style_expression_bodied_properties = true:suggestion
 csharp_style_expression_bodied_indexers = true:suggestion
 csharp_style_expression_bodied_accessors = true:suggestion
 
-# Pattern matching preferences
+# Pattern-matching preferences
 csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
 csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
 
@@ -125,132 +131,8 @@ csharp_new_line_before_members_in_anonymous_types = true
 csharp_new_line_between_query_expression_clauses = true
 
 # Indentation preferences
-csharp_indent_case_contents = true 
-csharp_indent_switch_labels = true 
-csharp_indent_labels = flush_left
-
-# Space preferences
-csharp_space_after_cast = false
-csharp_space_after_keywords_in_control_flow_statements = true
-csharp_space_between_method_call_parameter_list_parentheses = false 
-csharp_space_between_method_declaration_parameter_list_parentheses = false
-csharp_space_between_parentheses = false
-csharp_space_before_colon_in_inheritance_clause = true
-csharp_space_after_colon_in_inheritance_clause = true
-csharp_space_around_binary_operators = before_and_after
-csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
-csharp_space_between_method_call_name_and_opening_parenthesis = false
-csharp_space_between_method_call_empty_parameter_list_parentheses = false
-
-# Expression-level preferences
-csharp_prefer_braces = true:none
-csharp_style_deconstructed_variable_declaration = true:suggestion
-csharp_prefer_simple_default_expression = true:suggestion
-csharp_style_pattern_local_over_anonymous_function = true:suggestion
-csharp_style_inlined_variable_declaration = true:suggestion
-
-###############################
-# C# Formatting Rules         #
-###############################
-# New line preferences
-csharp_new_line_before_open_brace = all
-csharp_new_line_before_else = true
-csharp_new_line_before_catch = true
-csharp_new_line_before_finally = true
-csharp_new_line_before_members_in_object_initializers = true
-csharp_new_line_before_members_in_anonymous_types = true
-csharp_new_line_between_query_expression_clauses = true
-
-# Indentation preferences
-csharp_indent_case_contents = true 
-csharp_indent_switch_labels = true 
-csharp_indent_labels = flush_left
-
-# Space preferences
-csharp_space_after_cast = false
-csharp_space_after_keywords_in_control_flow_statements = true
-csharp_space_between_method_call_parameter_list_parentheses = false 
-csharp_space_between_method_declaration_parameter_list_parentheses = false
-csharp_space_between_parentheses = false
-csharp_space_before_colon_in_inheritance_clause = true
-csharp_space_after_colon_in_inheritance_clause = true
-csharp_space_around_binary_operators = before_and_after
-csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
-csharp_space_between_method_call_name_and_opening_parenthesis = false
-csharp_space_between_method_call_empty_parameter_list_parentheses = false
-csharp_style_expression_bodied_indexers = true:none
-csharp_style_expression_bodied_accessors = true:none
-
-# Pattern matching preferences
-csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
-csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
-
-# Null-checking preferences
-csharp_style_throw_expression = true:suggestion
-csharp_style_conditional_delegate_call = true:suggestion
-
-# Modifier preferences
-csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async:suggestion
-
-# Expression-level preferences
-csharp_prefer_braces = true:none
-csharp_style_deconstructed_variable_declaration = true:suggestion
-csharp_prefer_simple_default_expression = true:suggestion
-csharp_style_pattern_local_over_anonymous_function = true:suggestion
-csharp_style_inlined_variable_declaration = true:suggestion
-
-###############################
-# C# Formatting Rules         #
-###############################
-# New line preferences
-csharp_new_line_before_open_brace = all
-csharp_new_line_before_else = true
-csharp_new_line_before_catch = true
-csharp_new_line_before_finally = true
-csharp_new_line_before_members_in_object_initializers = true
-csharp_new_line_before_members_in_anonymous_types = true
-csharp_new_line_between_query_expression_clauses = true
-
-# Indentation preferences
-csharp_indent_case_contents = true 
-csharp_indent_switch_labels = true 
-csharp_indent_labels = flush_left
-
-# Space preferences
-csharp_space_after_cast = false
-csharp_space_after_keywords_in_control_flow_statements = true
-csharp_space_between_method_call_parameter_list_parentheses = false 
-csharp_space_between_method_declaration_parameter_list_parentheses = false
-csharp_space_between_parentheses = false
-csharp_space_before_colon_in_inheritance_clause = true
-csharp_space_after_colon_in_inheritance_clause = true
-csharp_space_around_binary_operators = before_and_after
-csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
-csharp_space_between_method_call_name_and_opening_parenthesis = false
-csharp_space_between_method_call_empty_parameter_list_parentheses = false
-
-# Expression-level preferences
-csharp_prefer_braces = true:none
-csharp_style_deconstructed_variable_declaration = true:suggestion
-csharp_prefer_simple_default_expression = true:suggestion
-csharp_style_pattern_local_over_anonymous_function = true:suggestion
-csharp_style_inlined_variable_declaration = true:suggestion
-
-###############################
-# C# Formatting Rules         #
-###############################
-# New line preferences
-csharp_new_line_before_open_brace = all
-csharp_new_line_before_else = true
-csharp_new_line_before_catch = true
-csharp_new_line_before_finally = true
-csharp_new_line_before_members_in_object_initializers = true
-csharp_new_line_before_members_in_anonymous_types = true
-csharp_new_line_between_query_expression_clauses = true
-
-# Indentation preferences
-csharp_indent_case_contents = true 
-csharp_indent_switch_labels = true 
+csharp_indent_case_contents = true
+csharp_indent_switch_labels = true
 csharp_indent_labels = flush_left
 
 # Space preferences
@@ -265,6 +147,8 @@ csharp_space_around_binary_operators = before_and_after
 csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
 csharp_space_between_method_call_name_and_opening_parenthesis = false
 csharp_space_between_method_call_empty_parameter_list_parentheses = false
+csharp_space_after_comma = true
+csharp_space_after_dot = false
 
 # Wrapping preferences
 csharp_preserve_single_line_statements = true

BotBuilder-DotNet.ruleset

@@ -189,8 +189,7 @@
   <Rules AnalyzerId="Microsoft.CodeQuality.Analyzers" RuleNamespace="Microsoft.CodeQuality.Analyzers">
 	<Rule Id="CA1054" Action="None" /> <!-- UriParametersShouldNotBeStrings -->
 	<Rule Id="CA1056" Action="None" /> <!-- UriPropertiesShouldNotBeStrings -->
-	<Rule Id="CA1062" Action="None" /> <!-- ValidateArgumentsOfPublicMethods -->
-	<Rule Id="CA2227" Action="None" /> <!-- CollectionPropertiesShouldBeReadOnly -->	
+	<Rule Id="CA1062" Action="None" /> <!-- ValidateArgumentsOfPublicMethods -->	
   </Rules>
   
   <Rules AnalyzerId="Microsoft.NetCore.Analyzers" RuleNamespace="Microsoft.NetCore.Analyzers">

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Twilio/TwilioMessage.cs

@@ -50,16 +50,16 @@ namespace Microsoft.Bot.Builder.Adapters.Twilio
         public string NumMedia { get; set; }
 
         /// <summary>
-        /// Gets or sets the URLs referencing the media content included with the message, if any.
+        /// Gets the URLs referencing the media content included with the message, if any.
         /// </summary>
         /// <value>URLs referencing the media content included with the message.</value>
-        public List<Uri> MediaUrls { get; set; }
+        public List<Uri> MediaUrls { get; } = new List<Uri>();
 
         /// <summary>
-        /// Gets or sets the content types for the media included with the message, if any.
+        /// Gets the content types for the media included with the message, if any.
         /// </summary>
         /// <value>The content types for the media included with the message.</value>
-        public List<string> MediaContentTypes { get; set; }
+        public List<string> MediaContentTypes { get; } = new List<string>();
 
         /// <summary>
         /// Gets or sets the receiver's city.

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Webex/AttachmentActionData.cs

@@ -48,11 +48,11 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         public string Created { get; set; }
 
         /// <summary>
-        /// Gets or sets the action's inputs.
+        /// Gets the action's inputs.
         /// </summary>
         /// <value>
         /// The action's inputs.
         /// </value>
-        public Dictionary<string, string> Inputs { get; set; }
+        public Dictionary<string, string> Inputs { get; } = new Dictionary<string, string>();
     }
 }

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Webex/WebexAdapter.cs

@@ -135,7 +135,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
             }
 
             var hookUrl = "https://" + _config.PublicAddress + webhookPath;
-            Webhook webhook = null;
+            Webhook webhook;
 
             if (hookId != null)
             {
@@ -167,7 +167,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
                 }
 
                 // transform activity into the webex message format
-                var personIdOrEmail = string.Empty;
+                string personIdOrEmail;
 
                 if (activity.GetChannelData<WebhookEventData>()?.MessageData.PersonEmail != null)
                 {
@@ -298,7 +298,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
             }
 
             WebhookEventData payload;
-            string json = null;
+            string json;
 
             using (var bodyStream = new StreamReader(request.Body))
             {

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Webex/WebexAdapterOptions.cs

@@ -17,10 +17,10 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         /// <param name="webhookName">A name for the webhook subscription.</param>
         public WebexAdapterOptions(string accessToken, string publicAddress, string secret, string webhookName = null)
         {
-            this.AccessToken = accessToken;
-            this.PublicAddress = publicAddress;
-            this.Secret = secret;
-            this.WebhookName = webhookName;
+            AccessToken = accessToken;
+            PublicAddress = publicAddress;
+            Secret = secret;
+            WebhookName = webhookName;
         }
 
         /// <summary>

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Webex/WebexClientWrapper.cs

@@ -120,7 +120,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         /// <returns>The attachment action details.</returns>
         public virtual async Task<Message> GetAttachmentActionAsync(string actionId, string token)
         {
-            Message result = null;
+            Message result;
 
             var url = $"{ActionsUrl}/{actionId}";
 
@@ -230,7 +230,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         /// <returns>The created <see cref="Webhook"/>.</returns>
         public virtual async Task<Webhook> CreateAdaptiveCardsWebhookAsync(string name, Uri targetUri, EventType type, string secret, string token)
         {
-            Webhook result = null;
+            Webhook result;
 
             var url = WebhookUrl;
             var data = new NameValueCollection
@@ -265,7 +265,7 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         /// <returns>The created <see cref="Webhook"/>.</returns>
         public virtual async Task<Webhook> UpdateAdaptiveCardsWebhookAsync(string webhookId, string name, Uri targetUri, string secret, string token)
         {
-            Webhook result = null;
+            Webhook result;
 
             var url = $"{WebhookUrl}/{webhookId}";
             var data = new NameValueCollection

libraries/Adapters/Microsoft.Bot.Builder.Adapters.Webex/WebexMessageRequest.cs

@@ -63,13 +63,13 @@ namespace Microsoft.Bot.Builder.Adapters.Webex
         public string Markdown { get; set; }
 
         /// <summary>
-        /// Gets or sets the URI to a binary file to be posted into the room. Only one file is allowed per message.
+        /// Gets the URI to a binary file to be posted into the room. Only one file is allowed per message.
         /// </summary>
         /// <value>
         /// The URI to a binary file to be posted into the room.
         /// </value>
         [JsonProperty(PropertyName = "files")]
-        public IList<Uri> Files { get; set; }
+        public IList<Uri> Files { get; } = new List<Uri>();
 
         /// <summary>
         /// Gets or sets the content attachments to attach to the message.