🔧 Add client config (currently unused)

An (unused) client config object has been added to both Net::IMAP and to
ResponseParser.  Every client creates its own config object.  By
default, the client config inherits from the global config.

Unlike the client, which always creates a new Config object, the parser
simply shares the client's config.

Author: nevans

lib/net/imap.rb

@@ -769,6 +769,11 @@ class << self
     # Returns the initial greeting the server, an UntaggedResponse.
     attr_reader :greeting
 
+    # The client configuration.  See Net::IMAP::Config.
+    #
+    # By default, config inherits from the global Net::IMAP.config.
+    attr_reader :config
+
     # Seconds to wait until a connection is opened.
     # If the IMAP object cannot open a connection within this time,
     # it raises a Net::OpenTimeout exception. The default value is 30 seconds.
@@ -816,11 +821,20 @@ class << self
     #   the keys are names of attribute assignment methods on
     #   SSLContext[https://docs.ruby-lang.org/en/master/OpenSSL/SSL/SSLContext.html].
     #
+    # [config]
+    #   A Net::IMAP::Config object to base the client #config on.  By default
+    #   the global Net::IMAP.config is used.  Note that this sets the _parent_
+    #   config object for inheritance.  Every Net::IMAP client has its own
+    #   unique #config for overrides.
+    #
     # [open_timeout]
     #   Seconds to wait until a connection is opened
     # [idle_response_timeout]
     #   Seconds to wait until an IDLE response is received
     #
+    # Any other keyword arguments will be forwarded to Config.new, to create the
+    # client's #config.
+    #
     # See DeprecatedClientOptions.new for deprecated arguments.
     #
     # ==== Examples
@@ -877,10 +891,12 @@ class << self
     #   Connected to the host successfully, but it immediately said goodbye.
     #
     def initialize(host, port: nil, ssl:  nil,
-                   open_timeout: 30, idle_response_timeout: 5)
+                   open_timeout: 30, idle_response_timeout: 5,
+                   config: Config.global, **config_options)
       super()
       # Config options
       @host = host
+      @config = Config.new(config, **config_options)
       @port = port || (ssl ? SSL_PORT : PORT)
       @open_timeout = Integer(open_timeout)
       @idle_response_timeout = Integer(idle_response_timeout)
@@ -894,7 +910,7 @@ def initialize(host, port: nil, ssl:  nil,
       @capabilities = nil
 
       # Client Protocol Receiver
-      @parser = ResponseParser.new
+      @parser = ResponseParser.new(config: @config)
       @responses = Hash.new {|h, k| h[k] = [] }
       @response_handlers = []
       @receiver_thread = nil

lib/net/imap/config.rb

@@ -10,13 +10,17 @@ class IMAP
 
     # Net::IMAP::Config stores configuration options for Net::IMAP clients.
     # The global configuration can be seen at either Net::IMAP.config or
-    # Net::IMAP::Config.global.
+    # Net::IMAP::Config.global, and the client-specific configuration can be
+    # seen at Net::IMAP#config.  When creating a new client, all unhandled
+    # keyword arguments to Net::IMAP.new are delegated to Config.new.  Every
+    # client has its own config.
     #
     # ## Inheritance
     #
     # Configs have a parent[rdoc-ref:Config::AttrInheritance#parent] config, and
     # any attributes which have not been set locally will inherit the parent's
-    # value.  Config.global inherits from Config.default.
+    # value.  Every client creates its own specific config.  By default, client
+    # configs inherit from Config.global which inherits from Config.default.
     #
     # See the following methods, defined by Config::AttrInheritance:
     # - {#new}[rdoc-ref:Config::AttrInheritance#reset] -- create a new config

lib/net/imap/response_parser.rb

@@ -11,12 +11,15 @@ class ResponseParser
       include ParserUtils
       extend  ParserUtils::Generator
 
+      attr_reader :config
+
       # :call-seq: Net::IMAP::ResponseParser.new -> Net::IMAP::ResponseParser
-      def initialize
+      def initialize(config: Config.global)
         @str = nil
         @pos = nil
         @lex_state = nil
         @token = nil
+        @config = Config[config]
       end
 
       # :call-seq: