config.rb in anyway_config-2.0.0.rc1

- old
+ new

@@ -1,48 +1,121 @@
 # frozen_string_literal: true
 
 require "anyway/optparse_config"
 require "anyway/dynamic_config"
 
-require "anyway/ext/deep_dup"
-require "anyway/ext/deep_freeze"
-require "anyway/ext/hash"
-require "anyway/ext/string_serialize"
-
 module Anyway # :nodoc:
+  using RubyNext
   using Anyway::Ext::DeepDup
   using Anyway::Ext::DeepFreeze
   using Anyway::Ext::Hash
-  using Anyway::Ext::StringSerialize
 
+  using(Module.new do
+    refine Object do
+      def vm_object_id
+        (object_id << 1).to_s(16)
+      end
+    end
+  end)
+
   # Base config class
   # Provides `attr_config` method to describe
   # configuration parameters and set defaults
   class Config
+    PARAM_NAME = /^[a-z_]([\w]+)?$/
+
+    # List of names that couldn't be used as config names
+    # (the class instance methods we use)
+    RESERVED_NAMES = %i[
+      config_name
+      env_prefix
+      values
+      class
+      clear
+      deconstruct_keys
+      dig
+      initialize
+      load
+      load_from_sources
+      option_parser
+      pretty_print
+      raise_validation_error
+      reload
+      resolve_config_path
+      to_h
+      to_source_trace
+      write_config_attr
+    ].freeze
+
+    class Error < StandardError; end
+    class ValidationError < Error; end
+
     include OptparseConfig
     include DynamicConfig
 
+    class BlockCallback
+      attr_reader :block
+
+      def initialize(block)
+        @block = block
+      end
+
+      def apply_to(config)
+        config.instance_exec(&block)
+      end
+    end
+
+    class NamedCallback
+      attr_reader :name
+
+      def initialize(name)
+        @name = name
+      end
+
+      def apply_to(config)
+        config.send(name)
+      end
+    end
+
     class << self
       def attr_config(*args, **hargs)
         new_defaults = hargs.deep_dup
         new_defaults.stringify_keys!
 
         defaults.merge! new_defaults
 
-        new_keys = (args + new_defaults.keys) - config_attributes
+        new_keys = ((args + new_defaults.keys) - config_attributes)
+
+        validate_param_names! new_keys.map(&:to_s)
+
+        new_keys.map!(&:to_sym)
+
+        unless (reserved_names = (new_keys & RESERVED_NAMES)).empty?
+          raise ArgumentError, "Can not use the following reserved names as config attrubutes: " \
+            "#{reserved_names.sort.map(&:to_s).join(", ")}"
+        end
+
         config_attributes.push(*new_keys)
-        attr_accessor(*new_keys)
+
+        define_config_accessor(*new_keys)
+
+        # Define predicate methods ("param?") for attributes
+        # having `true` or `false` as default values
+        new_defaults.each do |key, val|
+          next unless val.is_a?(TrueClass) || val.is_a?(FalseClass)
+          alias_method :"#{key}?", :"#{key}"
+        end
       end
 
       def defaults
         return @defaults if instance_variable_defined?(:@defaults)
 
         @defaults =
           if superclass < Anyway::Config
             superclass.defaults.deep_dup
           else
-            {}
+            new_empty_config
           end
       end
 
       def config_attributes
         return @config_attributes if instance_variable_defined?(:@config_attributes)
@@ -53,10 +126,50 @@
           else
             []
           end
       end
 
+      def required(*names)
+        unless (unknown_names = (names - config_attributes)).empty?
+          raise ArgumentError, "Unknown config param: #{unknown_names.join(",")}"
+        end
+
+        required_attributes.push(*names)
+      end
+
+      def required_attributes
+        return @required_attributes if instance_variable_defined?(:@required_attributes)
+
+        @required_attributes =
+          if superclass < Anyway::Config
+            superclass.required_attributes.dup
+          else
+            []
+          end
+      end
+
+      def on_load(*names, &block)
+        raise ArgumentError, "Either methods or block should be specified, not both" if block_given? && !names.empty?
+
+        if block_given?
+          load_callbacks << BlockCallback.new(block)
+        else
+          load_callbacks.push(*names.map { NamedCallback.new(_1) })
+        end
+      end
+
+      def load_callbacks
+        return @load_callbacks if instance_variable_defined?(:@load_callbacks)
+
+        @load_callbacks =
+          if superclass <= Anyway::Config
+            superclass.load_callbacks.dup
+          else
+            []
+          end
+      end
+
       def config_name(val = nil)
         return (@explicit_config_name = val.to_s) unless val.nil?
 
         return @config_name if instance_variable_defined?(:@config_name)
 
@@ -87,12 +200,40 @@
           else
             config_name.upcase
           end
       end
 
+      def new_empty_config
+        {}
+      end
+
       private
 
+      def define_config_accessor(*names)
+        names.each do |name|
+          accessors_module.module_eval <<~RUBY, __FILE__, __LINE__ + 1
+            def #{name}=(val)
+              __trace__&.record_value(val, \"#{name}\", Tracing.current_trace_source)
+              # DEPRECATED: instance variable set will be removed in 2.1
+              @#{name} = values[:#{name}] = val
+            end
+
+            def #{name}
+              values[:#{name}]
+            end
+          RUBY
+        end
+      end
+
+      def accessors_module
+        return @accessors_module if instance_variable_defined?(:@accessors_module)
+
+        @accessors_module = Module.new.tap do |mod|
+          include mod
+        end
+      end
+
       def build_config_name
         unless name
           raise "Please, specify config name explicitly for anonymous class " \
             "via `config_name :my_config`"
         end
@@ -105,12 +246,22 @@
             "via `config_name :my_config`"
         end
 
         Regexp.last_match[1].tap(&:downcase!)
       end
+
+      def validate_param_names!(names)
+        invalid_names = names.reject { |name| name =~ PARAM_NAME }
+        return if invalid_names.empty?
+
+        raise ArgumentError, "Invalid attr_config name: #{invalid_names.join(", ")}.\n" \
+          "Valid names must satisfy /#{PARAM_NAME.source}/."
+      end
     end
 
+    on_load :validate_required_attributes!
+
     attr_reader :config_name, :env_prefix
 
     # Instantiate config instance.
     #
     # Example:
@@ -118,110 +269,136 @@
     #   my_config = Anyway::Config.new()
     #
     #   # provide some values explicitly
     #   my_config = Anyway::Config.new({some: :value})
     #
-    def initialize(overrides = {})
+    def initialize(overrides = nil)
       @config_name = self.class.config_name
 
       raise ArgumentError, "Config name is missing" unless @config_name
 
       @env_prefix = self.class.env_prefix
+      @values = {}
 
       load(overrides)
     end
 
-    def reload(overrides = {})
+    def reload(overrides = nil)
       clear
       load(overrides)
       self
     end
 
     def clear
-      self.class.config_attributes.each do |attr|
-        send("#{attr}=", nil)
-      end
+      values.clear
+      @__trace__ = nil
       self
     end
 
-    def load(overrides = {})
-      base_config = (self.class.defaults || {}).deep_dup
+    def load(overrides = nil)
+      base_config = self.class.defaults.deep_dup
 
-      base_config.deep_merge!(
+      trace = Tracing.capture do
+        Tracing.trace!(:defaults) { base_config }
+
         load_from_sources(
+          base_config,
           name: config_name,
           env_prefix: env_prefix,
           config_path: resolve_config_path(config_name, env_prefix)
         )
-      )
 
-      base_config.merge!(overrides) unless overrides.nil?
+        if overrides
+          Tracing.trace!(:load) { overrides }
 
+          base_config.deep_merge!(overrides)
+        end
+      end
+
       base_config.each do |key, val|
-        set_value(key, val)
+        write_config_attr(key.to_sym, val)
       end
+
+      # Trace may contain unknown attributes
+      trace&.keep_if { |key| self.class.config_attributes.include?(key.to_sym) }
+
+      # Run on_load callbacks
+      self.class.load_callbacks.each { _1.apply_to(self) }
+
+      # Set trace after we write all the values to
+      # avoid changing the source to accessor
+      @__trace__ = trace
+
+      self
     end
 
-    def load_from_sources(**options)
-      base_config = {}
-      each_source(options) do |config|
-        base_config.deep_merge!(config) if config
+    def load_from_sources(base_config, **options)
+      Anyway.loaders.each do |(_id, loader)|
+        base_config.deep_merge!(loader.call(**options))
       end
       base_config
     end
 
-    def each_source(options)
-      yield load_from_file(options)
-      yield load_from_env(options)
+    def dig(*keys)
+      values.dig(*keys)
     end
 
-    def load_from_file(name:, env_prefix:, config_path:, **_options)
-      file_config = load_from_yml(config_path)
+    def to_h
+      values.deep_dup.deep_freeze
+    end
 
-      if Anyway::Settings.use_local_files
-        local_config_path = config_path.sub(/\.yml/, ".local.yml")
-        file_config.deep_merge!(load_from_yml(local_config_path))
-      end
+    def resolve_config_path(name, env_prefix)
+      Anyway.env.fetch(env_prefix).delete("conf") || Settings.default_config_path.call(name)
+    end
 
-      file_config
+    def deconstruct_keys(keys)
+      values.deconstruct_keys(keys)
     end
 
-    def load_from_env(name:, env_prefix:, **_options)
-      Anyway.env.fetch(env_prefix)
+    def to_source_trace
+      __trace__&.to_h
     end
 
-    def to_h
-      self.class.config_attributes.each_with_object({}) do |key, obj|
-        obj[key.to_sym] = send(key)
-      end.deep_dup.deep_freeze
+    def inspect
+      "#<#{self.class}:0x#{vm_object_id.rjust(16, "0")} config_name=\"#{config_name}\" env_prefix=\"#{env_prefix}\" " \
+      "values=#{values.inspect}>"
     end
 
-    def resolve_config_path(name, env_prefix)
-      Anyway.env.fetch(env_prefix).delete("conf") || default_config_path(name)
+    def pretty_print(q)
+      q.object_group self do
+        q.nest(1) do
+          q.breakable
+          q.text "config_name=#{config_name.inspect}"
+          q.breakable
+          q.text "env_prefix=#{env_prefix.inspect}"
+          q.breakable
+          q.text "values:"
+          q.pp __trace__
+        end
+      end
     end
 
     private
 
-    def set_value(key, val)
-      send("#{key}=", val) if respond_to?(key)
+    attr_reader :values, :__trace__
+
+    def validate_required_attributes!
+      self.class.required_attributes.select do |name|
+        values[name].nil? || (values[name].is_a?(String) && values[name].empty?)
+      end.then do |missing|
+        next if missing.empty?
+        raise_validation_error "The following config parameters are missing or empty: #{missing.join(", ")}"
+      end
     end
 
-    def load_from_yml(path)
-      return {} unless File.file?(path)
+    def write_config_attr(key, val)
+      key = key.to_sym
+      return unless self.class.config_attributes.include?(key)
 
-      parse_yml(path)
+      public_send(:"#{key}=", val)
     end
 
-    def default_config_path(name)
-      "./config/#{name}.yml"
-    end
-
-    def parse_yml(path)
-      require "yaml"
-      if defined?(ERB)
-        YAML.safe_load(ERB.new(File.read(path)).result, [], [], true)
-      else
-        YAML.load_file(path)
-      end
+    def raise_validation_error(msg)
+      raise ValidationError, msg
     end
   end
 end