feature: allow to override default values

anyway_config.gemspec

@@ -13,7 +13,6 @@ Gem::Specification.new do |s|
   s.summary     = "Configuration DSL for Ruby libraries and applications"
   s.description = %{
     Configuration DSL for Ruby libraries and applications.
-
     Allows you to easily follow the twelve-factor application principles (https://12factor.net/config).
   }
 
@@ -24,6 +23,6 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 2.2'
 
   s.add_development_dependency "rspec", "~> 3.5"
-  s.add_development_dependency "rubocop", "~> 0.49"
+  s.add_development_dependency "rubocop", "~> 0.52"
   s.add_development_dependency "simplecov", ">= 0.3.8"
 end

lib/anyway/config.rb

@@ -44,21 +44,35 @@ def config_name(val = nil)
       #   my_config = Anyway::Config.for(:my_app)
       #   # will load data from config/my_app.yml, secrets.my_app, ENV["MY_APP_*"]
       def for(name)
-        new(name, false).load_from_sources
+        new(name: name, load: false).load_from_sources
       end
     end
 
     attr_reader :config_name
 
-    def initialize(config_name = nil, do_load = true)
-      @config_name = config_name || self.class.config_name
+    # Instantiate config with specified name, loads the data and applies overrides
+    #
+    # Example:
+    #
+    #   my_config = Anyway::Config.new(:my_app, true, {overrides: {some: :value}})
+    #
+    # rubocop:disable Metrics/LineLength,Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
+    def initialize(config_name = nil, do_load = true, name: nil, load: true, overrides: {})
+      unless config_name.nil? && do_load.nil?
+        warn "[Deprecated] Positional arguments for Anyway::Config#initialize will be removed in 1.2.0. Use keyword arguments instead: initialize(name:, load:, overrides:)"
+      end
+      name = config_name unless config_name.nil?
+      load = do_load unless do_load.nil?
+
+      @config_name = name || self.class.config_name
       raise ArgumentError, "Config name is missing" unless @config_name
-      load if do_load
+      self.load(overrides) if load
     end
+    # rubocop:enable Metrics/LineLength,Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
 
-    def reload
+    def reload(overrides = {})
       clear
-      load
+      load(overrides)
       self
     end
 
@@ -69,8 +83,10 @@ def clear
       self
     end
 
-    def load
+    def load(overrides = {})
       config = load_from_sources((self.class.defaults || {}).deep_dup)
+
+      config.merge!(overrides) unless overrides.nil?
       config.each do |key, val|
         set_value(key, val)
       end
@@ -86,9 +102,7 @@ def load_from_sources(config = {})
     def load_from_file(config)
       config_path = Anyway.env.fetch(config_name).delete('conf') ||
                     "./config/#{config_name}.yml"
-      if config_path && File.file?(config_path)
-        config.deep_merge!(parse_yml(config_path) || {})
-      end
+      config.deep_merge!(parse_yml(config_path) || {}) if config_path && File.file?(config_path)
       config
     end
 

lib/anyway/rails/config.rb

@@ -18,9 +18,7 @@ def load_from_sources(config = {})
 
     def load_from_file(config)
       config_path = Rails.root.join("config", "#{@config_name}.yml")
-      if File.file? config_path
-        config.deep_merge!(parse_yml(config_path)[Rails.env] || {})
-      end
+      config.deep_merge!(parse_yml(config_path)[Rails.env] || {}) if File.file? config_path
       config
     end
 

spec/config_spec.rb

@@ -54,6 +54,11 @@
         expect(conf.host).to eq "test.host"
       end
 
+      it "sets overrides after loading YAML" do
+        config = CoolConfig.new(overrides: { host: 'overrided.host' })
+        expect(config.host).to eq "overrided.host"
+      end
+
       if Rails.application.respond_to?(:secrets)
         it "load config from secrets" do
           expect(conf.user[:name]).to eq "test"
@@ -79,6 +84,17 @@
         ENV['ANYWAY_SECRET_PASSWORD'] = 'my_pass'
         expect(conf.user[:password]).to eq 'my_pass'
       end
+
+      it "overrides loaded value by explicit" do
+        ENV['ANYWAY_SECRET_PASSWORD'] = 'my_pass'
+
+        config = CoolConfig.new(
+          overrides: {
+            user: { password: 'explicit_password' }
+          }
+        )
+        expect(config.user[:password]).to eq "explicit_password"
+      end
     end
 
     describe "clear" do
@@ -118,9 +134,7 @@
       data = Anyway::Config.for(:my_app)
       expect(data[:test]).to eq 1
       expect(data[:name]).to eq 'my_app'
-      if Rails.application.respond_to?(:secrets)
-        expect(data[:secret]).to eq 'my_secret'
-      end
+      expect(data[:secret]).to eq 'my_secret' if Rails.application.respond_to?(:secrets)
     end
   end
 
@@ -133,6 +147,14 @@
     end
   end
 
+  context "config with initial hash values" do
+    let(:conf) { SmallConfig.new(overrides: { 'meta': 'dummy' }) }
+
+    it "works" do
+      expect(conf.meta).to eq 'dummy'
+    end
+  end
+
   context "when name is missing" do
     let(:config) do
       Class.new(described_class)