Add support for configuration via ENV

Author: skryukov

lib/inertia_rails/configuration.rb

@@ -29,8 +29,9 @@ class Configuration
 
     OPTION_NAMES = DEFAULTS.keys.freeze
 
-    protected attr_reader :controller
-    protected attr_reader :options
+    def self.default
+      new(**DEFAULTS).with_env_options
+    end
 
     def initialize(controller: nil, **attrs)
       @controller = controller
@@ -42,7 +43,7 @@ def initialize(controller: nil, **attrs)
     end
 
     def bind_controller(controller)
-      Configuration.new(**@options, controller: controller)
+      Configuration.new(**options, controller: controller)
     end
 
     def freeze
@@ -71,23 +72,40 @@ def component_path_resolver(path:, action:)
 
     OPTION_NAMES.each do |option|
       define_method(option) {
-        evaluate_option @options[option]
+        evaluate_option options[option]
       } unless method_defined?(option)
       define_method("#{option}=") { |value|
         @options[option] = value
       }
     end
 
-    def self.default
-      new(**DEFAULTS)
+    protected attr_reader :controller
+
+    def options
+      @with_env_options ? @options.merge(env_options) : @options
     end
+    protected :options
 
-  private
+    def with_env_options
+      @with_env_options = true
+      self
+    end
+
+    private
 
     def evaluate_option(value)
       return value unless value.respond_to?(:call)
       return value.call unless controller
       controller.instance_exec(&value)
     end
+
+    def env_options
+      @env_options ||= DEFAULTS.keys.each_with_object({}) do |key, hash|
+        value = ENV.fetch("INERTIA_#{key.to_s.upcase}", nil)
+        next if value.nil?
+
+        hash[key] = %w[true false].include?(value) ? value == 'true' : value
+      end
+    end
   end
 end

spec/inertia/configuration_spec.rb

@@ -16,21 +16,60 @@
         expect(merged_config.ssr_enabled).to eq false
       }.not_to raise_error
     end
+
+    context 'with environment variables' do
+      it 'always prioritizes environment variables' do
+        with_env(
+          'INERTIA_SSR_ENABLED' => 'true',
+          'INERTIA_SSR_URL' => 'http://env-ssr-url:1234',
+          'INERTIA_DEEP_MERGE_SHARED_DATA' => 'true'
+        ) do
+          config = InertiaRails::Configuration.default
+
+          config.ssr_enabled = false
+
+          expect(config.ssr_enabled).to eq true
+          expect(config.ssr_url).to eq 'http://env-ssr-url:1234'
+          expect(config.deep_merge_shared_data).to eq true
+        end
+      end
+
+      it 'respects environment variables when merging defaults' do
+        with_env(
+          'INERTIA_SSR_ENABLED' => 'true'
+        ) do
+          config = InertiaRails::Configuration.default
+          config.ssr_enabled = false
+          config.deep_merge_shared_data = true
+
+          controller_config = InertiaRails::Configuration.new(ssr_url: 'http://ssr-url:1234')
+          controller_config.with_defaults(config)
+
+          expect(controller_config.ssr_enabled).to eq true
+          expect(controller_config.ssr_url).to eq 'http://ssr-url:1234'
+          expect(controller_config.deep_merge_shared_data).to eq true
+        end
+      end
+    end
   end
 
   describe 'inertia_config' do
-    it 'overrides the global values' do
-      get configuration_path
-
-      expect(response.parsed_body.symbolize_keys).to include(
-        deep_merge_shared_data: true,
-        default_render: false,
-        layout: "test",
-        ssr_enabled: true,
-        ssr_url: "http://localhost:7777",
-        version: "2.0",
-        encrypt_history: false,
-      )
+    it 'overrides the global values and ENV' do
+      with_env(
+        'INERTIA_SSR_URL' => 'http://env-ssr-url:1234'
+      ) do
+        get configuration_path
+
+        expect(response.parsed_body.symbolize_keys).to include(
+          deep_merge_shared_data: true,
+          default_render: false,
+          layout: 'test',
+          ssr_enabled: true,
+          ssr_url: 'http://localhost:7777',
+          version: '2.0',
+          encrypt_history: false
+        )
+      end
     end
   end
 

spec/support/helper_module.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module HelperModule
   def with_forgery_protection
     orig = ActionController::Base.allow_forgery_protection
@@ -8,4 +10,14 @@ def with_forgery_protection
       ActionController::Base.allow_forgery_protection = orig
     end
   end
+
+  def with_env(**env)
+    orig = ENV.to_h
+    begin
+      ENV.replace(env)
+      yield if block_given?
+    ensure
+      ENV.replace(orig)
+    end
+  end
 end