1 files changed, 12 insertions, 3 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index 9f210c5f33..3f8b14bf67 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -123,13 +123,22 @@ module ActiveRecord
         def resolve(config)
           if config
             resolve_connection config
-          elsif defined?(Rails.env)
-            resolve_env_connection Rails.env.to_sym
+          elsif env = ActiveRecord::ConnectionHandling::RAILS_ENV.call
+            resolve_env_connection env.to_sym
           else
             raise AdapterNotSpecified
           end
         end
 
+        # Expands each key in @configurations hash into fully resolved hash
+        def resolve_all
+          config = configurations.dup
+          config.each do |key, value|
+            config[key] = resolve(value) if value
+          end
+          config
+        end
+
         # Returns an instance of ConnectionSpecification for a given adapter.
         # Accepts a hash one layer deep that contains all connection information.
         #
@@ -219,7 +228,7 @@ module ActiveRecord
           elsif spec.is_a?(String)
             resolve_string_connection(spec)
           else
-            raise(AdapterNotSpecified, "#{spec} database is not configured")
+            raise(AdapterNotSpecified, "'#{spec}' database is not configured. Available configuration: #{configurations.inspect}")
           end
         end