1 files changed, 109 insertions, 0 deletions
diff --git a/railties/lib/rails/info.rb b/railties/lib/rails/info.rb
new file mode 100644
index 0000000000..c68405619d
--- /dev/null
+++ b/railties/lib/rails/info.rb
@@ -0,0 +1,109 @@
+# frozen_string_literal: true
+
+require "cgi"
+
+module Rails
+  # This module helps build the runtime properties that are displayed in
+  # Rails::InfoController responses. These include the active Rails version,
+  # Ruby version, Rack version, and so on.
+  module Info
+    mattr_accessor :properties, default: []
+
+    class << @@properties
+      def names
+        map(&:first)
+      end
+
+      def value_for(property_name)
+        if property = assoc(property_name)
+          property.last
+        end
+      end
+    end
+
+    class << self #:nodoc:
+      def property(name, value = nil)
+        value ||= yield
+        properties << [name, value] if value
+      rescue Exception
+      end
+
+      def to_s
+        column_width = properties.names.map(&:length).max
+        info = properties.map do |name, value|
+          value = value.join(", ") if value.is_a?(Array)
+          "%-#{column_width}s   %s" % [name, value]
+        end
+        info.unshift "About your application's environment"
+        info * "\n"
+      end
+
+      alias inspect to_s
+
+      def to_html
+        (+"<table>").tap do |table|
+          properties.each do |(name, value)|
+            table << %(<tr><td class="name">#{CGI.escapeHTML(name.to_s)}</td>)
+            formatted_value = if value.kind_of?(Array)
+              "<ul>" + value.map { |v| "<li>#{CGI.escapeHTML(v.to_s)}</li>" }.join + "</ul>"
+            else
+              CGI.escapeHTML(value.to_s)
+            end
+            table << %(<td class="value">#{formatted_value}</td></tr>)
+          end
+          table << "</table>"
+        end
+      end
+
+      def to_json
+        Hash[properties].to_json
+      end
+    end
+
+    # The Rails version.
+    property "Rails version" do
+      Rails.version.to_s
+    end
+
+    # The Ruby version and platform, e.g. "2.0.0-p247 (x86_64-darwin12.4.0)".
+    property "Ruby version" do
+      RUBY_DESCRIPTION
+    end
+
+    # The RubyGems version, if it's installed.
+    property "RubyGems version" do
+      Gem::RubyGemsVersion
+    end
+
+    property "Rack version" do
+      ::Rack.release
+    end
+
+    property "JavaScript Runtime" do
+      ExecJS.runtime.name
+    end
+
+    property "Middleware" do
+      Rails.configuration.middleware.map(&:inspect)
+    end
+
+    # The application's location on the filesystem.
+    property "Application root" do
+      File.expand_path(Rails.root)
+    end
+
+    # The current Rails environment (development, test, or production).
+    property "Environment" do
+      Rails.env
+    end
+
+    # The name of the database adapter for the current environment.
+    property "Database adapter" do
+      ActiveRecord::Base.configurations[Rails.env]["adapter"]
+    end
+
+    property "Database schema version" do
+      ActiveRecord::Base.connection.migration_context.current_version rescue nil
+    end
+  end
+end