Initial AMo Lint implementation

activemodel/lib/active_model.rb

@@ -31,6 +31,7 @@ module ActiveModel
   autoload :DeprecatedErrorMethods, 'active_model/deprecated_error_methods'
   autoload :Dirty, 'active_model/dirty'
   autoload :Errors, 'active_model/errors'
+  autoload :Lint, 'active_model/lint'
   autoload :Name, 'active_model/naming'
   autoload :Naming, 'active_model/naming'
   autoload :Observer, 'active_model/observing'

activemodel/lib/active_model/lint.rb

@@ -0,0 +1,96 @@
+require "test/unit"
+require "test/unit/ui/console/testrunner"
+
+# You can test whether an object is compliant with the ActiveModel API by
+# calling ActiveModel::Compliance.test(object). It will emit a Test::Unit
+# output that tells you whether your object is fully compliant, or if not,
+# which aspects of the API are not implemented.
+#
+# These tests do not attempt to determine the semantic correctness of the
+# returned values. For instance, you could implement valid? to always
+# return true, and the tests would pass. It is up to you to ensure that
+# the values are semantically meaningful.
+#
+# Objects you pass in are expected to return a compliant object from a
+# call to to_model. It is perfectly fine for to_model to return self.
+
+module ActiveModel
+  module Lint
+    def self.test(object, verbosity = 2, output = STDOUT)
+      test_class = Class.new(::Test::Unit::TestCase) do
+        include Test
+
+        define_method(:setup) do
+          assert object.respond_to?(:to_model), "The object should respond_to :to_model"
+          @object = object.to_model
+          super
+        end
+      end
+
+      ::Test::Unit::UI::Console::TestRunner.new(test_class, verbosity, output).start
+    end
+
+    module Test
+      def assert_boolean(name, result)
+        assert result == true || result == false, "#{name} should be a boolean"
+      end
+
+      # valid?
+      # ------
+      #
+      # Returns a boolean that specifies whether the object is in a valid or invalid
+      # state.
+      def test_valid?
+        assert @object.respond_to?(:valid?), "The model should respond to valid?"
+        assert_boolean "valid?", @object.valid?
+      end
+
+      # new_record?
+      # -----------
+      #
+      # Returns a boolean that specifies whether the object has been persisted yet.
+      # This is used when calculating the URL for an object. If the object is
+      # not persisted, a form for that object, for instance, will be POSTed to the
+      # collection. If it is persisted, a form for the object will put PUTed to the
+      # URL for the object.
+      def test_new_record?
+        assert @object.respond_to?(:new_record?), "The model should respond to new_record?"
+        assert_boolean "new_record?", @object.new_record?
+      end
+
+      def test_destroyed?
+        assert @object.respond_to?(:new_record?), "The model should respond to destroyed?"
+        assert_boolean "destroyed?", @object.destroyed?
+      end
+
+      # errors
+      # ------
+      #
+      # Returns an object that has :[] and :full_messages defined on it. See below
+      # for more details.
+      def setup
+        assert @object.respond_to?(:errors), "The model should respond to errors"
+        @errors = @object.errors
+      end
+
+      # This module tests the #errors object
+      module Errors
+        # Returns an Array of Strings that are the errors for the attribute in
+        # question. If localization is used, the Strings should be localized
+        # for the current locale. If no error is present, this method should
+        # return an empty Array.
+        def test_errors_aref
+          assert @errors[:hello].is_a?(Array), "errors#[] should return an Array"
+        end
+
+        # Returns an Array of all error messages for the object. Each message
+        # should contain information about the field, if applicable.
+        def test_errors_full_messages
+          assert @errors.full_messages.is_a?(Array), "errors#full_messages should return an Array"
+        end
+      end
+
+      include Errors
+    end
+  end
+end

activemodel/test/cases/lint_test.rb

@@ -0,0 +1,50 @@
+require "cases/helper"
+
+class TestLint < Test::Unit::TestCase
+  class CompliantObject
+    def to_model
+      self
+    end
+
+    def valid?()      true end
+    def new_record?() true end
+    def destroyed?()  true end
+
+    def errors
+      obj = Object.new
+      def obj.[](key)         [] end
+      def obj.full_messages() [] end
+      obj
+    end
+  end
+
+  def assert_output(object, failures, errors, *test_names)
+    ActiveModel::Lint.test(object, 3, output = StringIO.new)
+    regex =  %r{#{failures} failures, #{errors} errors}
+    assert_match regex, output.string
+
+    test_names.each do |test_name|
+      assert_match test_name, output.string
+    end
+  end
+
+  def test_valid
+    assert_output(CompliantObject.new, 0, 0, /test_valid/)
+  end
+
+  def test_new_record
+    assert_output(CompliantObject.new, 0, 0, /test_new_record?/)
+  end
+
+  def test_destroyed
+    assert_output(CompliantObject.new, 0, 0, /test_destroyed/)
+  end
+
+  def test_errors_aref
+    assert_output(CompliantObject.new, 0, 0, /test_errors_aref/)
+  end
+
+  def test_errors_full_messages
+    assert_output(CompliantObject.new, 0, 0, /test_errors_aref/)
+  end
+end