Add ActiveModel::Error and NestedError

Add initialize_dup to deep dup.

Move proc eval and flexible message position out to Errors,
because proc eval is needed for Errors#added? and Errors#delete

activemodel/lib/active_model/error.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  # == Active \Model \Error
+  #
+  # Represents one single error
+  class Error
+    CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
+    MESSAGE_OPTIONS = [:message]
+
+    def initialize(base, attribute, type, **options)
+      @base = base
+      @attribute = attribute
+      @raw_type = type
+      @type = type || :invalid
+      @options = options
+    end
+
+    def initialize_dup(other)
+      @attribute = @attribute.dup
+      @raw_type = @raw_type.dup
+      @type = @type.dup
+      @options = @options.deep_dup
+    end
+
+    attr_reader :base, :attribute, :type, :raw_type, :options
+
+    def message
+      case raw_type
+      when Symbol
+        base.errors.generate_message(attribute, raw_type, options.except(*CALLBACKS_OPTIONS))
+      else
+        raw_type
+      end
+    end
+
+    def detail
+      { error: raw_type }.merge(options.except(*CALLBACKS_OPTIONS + MESSAGE_OPTIONS))
+    end
+
+    def full_message
+      base.errors.full_message(attribute, message)
+    end
+
+    # See if error matches provided +attribute+, +type+ and +options+.
+    def match?(attribute, type = nil, **options)
+      if @attribute != attribute || (type && @type != type)
+        return false
+      end
+
+      options.each do |key, value|
+        if @options[key] != value
+          return false
+        end
+      end
+
+      true
+    end
+  end
+end

activemodel/lib/active_model/errors.rb

@@ -59,9 +59,6 @@ module ActiveModel
   class Errors
     include Enumerable
 
-    CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
-    MESSAGE_OPTIONS = [:message]
-
     class << self
       attr_accessor :i18n_customize_full_message # :nodoc:
     end
@@ -532,19 +529,6 @@ module ActiveModel
     end
 
   private
-    def normalize_message(attribute, message, options)
-      case message
-      when Symbol
-        generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
-      else
-        message
-      end
-    end
-
-    def normalize_detail(message, options)
-      { error: message }.merge(options.except(*CALLBACKS_OPTIONS + MESSAGE_OPTIONS))
-    end
-
     def without_default_proc(hash)
       hash.dup.tap do |new_h|
         new_h.default_proc = nil

activemodel/lib/active_model/nested_error.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "active_model/error"
+require "forwardable"
+
+module ActiveModel
+  # Represents one single error
+  # @!attribute [r] base
+  #   @return [ActiveModel::Base] the object which the error belongs to
+  # @!attribute [r] attribute
+  #   @return [Symbol] attribute of the object which the error belongs to
+  # @!attribute [r] type
+  #   @return [Symbol] error's type
+  # @!attribute [r] options
+  #   @return [Hash] additional options
+  # @!attribute [r] inner_error
+  #   @return [Error] inner error
+  class NestedError < Error
+    def initialize(base, inner_error, override_options = {})
+      @base = base
+      @inner_error = inner_error
+      @attribute = override_options.fetch(:attribute) { inner_error.attribute }
+      @type = override_options.fetch(:type) { inner_error.type }
+      @raw_type = inner_error.raw_type
+      @options = inner_error.options
+    end
+
+    attr_reader :inner_error
+
+    extend Forwardable
+    def_delegators :@inner_error, :full_message, :message
+  end
+end

activemodel/test/cases/error_test.rb

@@ -0,0 +1,174 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "active_model/error"
+
+class ErrorTest < ActiveModel::TestCase
+  class Person
+    extend ActiveModel::Naming
+    def initialize
+      @errors = ActiveModel::Errors.new(self)
+    end
+
+    attr_accessor :name, :age
+    attr_reader   :errors
+
+    def read_attribute_for_validation(attr)
+      send(attr)
+    end
+
+    def self.human_attribute_name(attr, options = {})
+      attr
+    end
+
+    def self.lookup_ancestors
+      [self]
+    end
+  end
+
+  def test_initialize
+    base = Person.new
+    error = ActiveModel::Error.new(base, :name, :too_long, foo: :bar)
+    assert_equal base, error.base
+    assert_equal :name, error.attribute
+    assert_equal :too_long, error.type
+    assert_equal({ foo: :bar }, error.options)
+  end
+
+  test "initialize without type" do
+    error = ActiveModel::Error.new(Person.new, :name)
+    assert_equal :invalid, error.type
+    assert_equal({}, error.options)
+  end
+
+  test "initialize without type but with options" do
+    options = { message: "bar" }
+    error = ActiveModel::Error.new(Person.new, :name, options)
+    assert_equal :invalid, error.type
+    assert_equal(options, error.options)
+  end
+
+  # match?
+
+  test "match? handles mixed condition" do
+    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
+    assert_not subject.match?(:mineral, :too_coarse)
+    assert subject.match?(:mineral, :not_enough)
+    assert subject.match?(:mineral, :not_enough, count: 2)
+    assert_not subject.match?(:mineral, :not_enough, count: 1)
+  end
+
+  test "match? handles attribute match" do
+    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
+    assert_not subject.match?(:foo)
+    assert subject.match?(:mineral)
+  end
+
+  test "match? handles error type match" do
+    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
+    assert_not subject.match?(:mineral, :too_coarse)
+    assert subject.match?(:mineral, :not_enough)
+  end
+
+  test "match? handles extra options match" do
+    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
+    assert_not subject.match?(:mineral, :not_enough, count: 1)
+    assert subject.match?(:mineral, :not_enough, count: 2)
+  end
+
+  # message
+
+  test "message with type as a symbol" do
+    error = ActiveModel::Error.new(Person.new, :name, :blank)
+    assert_equal "can't be blank", error.message
+  end
+
+  test "message with custom interpolation" do
+    subject = ActiveModel::Error.new(Person.new, :name, :inclusion, message: "custom message %{value}", value: "name")
+    assert_equal "custom message name", subject.message
+  end
+
+  test "message returns plural interpolation" do
+    subject = ActiveModel::Error.new(Person.new, :name, :too_long, count: 10)
+    assert_equal "is too long (maximum is 10 characters)", subject.message
+  end
+
+  test "message returns singular interpolation" do
+    subject = ActiveModel::Error.new(Person.new, :name, :too_long, count: 1)
+    assert_equal "is too long (maximum is 1 character)", subject.message
+  end
+
+  test "message returns count interpolation" do
+    subject = ActiveModel::Error.new(Person.new, :name, :too_long, message: "custom message %{count}", count: 10)
+    assert_equal "custom message 10", subject.message
+  end
+
+  test "message handles lambda in messages and option values, and i18n interpolation" do
+    subject = ActiveModel::Error.new(Person.new, :name, :invalid,
+      foo: "foo",
+      bar: "bar",
+      baz: Proc.new { "baz" },
+      message: Proc.new { |model, options|
+        "%{attribute} %{foo} #{options[:bar]} %{baz}"
+      }
+    )
+    assert_equal "name foo bar baz", subject.message
+  end
+
+  test "generate_message works without i18n_scope" do
+    person = Person.new
+    error = ActiveModel::Error.new(person, :name, :blank)
+    assert_not_respond_to Person, :i18n_scope
+    assert_nothing_raised {
+      error.message
+    }
+  end
+
+  test "message with type as custom message" do
+    error = ActiveModel::Error.new(Person.new, :name, message: "cannot be blank")
+    assert_equal "cannot be blank", error.message
+  end
+
+  test "message with options[:message] as custom message" do
+    error = ActiveModel::Error.new(Person.new, :name, :blank, message: "cannot be blank")
+    assert_equal "cannot be blank", error.message
+  end
+
+  test "message renders lazily using current locale" do
+    error = nil
+
+    I18n.backend.store_translations(:pl, errors: { messages: { invalid: "jest nieprawidłowe" } })
+
+    I18n.with_locale(:en) { error = ActiveModel::Error.new(Person.new, :name, :invalid) }
+    I18n.with_locale(:pl) {
+      assert_equal "jest nieprawidłowe", error.message
+    }
+  end
+
+  test "message uses current locale" do
+    I18n.backend.store_translations(:en, errors: { messages: { inadequate: "Inadequate %{attribute} found!" } })
+    error = ActiveModel::Error.new(Person.new, :name, :inadequate)
+    assert_equal "Inadequate name found!", error.message
+  end
+
+  # full_message
+
+  test "full_message returns the given message when attribute is :base" do
+    error = ActiveModel::Error.new(Person.new, :base, message: "press the button")
+    assert_equal "press the button", error.full_message
+  end
+
+  test "full_message returns the given message with the attribute name included" do
+    error = ActiveModel::Error.new(Person.new, :name, :blank)
+    assert_equal "name can't be blank", error.full_message
+  end
+
+  test "full_message uses default format" do
+    error = ActiveModel::Error.new(Person.new, :name, message: "can't be blank")
+
+    # Use a locale without errors.format
+    I18n.with_locale(:unknown) {
+      assert_equal "name can't be blank", error.full_message
+    }
+  end
+end

activemodel/test/cases/nested_error_test.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "active_model/nested_error"
+require "models/topic"
+require "models/reply"
+
+class ErrorTest < ActiveModel::TestCase
+  def test_initialize
+    topic = Topic.new
+    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, count: 2)
+    reply = Reply.new
+    error = ActiveModel::NestedError.new(reply, inner_error)
+
+    assert_equal reply, error.base
+    assert_equal inner_error.attribute, error.attribute
+    assert_equal inner_error.type, error.type
+    assert_equal(inner_error.options, error.options)
+  end
+
+  test "initialize with overriding attribute and type" do
+    topic = Topic.new
+    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, count: 2)
+    reply = Reply.new
+    error = ActiveModel::NestedError.new(reply, inner_error, attribute: :parent, type: :foo)
+
+    assert_equal reply, error.base
+    assert_equal :parent, error.attribute
+    assert_equal :foo, error.type
+    assert_equal(inner_error.options, error.options)
+  end
+
+  def test_message
+    topic = Topic.new(author_name: "Bruce")
+    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, message: Proc.new { |model, options|
+      "not good enough for #{model.author_name}"
+    })
+    reply = Reply.new(author_name: "Mark")
+    error = ActiveModel::NestedError.new(reply, inner_error)
+
+    assert_equal "not good enough for Bruce", error.message
+  end
+
+  def test_full_message
+    topic = Topic.new(author_name: "Bruce")
+    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, message: Proc.new { |model, options|
+      "not good enough for #{model.author_name}"
+    })
+    reply = Reply.new(author_name: "Mark")
+    error = ActiveModel::NestedError.new(reply, inner_error)
+
+    assert_equal "Title not good enough for Bruce", error.full_message
+  end
+end