Merge pull request #21511 from rwz/ar-exceptions-no-args

Removes mandatory arguments from AR exceptions

5 files changed, 178 insertions, 66 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 19ef37e228..65eb6fba27 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -5,65 +5,105 @@ require 'active_record/errors'
 
 module ActiveRecord
   class AssociationNotFoundError < ConfigurationError #:nodoc:
-    def initialize(record, association_name)
-      super("Association named '#{association_name}' was not found on #{record.class.name}; perhaps you misspelled it?")
+    def initialize(record = nil, association_name = nil)
+      if record && association_name
+        super("Association named '#{association_name}' was not found on #{record.class.name}; perhaps you misspelled it?")
+      else
+        super("Association was not found.")
+      end
     end
   end
 
   class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc:
-    def initialize(reflection, associated_class = nil)
-      super("Could not find the inverse association for #{reflection.name} (#{reflection.options[:inverse_of].inspect} in #{associated_class.nil? ? reflection.class_name : associated_class.name})")
+    def initialize(reflection = nil, associated_class = nil)
+      if reflection
+        super("Could not find the inverse association for #{reflection.name} (#{reflection.options[:inverse_of].inspect} in #{associated_class.nil? ? reflection.class_name : associated_class.name})")
+      else
+        super("Could not find the inverse association.")
+      end
     end
   end
 
   class HasManyThroughAssociationNotFoundError < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection)
-      super("Could not find the association #{reflection.options[:through].inspect} in model #{owner_class_name}")
+    def initialize(owner_class_name = nil, reflection = nil)
+      if owner_class_name && reflection
+        super("Could not find the association #{reflection.options[:through].inspect} in model #{owner_class_name}")
+      else
+        super("Could not find the association.")
+      end
     end
   end
 
   class HasManyThroughAssociationPolymorphicSourceError < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection, source_reflection)
-      super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' on the polymorphic object '#{source_reflection.class_name}##{source_reflection.name}' without 'source_type'. Try adding 'source_type: \"#{reflection.name.to_s.classify}\"' to 'has_many :through' definition.")
+    def initialize(owner_class_name = nil, reflection = nil, source_reflection = nil)
+      if owner_class_name && reflection && source_reflection
+        super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' on the polymorphic object '#{source_reflection.class_name}##{source_reflection.name}' without 'source_type'. Try adding 'source_type: \"#{reflection.name.to_s.classify}\"' to 'has_many :through' definition.")
+      else
+        super("Cannot have a has_many :through association.")
+      end
     end
   end
 
   class HasManyThroughAssociationPolymorphicThroughError < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection)
-      super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.")
+    def initialize(owner_class_name = nil, reflection = nil)
+      if owner_class_name && reflection
+        super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.")
+      else
+        super("Cannot have a has_many :through association.")
+      end
     end
   end
 
   class HasManyThroughAssociationPointlessSourceTypeError < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection, source_reflection)
-      super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' with a :source_type option if the '#{reflection.through_reflection.class_name}##{source_reflection.name}' is not polymorphic. Try removing :source_type on your association.")
+    def initialize(owner_class_name = nil, reflection = nil, source_reflection = nil)
+      if owner_class_name && reflection && source_reflection
+        super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' with a :source_type option if the '#{reflection.through_reflection.class_name}##{source_reflection.name}' is not polymorphic. Try removing :source_type on your association.")
+      else
+        super("Cannot have a has_many :through association.")
+      end
     end
   end
 
   class HasOneThroughCantAssociateThroughCollection < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection, through_reflection)
-      super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' where the :through association '#{owner_class_name}##{through_reflection.name}' is a collection. Specify a has_one or belongs_to association in the :through option instead.")
+    def initialize(owner_class_name = nil, reflection = nil, through_reflection = nil)
+      if owner_class_name && reflection && through_reflection
+        super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' where the :through association '#{owner_class_name}##{through_reflection.name}' is a collection. Specify a has_one or belongs_to association in the :through option instead.")
+      else
+        super("Cannot have a has_one :through association.")
+      end
     end
   end
 
   class HasOneAssociationPolymorphicThroughError < ActiveRecordError #:nodoc:
-    def initialize(owner_class_name, reflection)
-      super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.")
+    def initialize(owner_class_name = nil, reflection = nil)
+      if owner_class_name && reflection
+        super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.")
+      else
+        super("Cannot have a has_one :through association.")
+      end
     end
   end
 
   class HasManyThroughSourceAssociationNotFoundError < ActiveRecordError #:nodoc:
-    def initialize(reflection)
-      through_reflection      = reflection.through_reflection
-      source_reflection_names = reflection.source_reflection_names
-      source_associations     = reflection.through_reflection.klass._reflections.keys
-      super("Could not find the source association(s) #{source_reflection_names.collect(&:inspect).to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => <name>'. Is it one of #{source_associations.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)}?")
+    def initialize(reflection = nil)
+      if reflection
+        through_reflection      = reflection.through_reflection
+        source_reflection_names = reflection.source_reflection_names
+        source_associations     = reflection.through_reflection.klass._reflections.keys
+        super("Could not find the source association(s) #{source_reflection_names.collect(&:inspect).to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)} in model #{through_reflection.klass}. Try 'has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}, :source => <name>'. Is it one of #{source_associations.to_sentence(:two_words_connector => ' or ', :last_word_connector => ', or ', :locale => :en)}?")
+      else
+        super("Could not find the source association(s).")
+      end
     end
   end
 
   class ThroughCantAssociateThroughHasOneOrManyReflection < ActiveRecordError #:nodoc:
-    def initialize(owner, reflection)
-      super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.")
+    def initialize(owner = nil, reflection = nil)
+      if owner && reflection
+        super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.")
+      else
+        super("Cannot modify association.")
+      end
     end
   end
 
@@ -74,20 +114,32 @@ module ActiveRecord
   end
 
   class HasManyThroughCantAssociateNewRecords < ActiveRecordError #:nodoc:
-    def initialize(owner, reflection)
-      super("Cannot associate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to create the has_many :through record associating them.")
+    def initialize(owner = nil, reflection = nil)
+      if owner && reflection
+        super("Cannot associate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to create the has_many :through record associating them.")
+      else
+        super("Cannot associate new records.")
+      end
     end
   end
 
   class HasManyThroughCantDissociateNewRecords < ActiveRecordError #:nodoc:
-    def initialize(owner, reflection)
-      super("Cannot dissociate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to delete the has_many :through record associating them.")
+    def initialize(owner = nil, reflection = nil)
+      if owner && reflection
+        super("Cannot dissociate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to delete the has_many :through record associating them.")
+      else
+        super("Cannot dissociate new records.")
+      end
     end
   end
 
   class ThroughNestedAssociationsAreReadonly < ActiveRecordError #:nodoc:
-    def initialize(owner, reflection)
-      super("Cannot modify association '#{owner.class.name}##{reflection.name}' because it goes through more than one other association.")
+    def initialize(owner = nil, reflection = nil)
+      if owner && reflection
+        super("Cannot modify association '#{owner.class.name}##{reflection.name}' because it goes through more than one other association.")
+      else
+        super("Through nested associations are read-only.")
+      end
     end
   end
 
@@ -98,14 +150,22 @@ module ActiveRecord
   end
 
   class EagerLoadPolymorphicError < ActiveRecordError #:nodoc:
-    def initialize(reflection)
-      super("Cannot eagerly load the polymorphic association #{reflection.name.inspect}")
+    def initialize(reflection = nil)
+      if reflection
+        super("Cannot eagerly load the polymorphic association #{reflection.name.inspect}")
+      else
+        super("Eager load polymorphic error.")
+      end
     end
   end
 
   class ReadOnlyAssociation < ActiveRecordError #:nodoc:
-    def initialize(reflection)
-      super("Cannot add to a has_many :through association. Try adding to #{reflection.through_reflection.name.inspect}.")
+    def initialize(reflection = nil)
+      if reflection
+        super("Cannot add to a has_many :through association. Try adding to #{reflection.through_reflection.name.inspect}.")
+      else
+        super("Read-only reflection error.")
+      end
     end
   end
 
@@ -113,8 +173,12 @@ module ActiveRecord
   # (has_many, has_one) when there is at least 1 child associated instance.
   # ex: if @project.tasks.size > 0, DeleteRestrictionError will be raised when trying to destroy @project
   class DeleteRestrictionError < ActiveRecordError #:nodoc:
-    def initialize(name)
-      super("Cannot delete record because of dependent #{name}")
+    def initialize(name = nil)
+      if name
+        super("Cannot delete record because of dependent #{name}")
+      else
+        super("Delete restriction error.")
+      end
     end
   end
 
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 718f04871d..6721fe144f 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -63,7 +63,7 @@ module ActiveRecord
   class RecordNotSaved < ActiveRecordError
     attr_reader :record
 
-    def initialize(message, record = nil)
+    def initialize(message = nil, record = nil)
       @record = record
       super(message)
     end
@@ -80,7 +80,7 @@ module ActiveRecord
   class RecordNotDestroyed < ActiveRecordError
     attr_reader :record
 
-    def initialize(message, record = nil)
+    def initialize(message = nil, record = nil)
       @record = record
       super(message)
     end
@@ -92,9 +92,9 @@ module ActiveRecord
   class StatementInvalid < ActiveRecordError
     attr_reader :original_exception
 
-    def initialize(message, original_exception = nil)
-      super(message)
+    def initialize(message = nil, original_exception = nil)
       @original_exception = original_exception
+      super(message)
     end
   end
 
@@ -134,10 +134,14 @@ module ActiveRecord
   class StaleObjectError < ActiveRecordError
     attr_reader :record, :attempted_action
 
-    def initialize(record, attempted_action)
-      super("Attempted to #{attempted_action} a stale object: #{record.class.name}")
-      @record = record
-      @attempted_action = attempted_action
+    def initialize(record = nil, attempted_action = nil)
+      if record && attempted_action
+        @record = record
+        @attempted_action = attempted_action
+        super("Attempted to #{attempted_action} a stale object: #{record.class.name}.")
+      else
+        super("Stale object error.")
+      end
     end
 
   end
@@ -196,7 +200,7 @@ module ActiveRecord
   class AttributeAssignmentError < ActiveRecordError
     attr_reader :exception, :attribute
 
-    def initialize(message, exception, attribute)
+    def initialize(message = nil, exception = nil, attribute = nil)
       super(message)
       @exception = exception
       @attribute = attribute
@@ -209,7 +213,7 @@ module ActiveRecord
   class MultiparameterAssignmentErrors < ActiveRecordError
     attr_reader :errors
 
-    def initialize(errors)
+    def initialize(errors = nil)
       @errors = errors
     end
   end
@@ -218,11 +222,15 @@ module ActiveRecord
   class UnknownPrimaryKey < ActiveRecordError
     attr_reader :model
 
-    def initialize(model, description = nil)
-      message = "Unknown primary key for table #{model.table_name} in model #{model}."
-      message += "\n#{description}" if description
-      super(message)
-      @model = model
+    def initialize(model = nil, description = nil)
+      if model
+        message = "Unknown primary key for table #{model.table_name} in model #{model}."
+        message += "\n#{description}" if description
+        @model = model
+        super(message)
+      else
+        super("Unknown primary key.")
+      end
     end
   end
 
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index 112d52024f..3b90ab1e31 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -84,35 +84,53 @@ module ActiveRecord
   end
 
   class DuplicateMigrationVersionError < MigrationError#:nodoc:
-    def initialize(version)
-      super("Multiple migrations have the version number #{version}")
+    def initialize(version = nil)
+      if version
+        super("Multiple migrations have the version number #{version}.")
+      else
+        super("Duplicate migration version error.")
+      end
     end
   end
 
   class DuplicateMigrationNameError < MigrationError#:nodoc:
-    def initialize(name)
-      super("Multiple migrations have the name #{name}")
+    def initialize(name = nil)
+      if name
+        super("Multiple migrations have the name #{name}.")
+      else
+        super("Duplicate migration name.")
+      end
     end
   end
 
   class UnknownMigrationVersionError < MigrationError #:nodoc:
-    def initialize(version)
-      super("No migration with version number #{version}")
+    def initialize(version = nil)
+      if version
+        super("No migration with version number #{version}.")
+      else
+        super("Unknown migration version.")
+      end
     end
   end
 
   class IllegalMigrationNameError < MigrationError#:nodoc:
-    def initialize(name)
-      super("Illegal name for migration file: #{name}\n\t(only lower case letters, numbers, and '_' allowed)")
+    def initialize(name = nil)
+      if name
+        super("Illegal name for migration file: #{name}\n\t(only lower case letters, numbers, and '_' allowed).")
+      else
+        super("Illegal name for migration.")
+      end
     end
   end
 
   class PendingMigrationError < MigrationError#:nodoc:
-    def initialize
-      if defined?(Rails.env)
-        super("Migrations are pending. To resolve this issue, run:\n\n\tbin/rake db:migrate RAILS_ENV=#{::Rails.env}")
+    def initialize(message = nil)
+      if !message && defined?(Rails.env)
+        super("Migrations are pending. To resolve this issue, run:\n\n\tbin/rake db:migrate RAILS_ENV=#{::Rails.env}.")
+      elsif !message
+        super("Migrations are pending. To resolve this issue, run:\n\n\tbin/rake db:migrate.")
       else
-        super("Migrations are pending. To resolve this issue, run:\n\n\tbin/rake db:migrate")
+        super
       end
     end
   end
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 34d96b19fe..74daece4e8 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -12,10 +12,16 @@ module ActiveRecord
   class RecordInvalid < ActiveRecordError
     attr_reader :record
 
-    def initialize(record)
-      @record = record
-      errors = @record.errors.full_messages.join(", ")
-      super(I18n.t(:"#{@record.class.i18n_scope}.errors.messages.record_invalid", :errors => errors, :default => :"errors.messages.record_invalid"))
+    def initialize(record = nil)
+      if record
+        @record = record
+        errors = @record.errors.full_messages.join(", ")
+        message = I18n.t(:"#{@record.class.i18n_scope}.errors.messages.record_invalid", errors: errors, default: :"errors.messages.record_invalid")
+      else
+        message = "Record invalid"
+      end
+
+      super(message)
     end
   end
 
diff --git a/activerecord/test/cases/errors_test.rb b/activerecord/test/cases/errors_test.rb
new file mode 100644
index 0000000000..0711a372f2
--- /dev/null
+++ b/activerecord/test/cases/errors_test.rb
@@ -0,0 +1,16 @@
+require_relative "../cases/helper"
+
+class ErrorsTest < ActiveRecord::TestCase
+  def test_can_be_instantiated_with_no_args
+    base = ActiveRecord::ActiveRecordError
+    error_klasses = ObjectSpace.each_object(Class).select { |klass| klass < base }
+
+    error_klasses.each do |error_klass|
+      begin
+        error_klass.new.inspect
+      rescue ArgumentError
+        raise "Instance of #{error_klass} can't be initialized with no arguments"
+      end
+    end
+  end
+end