Make ActiveRecordException descendants args optional

This change allows to instantiate all ActiveRecordError descendant
execption classes without arguments, which might be useful in testing
and is far less surprising than mandatory arguments.

4 files changed, 162 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