Module: ConcernsOnRails::Support::ColumnGuard

Included in:
Models::Addressable::ClassMethods, Models::Aliasable::ClassMethods, Models::Anonymizable::ClassMethods, Models::Auditable::ClassMethods, Models::CounterCacheable::ClassMethods, Models::Duplicable::ClassMethods, Models::Encryptable::ClassMethods, Models::Lockable::ClassMethods, Models::SoftDeletable::ClassMethods, Models::Sortable::ClassMethods, Models::Stateable::ClassMethods, Models::Storable::ClassMethods, Models::Taggable::ClassMethods
Defined in:
lib/concerns_on_rails/support/column_guard.rb

Overview

Shared schema-validation helper mixed into a concern's ClassMethods. Runs in class context, so column_names / table_name resolve against the including model. Centralizes the column-existence check that every model concern used to re-implement, and keeps the error wording uniform.

class_methods do
include ConcernsOnRails::Support::ColumnGuard

def activatable_by(field = :active)
  self.activatable_field = field.to_sym
  ensure_columns!("ConcernsOnRails::Models::Activatable", activatable_field)
end
end

When the schema is unreachable — no database yet (db:create, a fresh db:migrate, assets:precompile, CI bootstrap) or the table not yet migrated — the check is skipped and false is returned instead of raising, so model classes stay loadable. A missing column with a reachable schema still raises: the rescue is scoped to ActiveRecord::ActiveRecordError precisely so real bugs (NameError from a typo etc.) keep surfacing. Skipping is self-healing: once the migration runs and classes reload, validation happens for real — and a genuinely missing column still fails loudly on first query.

The phrase "does not exist" is preserved so existing specs that match /does not exist/ keep passing.

Instance Method Summary collapse

Instance Method Details

#column_migration_hint(klass, field, types) ⇒ Object

" Add it with: bin/rails generate migration AddDeletedAtToArticles deleted_at:datetime" — every missing-column failure becomes a copy-paste fix. Without a known type the column name goes out bare (the generator defaults to string).



60
61
62
63
64
65
 
# File 'lib/concerns_on_rails/support/column_guard.rb', line 60

def column_migration_hint(klass, field, types)
  type = types.is_a?(Hash) ? types[field.to_sym] : types
  column = [field, type].compact.join(":")
  " Add it with: bin/rails generate migration " \
    "Add#{field.to_s.camelize}To#{klass.table_name.to_s.camelize} #{column}"
end

#ensure_columns!(concern, *fields, types: nil) ⇒ Object

types: teaches the error message: a Symbol/String applies to every listed field, a Hash maps field => type. When present, the raised ArgumentError appends a ready-to-paste migration command. Generator column-modifier syntax is welcome ("string:uniq" — tokens/slugs want a unique index anyway).



37
38
39
 
# File 'lib/concerns_on_rails/support/column_guard.rb', line 37

def ensure_columns!(concern, *fields, types: nil)
  ensure_columns_on!(concern, self, *fields, types: types)
end

#ensure_columns_on!(concern, klass, *fields, types: nil) ⇒ Object

Same contract, validated against another class (e.g. CounterCacheable checks the counter column on the parent model).



43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/concerns_on_rails/support/column_guard.rb', line 43

def ensure_columns_on!(concern, klass, *fields, types: nil)
  return false unless schema_reachable?(klass)

  fields.flatten.compact.each do |field|
    next if klass.column_names.include?(field.to_s)

    raise ArgumentError,
          "#{concern}: '#{field}' does not exist in the database (table: #{klass.table_name})." \
          "#{column_migration_hint(klass, field, types)}"
  end
  true
end

#schema_reachable?(klass = self) ⇒ Boolean

True when the class's table can actually be inspected. Connection errors (ConnectionNotEstablished, NoDatabaseError, adapter errors) all inherit from ActiveRecord::ActiveRecordError.

Returns:

  • (Boolean) 


70
71
72
73
74
 
# File 'lib/concerns_on_rails/support/column_guard.rb', line 70

def schema_reachable?(klass = self)
  klass.table_exists?
rescue ActiveRecord::ActiveRecordError
  false
end