Skip validations on legacy primary keys like we do for omakase 'id's. (joshwlewis#71)

Author: buermann

.gitignore

@@ -1,4 +1,5 @@
 .bundle/
+.byebug_history
 *.gem
 log/*.log
 pkg/

lib/validates_by_schema.rb

@@ -62,7 +62,7 @@ def schema_validatable_columns
     end
 
     def ignored_columns_for_validates_by_schema
-      ['id', 'created_at', 'updated_at', 'deleted_at']
+      [primary_key, 'created_at', 'updated_at', 'deleted_at']
     end
 
   end

spec/config/schema.rb

@@ -30,13 +30,15 @@
     t.boolean 'enabled'
     t.binary 'data'
     t.integer 'parent_id',                                           null: false
+    t.integer 'legacy_id',                                           null: false
     t.integer 'other_id'
     t.integer 'kind',                                                null: false
     t.string 'list', ENV['DB'] == 'postgresql' ? { array: true, limit: 3 } : {}
 
     t.index 'parent_id'
     t.index ['name', 'wheels'], unique: true
     t.index 'other_id', unique: true
+    t.index 'legacy_id', unique: true
     t.index ['doors'], unique: true, where: 'enabled = true'
     t.index ['model', 'price'], unique: true
     t.index ['model', 'cost'], unique: true

spec/support/models/legacy_contraption.rb

@@ -0,0 +1,7 @@
+require 'contraption'
+
+class LegacyContraption < Widget
+  self.primary_key = :legacy_id
+  self.clear_validators!
+  validates_by_schema # recalculate the validations
+end

spec/validations_spec.rb

@@ -20,6 +20,7 @@
       enabled: true,
       data: 'the question'.unpack('b*').to_s,
       parent: Widget.new,
+      legacy_id: 0,
       kind: 'one',
       list: ['abc']
     }
@@ -135,6 +136,15 @@
       end
     end
 
+    context 'legacy objects' do
+      subject { LegacyContraption.new attributes.merge(id: 1, legacy_id: nil) }
+
+      context 'should skip validations on a custom primary key while applying them to the ID' do
+        it { should validate_presence_of(:id) }
+        it { should_not validate_presence_of(:legacy_id) }
+      end
+    end
+
     context 'validates uniqueness' do
       let(:valid_attributes) do
         attrs = attributes.dup