Change table (#48)

* ci: Update .deepsource.toml

* create migrations for renaming and removing

* handle renaming columns

* fix

* convert to sym

* update version

* remove pp

---------

Co-authored-by: deepsource-totalanarchy[bot] <107136100+deepsource-totalanarchy[bot]@users.noreply.github.com>

lib/trains/utils/migration_tailor.rb

@@ -1,5 +1,8 @@
+# frozen_string_literal: true
+
 module Trains
   module Utils
+    # Combine multiple migrations into models
     module MigrationTailor
       def self.stitch(models = {}, migrations)
         migrations.each do |mig|
@@ -22,8 +25,46 @@ def self.stitch(models = {}, migrations)
                 field.name == mig.fields.first.name
               end
             models[mig.table_name].fields.delete(column)
+          when :rename_column
+            column =
+              models[mig.table_name].fields.find do |field|
+                field.name == mig.fields.first.name
+              end
+            models[mig.table_name].fields.push(
+              Trains::DTO::Field.new(
+                name: mig.fields.first.type.to_sym,
+                type: column.type
+              )
+            )
+            models[mig.table_name].fields.delete(column)
           when :change_table
-          # TODO: handle renaming columns
+            mig.fields.each do |field|
+              case field.type
+              when :remove
+                column =
+                  models[mig.table_name].fields.find do |mod_field|
+                    mod_field.name == field.name
+                  end
+                models[mig.table_name].fields.delete(column)
+              when :rename
+                # find the field and store temporarily
+                column =
+                  models[mig.table_name].fields.find do |mod_field|
+                    mod_field.name == field.name[0]
+                  end
+                # Create new field from temp with new name
+                models[mig.table_name].fields.push(
+                  Trains::DTO::Field.new(
+                    name: field.name[1],
+                    type: column.type
+                  )
+                )
+                # Delete the field
+                models[mig.table_name].fields.delete(column)
+              else
+                models[mig.table_name].fields.push(field)
+              end
+            end
           when :change_column
             # get column
             column =
@@ -34,6 +75,8 @@ def self.stitch(models = {}, migrations)
             models[mig.table_name].fields.delete(column)
 
             models[mig.table_name].fields << mig.fields.first
+          else
+            next
           end
 
         rescue NoMethodError

lib/trains/version.rb

@@ -1,3 +1,3 @@
 module Trains
-  VERSION = '0.0.18'.freeze
+  VERSION = '0.0.19'.freeze
 end

lib/trains/visitor/migration.rb

@@ -22,6 +22,7 @@ class Migration < Base
         add_column_with_default
         change_column
         add_reference
+        rename_column
         remove_column
       ].freeze
 
@@ -181,7 +182,11 @@ def parse_migration_field(node)
           # t.references
           type = :bigint
           value = "#{node.children[2].value}_id".to_sym
-          fields << DTO::Field.new(value.to_sym, type)
+          fields << DTO::Field.new(value, type)
+        when :rename
+          type = :rename
+          value = node.children[2..3].map { |field| field.value.to_sym }
+          fields << DTO::Field.new(value, type)
         when :index
         else
           # t.string, t.integer etc.

lib/trains/visitor/model.rb

@@ -35,7 +35,7 @@ def parse_model(node)
         @result << DTO::Migration.new(
           @model_class,
           :add_column,
-          [DTO::Field.new(node.arguments.first.value, :bigint)],
+          [DTO::Field.new(node.arguments.first.value.to_sym, :bigint)],
           nil
         )
 

spec/fixtures/change_table.rb

@@ -0,0 +1,19 @@
+class ChangeTable < ActiveRecord::Migration[7.0]
+  def change
+    create_table :groups do |t|
+      t.string :title
+
+      t.timestamps
+    end
+    add_column :groups, :name, :string
+    add_index :groups, :title, unique: true
+
+    change_table :groups do |t|
+      t.remove :title
+      t.rename :name, :whatup
+    end
+
+    rename_column :groups, :whatup, :name
+    remove_column :groups, :name
+  end
+end

spec/lib/trains/utils/migration_tailor_spec.rb

@@ -7,7 +7,7 @@
         'Post' => Trains::DTO::Model.new(
           name: 'Post',
           fields: [
-            Trains::DTO::Field.new(:name, :string),
+            Trains::DTO::Field.new(:name, :string)
           ],
           version: 6.3
         )
@@ -36,7 +36,8 @@
     end
 
     it 'creates a model and adds a column to it' do
-      models = Trains::Utils::MigrationTailor.stitch(models_from_schema, create_add_migs)
+      models = Trains::Utils::MigrationTailor.stitch(models_from_schema,
+                                                     create_add_migs)
       expect(models).to eq(
         {
           'Post' =>
@@ -135,4 +136,75 @@
       )
     end
   end
+
+  context 'Given migrations with rename and remove column' do
+    let(:migs_with_rename) do
+      [
+        Trains::DTO::Migration.new(
+          table_name: 'Group',
+          modifier: :create_table,
+          fields: [
+            Trains::DTO::Field.new(:id, :bigint),
+            Trains::DTO::Field.new(:title, :string),
+            Trains::DTO::Field.new(:age, :integer),
+            Trains::DTO::Field.new(:created_at, :datetime),
+            Trains::DTO::Field.new(:updated_at, :datetime)
+          ],
+          version: 7.0
+        ),
+        Trains::DTO::Migration.new(
+          table_name: 'Group',
+          modifier: :add_column,
+          fields: [
+            Trains::DTO::Field.new(:name, :string)
+          ],
+          version: 7.0
+        ),
+        Trains::DTO::Migration.new(
+          table_name: 'Group',
+          modifier: :change_table,
+          fields: [
+            Trains::DTO::Field.new(:title, :remove),
+            Trains::DTO::Field.new(%i[name whatup], :rename)
+          ],
+          version: 7.0
+        ),
+        Trains::DTO::Migration.new(
+          table_name: 'Group',
+          modifier: :rename_column,
+          fields: [
+            Trains::DTO::Field.new(:age, :alive_since)
+          ],
+          version: 7.0
+        ),
+        Trains::DTO::Migration.new(
+          table_name: 'Group',
+          modifier: :rename_column,
+          fields: [
+            Trains::DTO::Field.new(:whatup, :name)
+          ],
+          version: 7.0
+        )
+      ]
+    end
+
+    it 'generates models with renamed fields' do
+      models = Trains::Utils::MigrationTailor.stitch(migs_with_rename)
+      expect(models).to eq(
+        {
+          'Group' => Trains::DTO::Model.new(
+            name: 'Group',
+            version: 7.0,
+            fields: [
+              Trains::DTO::Field.new(:id, :bigint),
+              Trains::DTO::Field.new(:created_at, :datetime),
+              Trains::DTO::Field.new(:updated_at, :datetime),
+              Trains::DTO::Field.new(:alive_since, :integer),
+              Trains::DTO::Field.new(:name, :string)
+            ]
+          )
+        }
+      )
+    end
+  end
 end

spec/lib/trains/visitor/migration_spec.rb

@@ -31,6 +31,10 @@
     File.expand_path "#{__FILE__}/../../../../fixtures/safety_assured.rb"
   end
 
+  let(:change_table) do
+    File.expand_path "#{__FILE__}/../../../../fixtures/change_table.rb"
+  end
+
   context 'Given a valid DB migration file path' do
     it 'returns an object with its metadata' do
       parser = described_class.new
@@ -298,4 +302,65 @@
       end
     end
   end
+
+  context 'Give a migration containing change_table migration' do
+    it 'create the appropriate migration objects' do
+      parser = described_class.new
+      file_ast =
+        RuboCop::AST::ProcessedSource.from_file(
+          change_table,
+          RUBY_VERSION.to_f
+        ).ast
+      file_ast.each_node { |node| parser.process(node) }
+
+      expect(parser.result).to eq(
+        [
+          Trains::DTO::Migration.new(
+            table_name: 'Group',
+            modifier: :create_table,
+            fields: [
+              Trains::DTO::Field.new(:id, :bigint),
+              Trains::DTO::Field.new(:title, :string),
+              Trains::DTO::Field.new(:created_at, :datetime),
+              Trains::DTO::Field.new(:updated_at, :datetime)
+            ],
+            version: 7.0
+          ),
+          Trains::DTO::Migration.new(
+            table_name: 'Group',
+            modifier: :add_column,
+            fields: [
+              Trains::DTO::Field.new(:name, :string)
+            ],
+            version: 7.0
+          ),
+          Trains::DTO::Migration.new(
+            table_name: 'Group',
+            modifier: :change_table,
+            fields: [
+              Trains::DTO::Field.new(:title, :remove),
+              Trains::DTO::Field.new(%i[name whatup], :rename)
+            ],
+            version: 7.0
+          ),
+          Trains::DTO::Migration.new(
+            table_name: 'Group',
+            modifier: :rename_column,
+            fields: [
+              Trains::DTO::Field.new(:whatup, :name)
+            ],
+            version: 7.0
+          ),
+          Trains::DTO::Migration.new(
+            table_name: 'Group',
+            modifier: :remove_column,
+            fields: [
+              Trains::DTO::Field.new(:name, nil)
+            ],
+            version: 7.0
+          )
+        ]
+      )
+    end
+  end
 end