diff --git a/app/services/tasks/samples_to_repository_migration_service.rb b/app/services/tasks/samples_to_repository_migration_service.rb
index 3697ec5e6..6270bf296 100644
--- a/app/services/tasks/samples_to_repository_migration_service.rb
+++ b/app/services/tasks/samples_to_repository_migration_service.rb
@@ -1,110 +1,112 @@
-module Tasks::SamplesToRepositoryMigrationService
-  def self.prepare_repository(team, copy_num = 0)
-    repository = Repository.new(
-      name: copy_num > 0 ? "Samples (#{copy_num})" : 'Samples',
-      team: team,
-      created_by: team.created_by
-    )
-    return repository if repository.save
-    prepare_repository(team, copy_num += 1)
-  end
+module Tasks
+  module SamplesToRepositoryMigrationService
+    def self.prepare_repository(team, copy_num = 0)
+      repository = Repository.new(
+        name: copy_num > 0 ? "Samples (#{copy_num})" : 'Samples',
+        team: team,
+        created_by: team.created_by
+      )
+      return repository if repository.save
+      prepare_repository(team, copy_num += 1)
+    end
 
-  def self.prepare_text_value_custom_columns(team, repository)
-    custom_columns_sql = <<-SQL
-      SELECT * FROM custom_fields WHERE team_id = #{team.id}
-    SQL
-    # execute query
-    custom_columns = ActiveRecord::Base.connection.execute(custom_columns_sql)
+    def self.prepare_text_value_custom_columns(team, repository)
+      custom_columns_sql = <<-SQL
+        SELECT * FROM custom_fields WHERE team_id = #{team.id}
+      SQL
+      # execute query
+      custom_columns = ActiveRecord::Base.connection.execute(custom_columns_sql)
 
-    repository_columns = []
-    custom_columns.each_with_index do |column, index|
-      repository_column = RepositoryColumn.create(
+      repository_columns = []
+      custom_columns.each_with_index do |column, index|
+        repository_column = RepositoryColumn.create(
+          repository: repository,
+          created_by_id: column.fetch('user_id') { repository.created_by_id },
+          data_type: :RepositoryTextValue,
+          name: column.fetch('name') { "Custom column (#{index})" },
+          created_at: column.fetch('created_at') { DateTime.now },
+          updated_at: column.fetch('updated_at') { DateTime.now }
+        )
+        repository_columns << repository_column
+      end
+      repository_columns
+    end
+
+    def self.prepare_list_value_custom_columns_with_list_items(team, repository)
+      sample_types_sql = <<-SQL
+        SELECT name, created_by_id, last_modified_by_id
+        FROM sample_types
+        WHERE team_id = #{team.id}
+      SQL
+      sample_groups_sql = <<-SQL
+        SELECT name, created_by_id, last_modified_by_id
+        FROM sample_groups
+        WHERE team_id = #{team.id}
+      SQL
+      # execute query
+      sample_types = ActiveRecord::Base.connection.execute(sample_types_sql)
+      sample_groups = ActiveRecord::Base.connection.execute(sample_groups_sql)
+
+      repository_columns = []
+
+      repository_columns << RepositoryColumn.create(
         repository: repository,
-        created_by_id: column.fetch('user_id') { repository.created_by_id },
-        data_type: :RepositoryTextValue,
-        name: column.fetch('name') { "Custom column (#{index})" },
-        created_at: column.fetch('created_at') { DateTime.now },
-        updated_at: column.fetch('updated_at') { DateTime.now }
+        created_by_id: repository.created_by_id,
+        data_type: :RepositoryListValue,
+        name: 'Sample group'
       )
-      repository_columns << repository_column
-    end
-    repository_columns
-  end
 
-  def self.prepare_list_value_custom_columns_with_list_items(team, repository)
-    sample_types_sql = <<-SQL
-      SELECT name, created_by_id, last_modified_by_id
-      FROM sample_types
-      WHERE team_id = #{team.id}
-    SQL
-    sample_groups_sql = <<-SQL
-      SELECT name, created_by_id, last_modified_by_id
-      FROM sample_groups
-      WHERE team_id = #{team.id}
-    SQL
-    # execute query
-    sample_types = ActiveRecord::Base.connection.execute(sample_types_sql)
-    sample_groups = ActiveRecord::Base.connection.execute(sample_groups_sql)
-
-    repository_columns = []
-
-    repository_columns << RepositoryColumn.create(
-      repository: repository,
-      created_by_id: repository.created_by_id,
-      data_type: :RepositoryListValue,
-      name: 'Sample group'
-    )
-
-    repository_columns << RepositoryColumn.create(
-      repository: repository,
-      created_by_id: repository.created_by_id,
-      data_type: :RepositoryListValue,
-      name: 'Sample type'
-    )
-
-    sample_groups.each_with_index do |item, index|
-      RepositoryListItem.create(
-        data: item.fetch('name') { "sample group item (#{index})" },
-        created_by_id: item.fetch('created_by_id') { team.created_by_id },
-        last_modified_by_id: item.fetch('last_modified_by_id') { team.created_by_id },
-        repository_column: repository_columns.first,
-        repository: repository
+      repository_columns << RepositoryColumn.create(
+        repository: repository,
+        created_by_id: repository.created_by_id,
+        data_type: :RepositoryListValue,
+        name: 'Sample type'
       )
+
+      sample_groups.each_with_index do |item, index|
+        RepositoryListItem.create(
+          data: item.fetch('name') { "sample group item (#{index})" },
+          created_by_id: item.fetch('created_by_id') { team.created_by_id },
+          last_modified_by_id: item.fetch('last_modified_by_id') { team.created_by_id },
+          repository_column: repository_columns.first,
+          repository: repository
+        )
+      end
+
+      sample_types.each_with_index do |item, index|
+        RepositoryListItem.create(
+          data: item.fetch('name') { "sample group item (#{index})" },
+          created_by_id: item.fetch('created_by_id') { team.created_by_id },
+          last_modified_by_id: item.fetch('last_modified_by_id') { team.created_by_id },
+          repository_column: repository_columns.last,
+          repository: repository
+        )
+      end
+
+      repository_columns
     end
 
-    sample_types.each_with_index do |item, index|
-      RepositoryListItem.create(
-        data: item.fetch('name') { "sample group item (#{index})" },
-        created_by_id: item.fetch('created_by_id') { team.created_by_id },
-        last_modified_by_id: item.fetch('last_modified_by_id') { team.created_by_id },
-        repository_column: repository_columns.last,
-        repository: repository
-      )
+    def self.get_sample_custom_fields(sample_id)
+      custom_sample_fields_sql = <<-SQL
+        SELECT custom_fields.name AS column_name_reference,
+               sample_custom_fields.value,
+               sample_custom_fields.created_at,
+               sample_custom_fields.updated_at
+        FROM custom_fields
+        INNER JOIN sample_custom_fields
+        ON custom_fields.id = sample_custom_fields.custom_field_id
+        WHERE sample_custom_fields.sample_id = #{sample_id}
+      SQL
+      ActiveRecord::Base.connection.execute(custom_sample_fields_sql).to_a
     end
 
-    repository_columns
-  end
-
-  def self.get_sample_fields(sample_id)
-    custom_sample_fields_sql = <<-SQL
-      SELECT custom_fields.name AS column_name_reference,
-             sample_custom_fields.value,
-             sample_custom_fields.created_at,
-             sample_custom_fields.updated_at
-      FROM custom_fields
-      INNER JOIN sample_custom_fields
-      ON custom_fields.id = sample_custom_fields.custom_field_id
-      WHERE sample_custom_fields.sample_id = #{sample_id}
-    SQL
-    ActiveRecord::Base.connection.execute(custom_sample_fields_sql)
-  end
-
-  def self.get_assigned_sample_module(sample_id)
-    assigned_samples_sql = <<-SQL
-      SELECT my_module_id, assigned_by_id, assigned_on
-      FROM sample_my_modules
-      WHERE sample_my_modules.sample_id = #{sample_id}
-    SQL
-    ActiveRecord::Base.connection.execute(assigned_samples_sql)
+    def self.get_assigned_sample_module(sample_id)
+      assigned_samples_sql = <<-SQL
+        SELECT my_module_id, assigned_by_id, assigned_on
+        FROM sample_my_modules
+        WHERE sample_my_modules.sample_id = #{sample_id}
+      SQL
+      ActiveRecord::Base.connection.execute(assigned_samples_sql).to_a
+    end
   end
 end
diff --git a/spec/factories/sample_custom_field.rb b/spec/factories/sample_custom_field.rb
new file mode 100644
index 000000000..c0bf9ddfa
--- /dev/null
+++ b/spec/factories/sample_custom_field.rb
@@ -0,0 +1,5 @@
+FactoryBot.define do
+  factory :sample_custom_field do
+    value 'Sample 111'
+  end
+end
diff --git a/spec/services/tasks/samples_to_repository_migration_service_spec.rb b/spec/services/tasks/samples_to_repository_migration_service_spec.rb
index 3718d001e..ad9241e0f 100644
--- a/spec/services/tasks/samples_to_repository_migration_service_spec.rb
+++ b/spec/services/tasks/samples_to_repository_migration_service_spec.rb
@@ -2,32 +2,240 @@ require 'rails_helper'
 
 describe Tasks::SamplesToRepositoryMigrationService do
   let(:user) { create :user, email: 'happy.user@scinote.net' }
-  let(:team) { create :team, created_by: :user }
+  let(:team) { create :team, created_by: user }
   let(:user_team) { create :user_team, user: user, team: team }
-  let(:sample) { create :sample, name: 'my sample', user: user, team: team }
+  let(:sample) { create :sample, name: 'My sample', user: user, team: team }
 
   describe '#prepare_repository/2' do
-    it 'creates and return a new custom repository named "Samples" for team' do
-      repository = SamplesToRepositoryMigrationService.prepare_repository(team)
-      expect(repository).to be_an_instance_of(Repository)
-      expect(repository.team).to eq team
-      expect(repository.name).to eq 'Samples'
+    context 'creates and return a new custom repository named' do
+      it '"Samples" for team' do
+        repository = Tasks::SamplesToRepositoryMigrationService
+                     .prepare_repository(team)
+        expect(repository).to be_an_instance_of(Repository)
+        expect(repository.team).to eq team
+        expect(repository.name).to eq 'Samples'
+      end
+
+      it '"Samples (1)" if repository name "Samples" already exists' do
+        create :repository, name: 'Samples', team: team, created_by: user
+        repository = Tasks::SamplesToRepositoryMigrationService
+                     .prepare_repository(team)
+        expect(repository).to be_an_instance_of(Repository)
+        expect(repository.team).to eq team
+        expect(repository.name).to eq 'Samples (1)'
+      end
     end
   end
 
   describe '#prepare_text_value_custom_columns/2' do
+    let(:repository) do
+      create :repository, name: 'Samples', team: team, created_by: user
+    end
+    let(:subject) do
+      Tasks::SamplesToRepositoryMigrationService
+        .prepare_text_value_custom_columns(team, repository)
+    end
 
+    context 'custom columns exists' do
+      before do
+        create :samples_table, user: user, team: team
+        10.times do |index|
+          create :custom_field, name: "My Custom field (#{index})",
+                                user: user,
+                                team: team,
+                                last_modified_by: user
+        end
+      end
+
+      it { is_expected.to be_an Array }
+      it { expect(subject.length).to eq 10 }
+      it { expect(subject.first.name).to eq 'My Custom field (0)' }
+      it { expect(subject.last.name).to eq 'My Custom field (9)' }
+      it { expect(subject.first).to be_an_instance_of RepositoryColumn }
+      it { expect(subject.first.data_type).to eq 'RepositoryTextValue' }
+      it { expect(subject.first.repository).to eq repository }
+    end
+
+    context 'custom columns does not exists' do
+      it { is_expected.to be_an Array }
+      it { is_expected.to be_empty }
+    end
   end
 
   describe '#prepare_list_value_custom_columns_with_list_items/2' do
+    let(:repository) do
+      create :repository, name: 'Samples', team: team, created_by: user
+    end
+    let(:subject) do
+      Tasks::SamplesToRepositoryMigrationService
+        .prepare_list_value_custom_columns_with_list_items(team, repository)
+    end
 
+    context 'with samples types' do
+      before do
+        10.times do |index|
+          create :sample_type, name: "Sample Type Item (#{index})",
+                               team: team,
+                               created_by: user,
+                               last_modified_by: user
+        end
+      end
+
+      it { is_expected.to be_an Array }
+      it { expect(subject.length).to eq 2 }
+      it { expect(subject.first).to be_an_instance_of(RepositoryColumn) }
+      it { expect(subject.first.name).to eq 'Sample group' }
+      it { expect(subject.first.data_type).to eq 'RepositoryListValue' }
+      it { expect(subject.last.name).to eq 'Sample type' }
+      it { expect(subject.last.data_type).to eq 'RepositoryListValue' }
+
+      describe 'generated list items from sample types' do
+        let!(:generated_list_items) { subject.last.repository_list_items }
+        it { expect(generated_list_items.count).to eq 10 }
+
+        it 'has generated list_items with similar properties' do
+          generated_list_items.each_with_index do |item, index|
+            expect(item.data).to eq "Sample Type Item (#{index})"
+            expect(item).to be_an_instance_of RepositoryListItem
+            expect(item.created_by).to eq user
+            expect(item.last_modified_by).to eq user
+          end
+        end
+      end
+    end
+
+    context 'with samples groups' do
+      before do
+        10.times do |index|
+          create :sample_group, name: "Sample Group Item (#{index})",
+                                color: '#000000',
+                                team: team,
+                                created_by: user,
+                                last_modified_by: user
+        end
+      end
+
+      it { is_expected.to be_an Array }
+      it { expect(subject.length).to eq 2 }
+      it { expect(subject.first).to be_an_instance_of(RepositoryColumn) }
+      it { expect(subject.last).to be_an_instance_of(RepositoryColumn) }
+      it { expect(subject.first.name).to eq 'Sample group' }
+      it { expect(subject.first.data_type).to eq 'RepositoryListValue' }
+      it { expect(subject.last.name).to eq 'Sample type' }
+      it { expect(subject.last.data_type).to eq 'RepositoryListValue' }
+
+      describe 'generated list items from sample groups' do
+        let!(:generated_list_items) { subject.first.repository_list_items }
+        it { expect(generated_list_items.count).to eq 10 }
+
+        it 'has generated list_items with similar properties' do
+          generated_list_items.each_with_index do |item, index|
+            expect(item.data).to eq "Sample Group Item (#{index})"
+            expect(item).to be_an_instance_of RepositoryListItem
+            expect(item.created_by).to eq user
+            expect(item.last_modified_by).to eq user
+          end
+        end
+      end
+    end
   end
 
-  describe '#get_sample_fields/1' do
+  describe '#get_sample_custom_fields/1' do
+    let(:custom_field) do
+      create :custom_field, name: 'My Custom column',
+                            user: user,
+                            team: team,
+                            last_modified_by: user
+    end
 
+    let(:subject) do
+      Tasks::SamplesToRepositoryMigrationService
+        .get_sample_custom_fields(sample.id)
+    end
+    context 'sample has custom column assigned' do
+      before do
+        create :samples_table, user: user, team: team
+        create :sample_custom_field, value: 'field value',
+                                     custom_field: custom_field,
+                                     sample: sample
+      end
+
+      it 'returns a hash of sample values' do
+        element = subject.first
+        is_expected.to be_an Array
+        expect(subject.length).to eq 1
+        expect(element.fetch('column_name_reference')).to eq 'My Custom column'
+        expect(element.fetch('value')).to eq 'field value'
+        expect(element.fetch('created_at')).to be_present
+        expect(element.fetch('updated_at')).to be_present
+      end
+    end
+
+    context 'sample does not have custom columns assigned' do
+      it { is_expected.to be_an Array }
+      it { is_expected.to be_empty }
+    end
   end
 
   describe '#get_assigned_sample_module/1' do
+    let(:my_module) { create :my_module }
+    let(:subject) do
+      Tasks::SamplesToRepositoryMigrationService
+        .get_assigned_sample_module(sample.id)
+    end
 
+    context 'sample is assigned to one module' do
+      let!(:sample_my_module) do
+        create :sample_my_module, sample: sample,
+                                  my_module: my_module,
+                                  assigned_by: user
+      end
+
+      it { is_expected.to be_an Array }
+      it { expect(subject.length).to eq 1 }
+      it 'returnes assigned my_module data' do
+        my_module_data = subject.first
+        expect(
+          my_module_data.fetch('my_module_id')
+        ).to eq sample_my_module.my_module_id
+        expect(
+          my_module_data.fetch('assigned_by_id')
+        ).to eq sample_my_module.assigned_by_id
+        expect(
+          my_module_data.fetch('assigned_on')
+        ).to eq sample_my_module.assigned_on
+      end
+    end
+
+    context 'sample is not assigned to module' do
+      it { is_expected.to be_an Array }
+      it { is_expected.to be_empty }
+    end
+
+    context 'sample is assigned to multiple modules' do
+      before do
+        @modules_ids = []
+        10.times do |index|
+          my_module = create :my_module, name: "My module (#{index})"
+          @modules_ids << my_module.id
+        end
+        10.times do |index|
+          create :sample_my_module,
+                 sample: sample,
+                 my_module_id: @modules_ids[index],
+                 assigned_by: user
+        end
+      end
+
+      it { is_expected.to be_an Array }
+      it { expect(subject.length).to eq 10 }
+
+      it 'is expected to return an array of samples_my_modules data' do
+        subject.each do |element|
+          expect(@modules_ids).to include(element.fetch('my_module_id').to_i)
+          expect(element.fetch('assigned_by_id')).to eq user.id
+        end
+      end
+    end
   end
 end