Introduce a new FactoriesInMigrationSpecs cop

Signed-off-by: Rémy Coutable <remy@rymai.me>

3 files changed, 53 insertions, 1 deletions

diff --git a/rubocop/cop/rspec/factories_in_migration_specs.rb b/rubocop/cop/rspec/factories_in_migration_specs.rb
new file mode 100644
index 00000000000..0c5aa838a2c
--- /dev/null
+++ b/rubocop/cop/rspec/factories_in_migration_specs.rb
@@ -0,0 +1,40 @@
+require_relative '../../spec_helpers'
+
+module RuboCop
+  module Cop
+    module RSpec
+      # This cop checks for the usage of factories in migration specs
+      #
+      # @example
+      #
+      #   # bad
+      #   let(:user) { create(:user) }
+      #
+      #   # good
+      #   let(:users) { table(:users) }
+      #   let(:user) { users.create!(name: 'User 1', username: 'user1') }
+      class FactoriesInMigrationSpecs < RuboCop::Cop::Cop
+        include SpecHelpers
+
+        MESSAGE = "Don't use FactoryBot.%s in migration specs, use `table` instead.".freeze
+        FORBIDDEN_METHODS = %i[build build_list create create_list].freeze
+
+        def_node_search :forbidden_factory_usage?, <<~PATTERN
+          (send {(const nil? :FactoryBot) nil?} {#{FORBIDDEN_METHODS.map(&:inspect).join(' ')}} ...)
+        PATTERN
+
+        # Following is what node.children looks like on a match:
+        # - Without FactoryBot namespace: [nil, :build, s(:sym, :user)]
+        # - With FactoryBot namespace: [s(:const, nil, :FactoryBot), :build, s(:sym, :user)]
+        def on_send(node)
+          return unless in_migration_spec?(node)
+          return unless forbidden_factory_usage?(node)
+
+          method = node.children[1]
+
+          add_offense(node, location: :expression, message: MESSAGE % method)
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb
index 0b4c7d31442..406ec95ffc9 100644
--- a/rubocop/rubocop.rb
+++ b/rubocop/rubocop.rb
@@ -21,4 +21,5 @@ require_relative 'cop/migration/update_column_in_batches'
 require_relative 'cop/migration/update_large_table'
 require_relative 'cop/project_path_helper'
 require_relative 'cop/rspec/env_assignment'
+require_relative 'cop/rspec/factories_in_migration_specs'
 require_relative 'cop/sidekiq_options_queue'
diff --git a/rubocop/spec_helpers.rb b/rubocop/spec_helpers.rb
index a702a083958..6c0f0193b1a 100644
--- a/rubocop/spec_helpers.rb
+++ b/rubocop/spec_helpers.rb
@@ -6,7 +6,18 @@ module RuboCop
     def in_spec?(node)
       path = node.location.expression.source_buffer.name
 
-      !SPEC_HELPERS.include?(File.basename(path)) && path.start_with?(File.join(Dir.pwd, 'spec'))
+      !SPEC_HELPERS.include?(File.basename(path)) &&
+        path.start_with?(File.join(Dir.pwd, 'spec'), File.join(Dir.pwd, 'ee', 'spec'))
+    end
+
+    # Returns true if the given node originated from a migration spec.
+    def in_migration_spec?(node)
+      path = node.location.expression.source_buffer.name
+
+      in_spec?(node) &&
+        path.start_with?(
+          File.join(Dir.pwd, 'spec', 'migrations'),
+          File.join(Dir.pwd, 'ee', 'spec', 'migrations'))
     end
   end
 end