Added Chewy/FieldType (#64)

* Added Chewy/FieldType

* Changelog

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 # main
 
+* Added cop `Chewy/FieldType`. ([#64](https://github.com/petalmd/rubocop-petal/pull/64))
 * Fix `Migration/ChangeTableReferences` offense location (Fix [#61](https://github.com/petalmd/rubocop-petal/issues/61)) ([#62](https://github.com/petalmd/rubocop-petal/pull/62))
 * Added cop `Sidekiq/NoEarlyNilReturn` ([#58](https://github.com/petalmd/rubocop-petal/pull/58))
 * Added cop `Rails/EnumStartingValue` ([#57](https://github.com/petalmd/rubocop-petal/pull/57))

config/default.yml

@@ -1,3 +1,9 @@
+Chewy/FieldType:
+  Description: 'Assure that a type is defined for a Chewy field.'
+  Enabled: true
+  Include:
+    - app/chewy/**/*
+
 Grape/PreferNamespace:
   Description: 'Prevent usage of namespace aliases.'
   Enabled: true

lib/rubocop/cop/chewy/field_type.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Chewy
+      # This cop force to specify a type for Chewy field
+      #
+      #   # bad
+      #   field :name
+      #
+      #   # good
+      #   field :name, type: 'text'
+      class FieldType < Base
+        MSG = 'Specify a `type` for Chewy field.'
+
+        RESTRICT_ON_SEND = %i[field].freeze
+
+        # @!method options_has_field?(node)
+        def_node_matcher :options_has_field?, <<~PATTERN
+          (send nil? :field (sym _)+ (hash <(pair (sym :type) {str sym}) ...>))
+        PATTERN
+
+        def on_send(node)
+          return if options_has_field?(node)
+
+          add_offense(node)
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/chewy/field_type_spec.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Chewy::FieldType, :config do
+  it 'registers an offense when no specifying a field' do
+    expect_offense(<<~RUBY)
+      field :name
+      ^^^^^^^^^^^ Specify a `type` for Chewy field.
+    RUBY
+
+    expect_offense(<<~RUBY)
+      field :name, value: 'text'
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^ Specify a `type` for Chewy field.
+    RUBY
+
+    expect_offense(<<~RUBY)
+      field :name, value: lambda { |a| a.name.upcase }
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Specify a `type` for Chewy field.
+    RUBY
+
+    expect_offense(<<~RUBY)
+      defined_type User do
+        field :name
+        ^^^^^^^^^^^ Specify a `type` for Chewy field.
+      end
+    RUBY
+
+    expect_offense(<<~RUBY)
+      field :name, :email
+      ^^^^^^^^^^^^^^^^^^^ Specify a `type` for Chewy field.
+    RUBY
+  end
+
+  it 'does not register an offense when a type is specified' do
+    expect_no_offenses(<<~RUBY)
+      field :name, type: 'text'
+    RUBY
+
+    expect_no_offenses(<<~RUBY)
+      field :name, type: :text
+    RUBY
+
+    expect_no_offenses(<<~RUBY)
+      field :name, :email, type: 'text'
+    RUBY
+  end
+end