Add Rails/HttpUrl cop to enforce passing a string literal as a URL to http method calls

For the test cases; to make the actual URL obvious and to facilitate tracking endpoint path changes.

Original discussion: rubocop/rails-style-guide#328

Signed-off-by: moznion <[email protected]>

Author: moznion

config/default.yml

@@ -565,6 +565,14 @@ Rails/HttpStatus:
     - numeric
     - symbolic
 
+Rails/HttpUrl:
+  Description: 'Enforces passing a string literal as a URL to http method calls.'
+  Enabled: true
+  VersionAdded: '2.26'
+  Include:
+    - 'spec/**/*'
+    - 'test/**/*'
+
 Rails/I18nLazyLookup:
   Description: 'Checks for places where I18n "lazy" lookup can be used.'
   StyleGuide: 'https://rails.rubystyle.guide/#lazy-lookup'

lib/rubocop/cop/rails/http_url.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Rails
+      # Enforces passing a string literal as a URL to http method calls.
+      #
+      # @example
+      #   # bad
+      #   get photos_path
+      #   put photo_path(id)
+      #   post edit_photo_path(id)
+      #
+      #   # good
+      #   get "/photos"
+      #   put "/photos/#{id}"
+      #   post "/photos/#{id}/edit"
+      class HttpUrl < Base
+        MSG = 'The first argument to `%<method>s` should be a string.'
+        RESTRICT_ON_SEND = %i[get post put patch delete head].freeze
+
+        def_node_matcher :request_method?, <<-PATTERN
+          (send nil? {#{RESTRICT_ON_SEND.map(&:inspect).join(' ')}} $!str ...)
+        PATTERN
+
+        def on_send(node)
+          request_method?(node) do |arg|
+            add_offense(arg, message: format(MSG, method: node.method_name))
+          end
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rails_cops.rb

@@ -61,6 +61,7 @@
 require_relative 'rails/has_many_or_has_one_dependent'
 require_relative 'rails/helper_instance_variable'
 require_relative 'rails/http_positional_arguments'
+require_relative 'rails/http_url'
 require_relative 'rails/http_status'
 require_relative 'rails/i18n_lazy_lookup'
 require_relative 'rails/i18n_locale_assignment'

spec/rubocop/cop/rails/http_url_spec.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Rails::HttpUrl, :config do
+  %i[get post put delete patch head].each do |http_method|
+    it "registers an offense when first argument to `#{http_method}` is not a string" do
+      padding = " #{' ' * http_method.length}"
+      expect_offense(<<~RUBY, http_method: http_method)
+        #{http_method} :resource
+        #{padding}^^^^^^^^^ The first argument to `#{http_method}` should be a string.
+      RUBY
+    end
+
+    it "does not register an offense when the first argument to #{http_method} is a string" do
+      expect_no_offenses(<<~RUBY)
+        #{http_method} '/resource'
+      RUBY
+    end
+  end
+end