Automatically install ruby-lsp-rails as part of custom bundle

lib/ruby_lsp/setup_bundler.rb

@@ -57,15 +57,18 @@ def initialize(project_path, **options)
     def setup!
       raise BundleNotLocked if @gemfile&.exist? && !@lockfile&.exist?
 
-      # Do not setup a custom bundle if both `ruby-lsp` and `debug` are already in the Gemfile
-      if @dependencies["ruby-lsp"] && @dependencies["debug"]
+      # Do not set up a custom bundle if LSP dependencies are already in the Gemfile
+      if @dependencies["ruby-lsp"] &&
+          @dependencies["debug"] &&
+          (@dependencies["rails"] ? @dependencies["ruby-lsp-rails"] : true)
         $stderr.puts(
-          "Ruby LSP> Skipping custom bundle setup since both `ruby-lsp` and `debug` are already in #{@gemfile}",
+          "Ruby LSP> Skipping custom bundle setup since LSP dependencies are already in #{@gemfile}",
         )
 
-        # If the user decided to add the `ruby-lsp` and `debug` to their Gemfile after having already run the Ruby LSP,
-        # then we need to remove the `.ruby-lsp` folder, otherwise we will run `bundle install` for the top level and
-        # try to execute the Ruby LSP using the custom bundle, which will fail since the gems are not installed there
+        # If the user decided to add `ruby-lsp` and `debug` (and potentially `ruby-lsp-rails`) to their Gemfile after
+        # having already run the Ruby LSP, then we need to remove the `.ruby-lsp` folder, otherwise we will run `bundle
+        # install` for the top level and try to execute the Ruby LSP using the custom bundle, which will fail since the
+        # gems are not installed there
         @custom_dir.rmtree if @custom_dir.exist?
         return run_bundle_install
       end
@@ -143,6 +146,10 @@ def write_custom_gemfile
         parts << 'gem "debug", require: false, group: :development, platforms: :mri'
       end
 
+      if @dependencies["rails"] && !@dependencies["ruby-lsp-rails"]
+        parts << 'gem "ruby-lsp-rails", require: false, group: :development'
+      end
+
       content = parts.join("\n")
       @custom_gemfile.write(content) unless @custom_gemfile.exist? && @custom_gemfile.read == content
     end
@@ -183,22 +190,24 @@ def run_bundle_install(bundle_gemfile = @gemfile)
       local_config_path = File.join(Dir.pwd, ".bundle")
       env["BUNDLE_APP_CONFIG"] = local_config_path if Dir.exist?(local_config_path)
 
-      # If both `ruby-lsp` and `debug` are already in the Gemfile, then we shouldn't try to upgrade them or else we'll
-      # produce undesired source control changes. If the custom bundle was just created and either `ruby-lsp` or `debug`
-      # weren't a part of the Gemfile, then we need to run `bundle install` for the first time to generate the
-      # Gemfile.lock with them included or else Bundler will complain that they're missing. We can only update if the
-      # custom `.ruby-lsp/Gemfile.lock` already exists and includes both gems
+      # If `ruby-lsp` and `debug` (and potentially `ruby-lsp-rails`) are already in the Gemfile, then we shouldn't try
+      # to upgrade them or else we'll produce undesired source control changes. If the custom bundle was just created
+      # and any of `ruby-lsp`, `ruby-lsp-rails` or `debug` weren't a part of the Gemfile, then we need to run `bundle
+      # install` for the first time to generate the Gemfile.lock with them included or else Bundler will complain that
+      # they're missing. We can only update if the custom `.ruby-lsp/Gemfile.lock` already exists and includes all gems
 
       # When not updating, we run `(bundle check || bundle install)`
       # When updating, we run `((bundle check && bundle update ruby-lsp debug) || bundle install)`
       command = +"(bundle check"
 
       if should_bundle_update?
-        # If ruby-lsp or debug are not in the Gemfile, try to update them to the latest version
+        # If any of `ruby-lsp`, `ruby-lsp-rails` or `debug` are not in the Gemfile, try to update them to the latest
+        # version
         command.prepend("(")
         command << " && bundle update "
         command << "ruby-lsp " unless @dependencies["ruby-lsp"]
         command << "debug " unless @dependencies["debug"]
+        command << "ruby-lsp-rails " if @dependencies["rails"] && !@dependencies["ruby-lsp-rails"]
         command << "--pre" if @experimental
         command.delete_suffix!(" ")
         command << ")"
@@ -221,13 +230,20 @@ def run_bundle_install(bundle_gemfile = @gemfile)
 
     sig { returns(T::Boolean) }
     def should_bundle_update?
-      # If both `ruby-lsp` and `debug` are in the Gemfile, then we shouldn't try to upgrade them or else it will produce
-      # version control changes
-      return false if @dependencies["ruby-lsp"] && @dependencies["debug"]
+      # If `ruby-lsp`, `ruby-lsp-rails` and `debug` are in the Gemfile, then we shouldn't try to upgrade them or else it
+      # will produce version control changes
+      if @dependencies["rails"]
+        return false if @dependencies.values_at("ruby-lsp", "ruby-lsp-rails", "debug").all?
+
+        # If the custom lockfile doesn't include `ruby-lsp`, `ruby-lsp-rails` or `debug`, we need to run bundle install
+        # before updating
+        return false if custom_bundle_dependencies.values_at("ruby-lsp", "debug", "ruby-lsp-rails").any?(&:nil?)
+      else
+        return false if @dependencies.values_at("ruby-lsp", "debug").all?
 
-      # If the custom lockfile doesn't include either the `ruby-lsp` or `debug`, we need to run bundle install before
-      # updating
-      return false if custom_bundle_dependencies["ruby-lsp"].nil? || custom_bundle_dependencies["debug"].nil?
+        # If the custom lockfile doesn't include `ruby-lsp` or `debug`, we need to run bundle install before updating
+        return false if custom_bundle_dependencies.values_at("ruby-lsp", "debug").any?(&:nil?)
+      end
 
       # If the last updated file doesn't exist or was updated more than 4 hours ago, we should update
       !@last_updated_path.exist? || Time.parse(@last_updated_path.read) < (Time.now - FOUR_HOURS)

test/setup_bundler_test.rb

@@ -12,6 +12,18 @@ def test_does_nothing_if_both_ruby_lsp_and_debug_are_in_the_bundle
     refute_path_exists(".ruby-lsp")
   end
 
+  def test_does_nothing_if_both_ruby_lsp_and_debug_are_in_the_bundle2
+    Object.any_instance.expects(:system).with(bundle_env, "(bundle check || bundle install) 1>&2")
+    Bundler::LockfileParser.any_instance.expects(:dependencies).returns({
+      "ruby-lsp" => true,
+      "rails" => true,
+      "ruby-lsp-rails" => true,
+      "debug" => true,
+    })
+    run_script
+    refute_path_exists(".ruby-lsp")
+  end
+
   def test_removes_ruby_lsp_folder_if_both_gems_were_added_to_the_bundle
     Object.any_instance.expects(:system).with(bundle_env, "(bundle check || bundle install) 1>&2")
     Bundler::LockfileParser.any_instance.expects(:dependencies).returns({ "ruby-lsp" => true, "debug" => true })
@@ -22,6 +34,27 @@ def test_removes_ruby_lsp_folder_if_both_gems_were_added_to_the_bundle
     FileUtils.rm_r(".ruby-lsp") if Dir.exist?(".ruby-lsp")
   end
 
+  def test_in_a_rails_app_does_nothing_if_ruby_lsp_and_ruby_lsp_rails_and_debug_are_in_the_bundle
+    Object.any_instance.expects(:system).with(bundle_env, "(bundle check || bundle install) 1>&2")
+    Bundler::LockfileParser.any_instance.expects(:dependencies)
+      .returns({ "ruby-lsp" => true, "ruby-lsp-rails" => true, "debug" => true })
+    run_script
+    refute_path_exists(".ruby-lsp")
+  ensure
+    FileUtils.rm_r(".ruby-lsp") if Dir.exist?(".ruby-lsp")
+  end
+
+  def test_in_a_rails_app_removes_ruby_lsp_folder_if_all_gems_were_added_to_the_bundle
+    Object.any_instance.expects(:system).with(bundle_env, "(bundle check || bundle install) 1>&2")
+    Bundler::LockfileParser.any_instance.expects(:dependencies)
+      .returns({ "ruby-lsp" => true, "ruby-lsp-rails" => true, "debug" => true })
+    FileUtils.mkdir(".ruby-lsp")
+    run_script
+    refute_path_exists(".ruby-lsp")
+  ensure
+    FileUtils.rm_r(".ruby-lsp") if Dir.exist?(".ruby-lsp")
+  end
+
   def test_creates_custom_bundle
     Object.any_instance.expects(:system).with(bundle_env(".ruby-lsp/Gemfile"), "(bundle check || bundle install) 1>&2")
     Bundler::LockfileParser.any_instance.expects(:dependencies).returns({}).at_least_once
@@ -32,9 +65,26 @@ def test_creates_custom_bundle
     assert_path_exists(".ruby-lsp/Gemfile.lock")
     assert_path_exists(".ruby-lsp/main_lockfile_hash")
     assert_match("ruby-lsp", File.read(".ruby-lsp/Gemfile"))
+    refute_match("ruby-lsp-rails", File.read(".ruby-lsp/Gemfile"))
     assert_match("debug", File.read(".ruby-lsp/Gemfile"))
   ensure
-    FileUtils.rm_r(".ruby-lsp")
+    FileUtils.rm_r(".ruby-lsp") if Dir.exist?(".ruby-lsp")
+  end
+
+  def test_creates_custom_bundle_for_a_rails_app
+    Object.any_instance.expects(:system).with(bundle_env(".ruby-lsp/Gemfile"), "(bundle check || bundle install) 1>&2")
+    Bundler::LockfileParser.any_instance.expects(:dependencies).returns({ "rails" => true }).at_least_once
+    run_script
+
+    assert_path_exists(".ruby-lsp")
+    assert_path_exists(".ruby-lsp/Gemfile")
+    assert_path_exists(".ruby-lsp/Gemfile.lock")
+    assert_path_exists(".ruby-lsp/main_lockfile_hash")
+    assert_match("ruby-lsp", File.read(".ruby-lsp/Gemfile"))
+    assert_match("debug", File.read(".ruby-lsp/Gemfile"))
+    assert_match("ruby-lsp-rails", File.read(".ruby-lsp/Gemfile"))
+  ensure
+    FileUtils.rm_r(".ruby-lsp") if Dir.exist?(".ruby-lsp")
   end
 
   def test_changing_lockfile_causes_custom_bundle_to_be_rebuilt
@@ -422,6 +472,35 @@ def test_ensures_lockfile_remotes_are_relative_to_default_gemfile
     end
   end
 
+  def test_ruby_lsp_rails_is_automatically_included_in_rails_apps
+    Dir.mktmpdir do |dir|
+      Dir.chdir(dir) do
+        File.write(File.join(dir, "Gemfile"), <<~GEMFILE)
+          source "https://rubygems.org"
+          gem "rails"
+        GEMFILE
+
+        capture_subprocess_io do
+          Bundler.with_unbundled_env do
+            # Run bundle install to generate the lockfile
+            system("bundle install")
+          end
+        end
+
+        Object.any_instance.expects(:system).with(
+          bundle_env(".ruby-lsp/Gemfile"),
+          "(bundle check || bundle install) 1>&2",
+        )
+        Bundler.with_unbundled_env do
+          run_script
+        end
+
+        assert_path_exists(".ruby-lsp/Gemfile")
+        assert_match('gem "ruby-lsp-rails"', File.read(".ruby-lsp/Gemfile"))
+      end
+    end
+  end
+
   private
 
   # This method runs the script and then immediately unloads it. This allows us to make assertions against the effects