Introduce .ruby-lsp config file

.ruby-lsp.yml

@@ -0,0 +1,3 @@
+indexing:
+  excluded_patterns:
+    - "**/test/fixtures/**/*.rb"

README.md

@@ -68,6 +68,10 @@ See the [documentation](https://shopify.github.io/ruby-lsp) for more in-depth de
 For creating rich themes for Ruby using the semantic highlighting information, see the [semantic highlighting
 documentation](SEMANTIC_HIGHLIGHTING.md).
 
+## Configuration
+
+Configuration is read from an optional `.ruby-lsp.yml` file in the root of your project.
+
 ### Configuring code indexing
 
 By default, the Ruby LSP indexes all Ruby files defined in the current project and all of its dependencies, including
@@ -76,26 +80,30 @@ default gems, except for
 - Gems that only appear under the `:development` group
 - All Ruby files under `test/**/*.rb`
 
-By creating a `.index.yml` file, these configurations can be overridden and tuned. Note that indexing dependent behavior, such as definition, hover, completion or workspace symbol will be impacted by the configurations placed here.
+Within the `.ruby-lsp.yml` file, these configurations can be overridden and tuned. Note that indexing dependent behavior, such as definition, hover, completion or workspace symbol will be impacted by the configurations placed here.
 
 ```yaml
 # Exclude files based on a given pattern. Often used to exclude test files or fixtures
-excluded_patterns:
-  - "**/spec/**/*.rb"
+indexing:
+  excluded_patterns:
+    - "**/spec/**/*.rb"
 
 # Include files based on a given pattern. Can be used to index Ruby files that use different extensions
-included_patterns:
+indexing:
+  included_patterns:
   - "**/bin/*"
 
 # Exclude gems by name. If a gem is never referenced in the project's code and is only used as a tool, excluding it will
 # speed up indexing and reduce the amount of results in features like definition or completion
-excluded_gems:
-  - rubocop
-  - pathname
+indexing:
+  excluded_gems:
+    - rubocop
+    - pathname
 
 # Include gems by name. Normally used to include development gems that are excluded by default
-included_gems:
-  - prism
+indexing:
+  included_gems:
+    - prism
 ```
 
 ### Addons

lib/ruby_lsp/configuration.rb

@@ -0,0 +1,30 @@
+# typed: strict
+# frozen_string_literal: true
+
+module RubyLsp
+  class Configuration
+    extend T::Sig
+
+    sig { params(workspace_uri: URI::Generic).void }
+    def initialize(workspace_uri)
+      @workspace_uri = workspace_uri
+    end
+
+    sig { returns(T::Hash[String, T.untyped]) }
+    def indexing
+      # Need to use the workspace URI, otherwise, this will fail for people working on a project that is a symlink.
+      index_path = File.join(@workspace_uri.to_standardized_path, ".index.yml")
+      ruby_lsp_path = File.join(@workspace_uri.to_standardized_path, ".ruby-lsp.yml")
+
+      if File.exist?(index_path)
+        $stderr.puts("The .index.yml configuration file is deprecated. Please rename it to .ruby-lsp.yml and update the
+          structure as described in the README: https://github.com/Shopify/ruby-lsp#configuration")
+        YAML.parse_file(index_path).to_ruby
+      elsif File.exist?(ruby_lsp_path)
+        YAML.parse_file(ruby_lsp_path).to_ruby.fetch("indexing")
+      else
+        {}
+      end
+    end
+  end
+end

lib/ruby_lsp/internal.rb

@@ -20,6 +20,7 @@
 require "language_server-protocol"
 
 require "ruby-lsp"
+require "ruby_lsp/configuration"
 require "ruby_lsp/base_server"
 require "ruby_indexer/ruby_indexer"
 require "core_ext/uri"

lib/ruby_lsp/server.rb

@@ -235,27 +235,21 @@ def run_initialized
       end
 
       RubyVM::YJIT.enable if defined?(RubyVM::YJIT.enable)
-
       indexing_config = {}
 
-      # Need to use the workspace URI, otherwise, this will fail for people working on a project that is a symlink.
-      index_path = File.join(@store.workspace_uri.to_standardized_path, ".index.yml")
-
-      if File.exist?(index_path)
-        begin
-          indexing_config = YAML.parse_file(index_path).to_ruby
-        rescue Psych::SyntaxError => e
-          message = "Syntax error while loading configuration: #{e.message}"
-          send_message(
-            Notification.new(
-              method: "window/showMessage",
-              params: Interface::ShowMessageParams.new(
-                type: Constant::MessageType::WARNING,
-                message: message,
-              ),
+      begin
+        indexing_config = Configuration.new(@store.workspace_uri).indexing
+      rescue => e
+        message = "#{e.class} while loading indexing configuration: #{e.message}"
+        send_message(
+          Notification.new(
+            method: "window/showMessage",
+            params: Interface::ShowMessageParams.new(
+              type: Constant::MessageType::WARNING,
+              message: message,
             ),
-          )
-        end
+          ),
+        )
       end
 
       perform_initial_indexing(indexing_config)

test/configuration_test.rb

@@ -0,0 +1,60 @@
+# typed: true
+# frozen_string_literal: true
+
+require "test_helper"
+
+module RubyLsp
+  class ConfigurationTest < Minitest::Test
+    def test_returns_empty_hash_when_no_configuration_files_exist
+      FileUtils.mv(".ruby-lsp.yml", ".ruby-lsp.yml.tmp")
+      workspace_uri = URI::Generic.build(scheme: "file", host: nil, path: "/path/to/workspace")
+
+      result = RubyLsp::Configuration.new(workspace_uri).indexing
+
+      assert_empty(result)
+    ensure
+      FileUtils.mv(".ruby-lsp.yml.tmp", ".ruby-lsp.yml")
+    end
+
+    def test_supports_depecated_index_configuration_file
+      FileUtils.mv(".ruby-lsp.yml", ".ruby-lsp.yml.tmp")
+      File.write(".index.yml", <<~YAML)
+        excluded_patterns:
+        - "**/test/fixtures/**/*.rb"
+      YAML
+      workspace_uri = URI::Generic.build(scheme: "file", host: nil, path: Dir.pwd)
+
+      result = RubyLsp::Configuration.new(workspace_uri).indexing
+
+      assert_equal({ "excluded_patterns" => ["**/test/fixtures/**/*.rb"] }, result)
+    ensure
+      FileUtils.mv(".ruby-lsp.yml.tmp", ".ruby-lsp.yml")
+      FileUtils.rm_f(".index.yml")
+    end
+
+    def test_supports_newer_configuration
+      workspace_uri = URI::Generic.build(scheme: "file", host: nil, path: Dir.pwd)
+
+      result = RubyLsp::Configuration.new(workspace_uri).indexing
+
+      assert_equal({ "excluded_patterns" => ["**/test/fixtures/**/*.rb"] }, result)
+    end
+
+    def test_raises_if_indexing_key_is_missing
+      FileUtils.mv(".ruby-lsp.yml", ".ruby-lsp.yml.tmp")
+      File.write(".ruby-lsp.yml", <<~YAML)
+        excluded_patterns:
+        - "**/test/fixtures/**/*.rb"
+      YAML
+      workspace_uri = URI::Generic.build(scheme: "file", host: nil, path: Dir.pwd)
+
+      error = assert_raises do
+        RubyLsp::Configuration.new(workspace_uri).indexing
+      end
+      assert_equal("key not found: \"indexing\"", error.message)
+      assert_instance_of(KeyError, error)
+    ensure
+      FileUtils.mv(".ruby-lsp.yml.tmp", ".ruby-lsp.yml")
+    end
+  end
+end

test/server_test.rb

@@ -326,18 +326,19 @@ def test_initialize_features_with_enable_all_configuration
   end
 
   def test_handles_invalid_configuration
-    FileUtils.mv(".index.yml", ".index.yml.tmp")
-    File.write(".index.yml", "} invalid yaml")
+    FileUtils.mv(".ruby-lsp.yml", ".ruby-lsp.yml.tmp")
+    File.write(".ruby-lsp.yml", "}")
 
     @server.process_message({ method: "initialized" })
     notification = @server.pop_response
     assert_equal("window/showMessage", notification.method)
     assert_match(
       /Syntax error while loading configuration/,
       T.cast(notification.params, RubyLsp::Interface::ShowMessageParams).message,
+      "Psych::SyntaxError while loading indexing configuration:",
     )
   ensure
-    FileUtils.mv(".index.yml.tmp", ".index.yml")
+    FileUtils.mv(".ruby-lsp.yml.tmp", ".ruby-lsp.yml")
   end
 
   def test_detects_rubocop_if_direct_dependency