Add support for folding defs

Co-authored-by: Vinicius Stock <vinistock@users.noreply.github.com>

lib/ruby/lsp.rb

@@ -1,3 +1,4 @@
 # frozen_string_literal: true
 
 require_relative "./lsp/cli"
+require "syntax_tree"

lib/ruby/lsp/cli.rb

@@ -11,8 +11,42 @@ def self.start(_argv)
         handler = Ruby::Lsp::Handler.new
 
         handler.config do
-          on("initialize") { respond_with_capabilities }
-          on("shutdown") { shutdown }
+          on("initialize") do
+            store.clear
+            respond_with_capabilities
+          end
+
+          on("textDocument/didChange") do |request|
+            uri = request.dig(:params, :textDocument, :uri)
+            text = request.dig(:params, :contentChanges, 0, :text)
+            store[uri] = text
+
+            nil
+          end
+
+          on("textDocument/didOpen") do |request|
+            uri = request.dig(:params, :textDocument, :uri)
+            text = request.dig(:params, :textDocument, :text)
+            store[uri] = text
+
+            nil
+          end
+
+          on("textDocument/didClose") do |request|
+            uri = request.dig(:params, :textDocument, :uri)
+            store.delete(uri)
+
+            nil
+          end
+
+          on("textDocument/foldingRange") do |request|
+            respond_with_folding_ranges(request.dig(:params, :textDocument, :uri))
+          end
+
+          on("shutdown") do
+            store.clear
+            shutdown
+          end
         end
 
         handler.start

lib/ruby/lsp/handler.rb

@@ -1,8 +1,14 @@
 # frozen_string_literal: true
 
+require "cgi"
+require "uri"
+require_relative "./requests/folding/ranges"
+
 module Ruby
   module Lsp
     class Handler
+      attr_reader :store
+
       Interface = LanguageServer::Protocol::Interface
       Constant = LanguageServer::Protocol::Constant
       Transport = LanguageServer::Protocol::Transport
@@ -12,12 +18,16 @@ def initialize
         @reader = Transport::Stdio::Reader.new
         @handlers = {}
         @running = true
+        @store = Hash.new do |hash, uri|
+          hash[uri] = File.binread(CGI.unescape(URI.parse(uri).path))
+        end
       end
 
       def start
         $stderr.puts "Starting Ruby LSP..."
         @reader.read do |request|
           break unless @running
+
           handle(request)
         end
       end
@@ -52,10 +62,17 @@ def respond_with_capabilities
               resolve_provider: true,
               trigger_characters: ["."]
             ),
+            folding_range_provider: Interface::FoldingRangeClientCapabilities.new(
+              line_folding_only: true
+            ),
             definition_provider: true
           )
         )
       end
+
+      def respond_with_folding_ranges(uri)
+        Ruby::Lsp::Requests::Folding::Ranges.run(store[uri])
+      end
     end
   end
 end

test/requests/folding_ranges_test.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class FoldingRangesTest < Minitest::Test
+  def test_folding_ranges
+    ranges = [{ startLine: 0, endLine: 3, kind: "region" }]
+    assert_ranges(<<~RUBY, ranges)
+      def foo
+        a = 2
+        puts "a"
+      end
+    RUBY
+  end
+
+  private
+
+  def assert_ranges(source, expected_ranges)
+    actual = Ruby::Lsp::Requests::Folding::Ranges.run(source)
+    assert_equal(expected_ranges, JSON.parse(actual.to_json, symbolize_names: true))
+  end
+end