Use a needs_parsing boolean instead of unparsed edits array (#1032)

lib/ruby_lsp/document.rb

@@ -28,7 +28,7 @@ def initialize(source:, version:, uri:, encoding: Constant::PositionEncodingKind
       @source = T.let(source, String)
       @version = T.let(version, Integer)
       @uri = T.let(uri, URI::Generic)
-      @unparsed_edits = T.let([], T::Array[EditShape])
+      @needs_parsing = T.let(false, T::Boolean)
       @parse_result = T.let(YARP.parse(@source), YARP::ParseResult)
     end
 
@@ -87,15 +87,15 @@ def push_edits(edits, version:)
       end
 
       @version = version
-      @unparsed_edits.concat(edits)
+      @needs_parsing = true
       @cache.clear
     end
 
     sig { void }
     def parse
-      return if @unparsed_edits.empty?
+      return unless @needs_parsing
 
-      @unparsed_edits.clear
+      @needs_parsing = false
       @parse_result = YARP.parse(@source)
     end
 

test/document_test.rb

@@ -502,13 +502,26 @@ def baz
   def test_reparsing_without_new_edits_does_nothing
     document = RubyLsp::Document.new(source: +"", version: 1, uri: URI("file:///foo/bar.rb"))
     document.push_edits(
-      [{ range: { start: { line: 0, character: 0 }, end: { line: 0, character: 0 } }, text: "def foo" }],
+      [{ range: { start: { line: 0, character: 0 }, end: { line: 0, character: 0 } }, text: "def foo; end" }],
       version: 2,
     )
 
+    # When there's a new edit, we parse it the first `parse` invocation
+    YARP.expects(:parse).with(document.source).once
+    document.parse
+
+    # If there are no new edits, we don't do anything
+    YARP.expects(:parse).never
+    document.parse
+
+    document.push_edits(
+      [{ range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } }, text: "\ndef bar; end" }],
+      version: 3,
+    )
+
+    # If there's another edit, we parse it once again
+    YARP.expects(:parse).with(document.source).once
     document.parse
-    assert_predicate(document, :syntax_error?)
-    assert_empty(document.instance_variable_get(:@unparsed_edits))
   end
 
   def test_cache_set_and_get