Fix keywords and operators being kept when parsing a parent node fails (

#630)

Co-authored-by: Sijawusz Pur Rahnama <sija@sija.pl>

spec/language_server/semantic_tokens/component

@@ -0,0 +1,106 @@
+component Test {
+  property nextTitle : String = "World"
+
+  /*
+  Comment that spans
+  multiple lines
+  */
+  fun title : String {
+    nextTitle
+  }
+
+  fun render {
+    <div/>
+  }
+}
+------------------------------------------------------------------file test.mint
+{
+  "id": 0,
+  "method": "initialize",
+  "params": {
+    "capabilities": {
+      "textDocument": {
+        "semanticTokens": {
+          "dynamicRegistration": false,
+          "tokenTypes": ["property"]
+        }
+      }
+    }
+  }
+}
+-------------------------------------------------------------------------request
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "params": {
+    "textDocument": {
+      "uri": "file://#{root_path}/test.mint"
+    }
+  },
+  "method": "textDocument/semanticTokens/full"
+}
+-------------------------------------------------------------------------request
+{
+  "jsonrpc": "2.0",
+  "result": {
+    "data": [
+      0,
+      0,
+      9,
+      4,
+      0,
+      0,
+      10,
+      4,
+      1,
+      0,
+      1,
+      2,
+      8,
+      4,
+      0,
+      0,
+      21,
+      6,
+      1,
+      0,
+      0,
+      9,
+      7,
+      8,
+      0,
+      2,
+      2,
+      48,
+      5,
+      0,
+      4,
+      2,
+      3,
+      4,
+      0,
+      0,
+      12,
+      6,
+      1,
+      0,
+      1,
+      4,
+      9,
+      6,
+      0,
+      3,
+      2,
+      3,
+      4,
+      0,
+      1,
+      5,
+      3,
+      2,
+      0
+    ]
+  },
+  "id": 1
+}
+------------------------------------------------------------------------response

src/parser.cr

@@ -22,16 +22,29 @@ module Mint
 
     def start(&)
       start_position = position
-      node_size = ast.nodes.size
+
+      nodes_size = ast.nodes.size
+      keywords_size = ast.keywords.size
+      operators_size = ast.operators.size
 
       begin
         node = yield position
         @position = start_position unless node
-        ast.nodes.delete_at(node_size...) unless node
+
+        unless node
+          ast.nodes.delete_at(nodes_size...)
+          ast.keywords.delete_at(keywords_size...)
+          ast.operators.delete_at(operators_size...)
+        end
+
         node
       rescue error : Error
         @position = start_position
-        ast.nodes.delete_at(node_size...)
+
+        ast.nodes.delete_at(nodes_size...)
+        ast.keywords.delete_at(keywords_size...)
+        ast.operators.delete_at(operators_size...)
+
         raise error
       end
     end