+ builder.rb: disallow kwargs and blocks in indexasgn for Ruby 3.4

lib/parser/builders/default.rb

@@ -1192,6 +1192,19 @@ def index(receiver, lbrack_t, indexes, rbrack_t)
     end
 
     def index_asgn(receiver, lbrack_t, indexes, rbrack_t)
+      if @parser.version >= 34 && (last = indexes.last)
+        if kwargs?(last)
+          diagnostic :error, :invalid_arg_in_index_assign, { :type => "keyword"}, last.loc.expression
+        end
+        if last.type == :block_pass
+          diagnostic :error, :invalid_arg_in_index_assign, { :type => "block"}, last.loc.expression
+        end
+      end
+
+      if self.class.emit_kwargs
+        rewrite_hash_args_to_kwargs(indexes)
+      end
+
       if self.class.emit_index
         n(:indexasgn, [ receiver, *indexes ],
           index_map(receiver, lbrack_t, rbrack_t))

lib/parser/messages.rb

@@ -85,6 +85,7 @@ module Parser
     :ambiguous_anonymous_restarg   => 'anonymous rest parameter is also used within block',
     :ambiguous_anonymous_kwrestarg => 'anonymous keyword rest parameter is also used within block',
     :ambiguous_anonymous_blockarg  => 'anonymous block parameter is also used within block',
+    :invalid_arg_in_index_assign   => '%{type} argument given in index assignment',
 
     # Parser warnings
     :useless_else            => 'else without rescue is useless',

test/test_parser.rb

@@ -3625,6 +3625,73 @@ def test_send_index_asgn_legacy
     Parser::Builders::Default.emit_index = true
   end
 
+  def test_send_index_asgn_kwarg
+    assert_parses(
+      s(:indexasgn,
+        s(:lvar, :foo),
+        s(:kwargs,
+          s(:pair,
+            s(:sym, :kw),
+            s(:send, nil, :arg))),
+        s(:int, 3)),
+      %q{foo[:kw => arg] = 3},
+      %q{},
+      ALL_VERSIONS - SINCE_3_4)
+  end
+
+  def test_send_index_asgn_kwarg_legacy
+    Parser::Builders::Default.emit_kwargs = false
+    assert_parses(
+      s(:indexasgn,
+        s(:lvar, :foo),
+        s(:hash,
+          s(:pair,
+            s(:sym, :kw),
+            s(:send, nil, :arg))),
+        s(:int, 3)),
+      %q{foo[:kw => arg] = 3},
+      %q{},
+      ALL_VERSIONS - SINCE_3_4)
+  ensure
+    Parser::Builders::Default.emit_kwargs = true
+  end
+
+  def test_send_index_asgn_since_34
+    [true, false].each do |emit_kwargs|
+      Parser::Builders::Default.emit_kwargs = emit_kwargs
+
+      [
+        %q{foo[:kw => arg] = 3},
+        %q{foo[**args] = 3},
+        %q{def x(**); foo[**] = 3; end},
+      ].each do |code|
+        assert_diagnoses(
+          [:error, :invalid_arg_in_index_assign, { :type => "keyword" }],
+          code,
+          %q{},
+          SINCE_3_4)
+      end
+
+      refute_diagnoses(
+        %q{foo[{}]},
+        ALL_VERSIONS)
+
+      [
+        %q{foo[&blk] = 3},
+        %q{def x(&); foo[&] = 3; end},
+        %q{foo[&method(:foo)] = 3},
+      ].each do |code|
+        assert_diagnoses(
+          [:error, :invalid_arg_in_index_assign, { :type => "block" }],
+          code,
+          %q{},
+          SINCE_3_4)
+      end
+    ensure
+      Parser::Builders::Default.emit_kwargs = true
+    end
+  end
+
   def test_send_lambda
     assert_parses(
       s(:block, s(:lambda),