Bug #20055: Ripper seems to skip some checks like `void value expression` and `duplicated variable name`

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.0dev (2023-12-08T07:01:01Z master f2c84c4884) [x86_64-linux]
• Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN

[tompng (tomoya ishida)]

These are syntax error

return + return # void value expression
1 in [a, a] # duplicated variable name
1 + (1 => [a, a]) # both

But Ripper.sexp returns S-expression, not nil

Ripper.sexp 'return + return'
# =>
[:program, [[:return, [:args_add_block, [[:unary, :+@, [:return0]]], false]]]]

Ripper.sexp '1 in [a, a]'
# =>
[:program, [[:case, [:@int, "1", [1, 0]], [:in, [:aryptn, nil, [[:var_field, [:@ident, "a", [1, 6]]], [:var_field, [:@ident, "a", [1, 9]]]], nil, nil], nil, nil]]]]

Ripper.sexp '1 + (1 => [a, a]) # both'
# =>
[:program, [[:binary, [:@int, "1", [1, 0]], :+, [:paren, [[:case, [:@int, "1", [1, 5]], [:in, [:aryptn, nil, [[:var_field, [:@ident, "a", [1, 11]]], [:var_field, [:@ident, "a", [1, 14]]]], nil, nil], nil, nil]]]]]]]

[nobu (Nobuyoshi Nakada)]

• Related to Bug #16008: Ripper hshptn node drops information added

[yui-knk (Kaneko Yuichiro)]

• Status changed from Open to Closed

This is solved by https://bugs.ruby-lang.org/issues/20257 (https://github.com/ruby/ruby/pull/9923).