Array#fill double error?

[djberg96]

Not sure what's happening here, but it seems to raise two errors, an ArgumentError and a TypeError. It should just be a TypeError:

TruffleRuby 22.1.0:

> a = %w[a b c d]
=> ["a", "b", "c", "d"]
irb(main):002:0> a.fill('x', 1, 'x')
<internal:core> core/array.rb:461:in `fill_internal': second argument must be an Integer (ArgumentError)
	from (irb):2:in `fill'
	from (irb):2:in `<top (required)>'
	from <internal:core> core/kernel.rb:407:in `loop'
	from <internal:core> core/throw_catch.rb:36:in `catch'
	from <internal:core> core/throw_catch.rb:36:in `catch'
	from /home/dberger/.rbenv/versions/truffleruby-22.1.0/lib/gems/gems/irb-1.3.5/exe/irb:11:in `<top (required)>'
	from <internal:core> core/kernel.rb:376:in `load'
	from <internal:core> core/kernel.rb:376:in `load'
	from /home/dberger/.rbenv/versions/truffleruby-22.1.0/bin/irb:42:in `<main>'
<internal:core> core/type.rb:276:in `convert_type': no implicit conversion of String into Integer (TypeError)
	from <internal:core> core/type.rb:178:in `rb_to_int_fallback'
	from <internal:core> core/array.rb:459:in `fill_internal'
	from (irb):2:in `fill'
	from (irb):2:in `<top (required)>'
	from <internal:core> core/kernel.rb:407:in `loop'
	from <internal:core> core/throw_catch.rb:36:in `catch'
	from <internal:core> core/throw_catch.rb:36:in `catch'
	from /home/dberger/.rbenv/versions/truffleruby-22.1.0/lib/gems/gems/irb-1.3.5/exe/irb:11:in `<top (required)>'
	from <internal:core> core/kernel.rb:376:in `load'
	from <internal:core> core/kernel.rb:376:in `load'
	from /home/dberger/.rbenv/versions/truffleruby-22.1.0/bin/irb:42:in `<main>'

Ruby 3.0.x:

> a = %w[a b c d]
=> ["a", "b", "c", "d"]
irb(main):002:0> a.fill('x', 1, 'x')
(irb):2:in `fill': no implicit conversion of String into Integer (TypeError)
	from (irb):2:in `<main>'
	from /home/dberger/.rbenv/versions/3.0.4/lib/ruby/gems/3.0.0/gems/irb-1.3.5/exe/irb:11:in `<top (required)>'
	from /home/dberger/.rbenv/versions/3.0.4/bin/irb:23:in `load'
	from /home/dberger/.rbenv/versions/3.0.4/bin/irb:23:in `<main>'

[eregon]

It's best to reproduce this outside of IRB for simplicity and smaller stacktraces:

$ ruby -e '%w[a b c d].fill("x", 1, "x")'
-e:1:in `fill': no implicit conversion of String into Integer (TypeError)
	from -e:1:in `<main>'


$ truffleruby -e '%w[a b c d].fill("x", 1, "x")'
<internal:core> core/array.rb:461:in `fill_internal': second argument must be an Integer (ArgumentError)
	from -e:1:in `fill'
	from -e:1:in `<main>'
<internal:core> core/type.rb:276:in `convert_type': no implicit conversion of String into Integer (TypeError)
	from <internal:core> core/type.rb:178:in `rb_to_int_fallback'
	from <internal:core> core/array.rb:459:in `fill_internal'
	from -e:1:in `fill'
	from -e:1:in `<main>'

It's simply an exception which has a cause.
Which is not surprising given the code is this:

truffleruby/src/main/ruby/truffleruby/core/array.rb

Lines 458 to 462 in 50a95cf

	begin
	right = Primitive.rb_num2int length
	rescue TypeError
	raise ArgumentError, 'second argument must be an Integer'
	end

So I guess we should change that to be a TypeError and not ArgumentError, but otherwise I think we should leave the cause as it is to reflect the wrapped and the original exception.

BTW the error message from CRuby is very confusing, 'x' is what fails to be converted and that's the 3rd argument not the 2nd. Maybe we should not try to match CRuby's message since it's not that helpful, and just let the original TypeError propagate, then we would also not need another exception.

[djberg96]

BTW the error message from CRuby is very confusing, 'x' is what fails to be converted and that's the 3rd argument not the 2nd.

I'm not following. The CRuby error message looks correct to me. It's only the Truffleruby error message that makes reference to the 2nd argument.

[eregon]

Oh you are right, I confused the output somehow.
Then we we just remove this rescue TypeError + raise ArgumentError (which I guess comes from Rubinius) and we should match CRuby.

[andrykonchin]

Fixed in 4693f7b, thank you for the report.