Dialyzer error on Code.format_string! in 1.19

[angelikatyborska]

Elixir and Erlang/OTP versions

$ elixir --version
Erlang/OTP 28 [erts-16.1] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1] [jit]

Elixir 1.19.3 (compiled with Erlang/OTP 28)

Operating system

macOS 14.7.6 (23H626)

Current behavior

When I run dialyzer via dialyxir (1.4.7), this line of code:

Code.format_string!("", line_length: 120, force_do_end_blocks: true)

produces this error:

The function call will not succeed.

Code.format_string!(<<>>, [{:line_length, 120}, {:force_do_end_blocks, true}])

will never return since the 2nd arguments differ
from the success typing arguments:

(binary(), [
  {:column
   | :columns
   | :emit_warnings
   | :existing_atoms_only
   | :file
   | :indentation
   | :line
   | :literal_encoder
   | :static_atoms_encoder
   | :token_metadata
   | :unescape, boolean() | binary() | (... -> any) | non_neg_integer()}
])

In Elixir 1.18.1, this code did not produce any dialyzer error. AFAIK the API of this function didn't change. I'm using the formatting options that are listed in the docs: https://hexdocs.pm/elixir/Code.html#t:format_opt/0

Expected behavior

No dialyzer errors.

[michallepicki]

👋🏻
Dialyzer concludes that these must be the only "valid" opts because of how they are passed through with ++opts to the string_to_quoted_with_comments! call where these are the only allowed parser_opts. This is similar to what was reported for EEx custom engines here