Module file name mismatch compiler error not exposed

[eproxus]

Describe the bug
A module with a name not matching the file name does issue an error.

To Reproduce
Create a module in the file foo.erl:

-module(bar).

Expected behavior
An error similar to the Erlang compilation error should be issued:

$ erlc foo.erl
/path/to/foo.beam: Module name 'bar' does not match file name 'foo'

Actual behavior
No error is visible.

Context

• erlang_ls version (tag/sha): 0.21.1
• Editor used: Sublime Text 4 (4122)
• LSP client used: Sublime LSP v1.14.0

[robertoaloi]

Interesting, thanks for the report. I never noticed this since Emacs' Erlang mode already prevents that.
The fact that the error is not visible is due to the basic_validation parameter which is passed to compile:file/2. Even the strong_validation doesn't seem to help.

[robertoaloi]

Confirmed from the code in OTP. The error is only emitted if a binary is saved, which doesn't happen in the case of basic_validation or strong_validation. I guess we can replicate the check from Erlang LS side.

[eproxus]

Should this be a "bug" report to OTP, in that the compiler doesn't validate this? I assume it's hard coded somewhere else in the Erlang compiler stack then, because erlc generates the error...

I guess it's not strictly seen as an error, because you can produce beam files with whatever -module(Name) attribute you want, and they only fail when you actually load them?