[lukaszsamson]

Problem

Completion and signature help crash when a module's .beam is malformed or truncated (e.g. while being rewritten by a concurrent compile):

an exception was raised:
  ...]}}
    (stdlib 6.2.2) beam_lib.erl:712: :beam_lib.read_info/1
    (elixir 1.18.2) code/typespec.ex:173: Code.Typespec.get_module_and_beam/1
    (elixir 1.18.2) code/typespec.ex:152: Code.Typespec.typespecs_abstract_code/1
    (elixir 1.18.2) code/typespec.ex:121: Code.Typespec.fetch_specs/1
    elixir_sense/core/normalized/typespec.ex:9: ElixirSense.Core.Normalized.Typespec.get_specs/1
    elixir_sense/core/type_info.ex:379: ElixirSense.Core.TypeInfo.get_module_specs/1

:beam_lib.read_info/1 only catches throws, so error/exit exceptions from parsing corrupt chunks escape Code.Typespec.fetch_*.

Fix

ElixirSense.Core.Normalized.Typespec.get_specs/1, get_types/1 and get_callbacks/1 now wrap the Code.Typespec.fetch_* call so any raise/exit/throw is treated as :error, which yields [].

Only callers of Code.Typespec in lib/ go through this module. ExckReader (which uses :beam_lib directly) has no callers in lib/, so it is unchanged.

Test

Added a test that writes a .beam with one byte flipped at offset 25 (inside the atom chunk) to a temp dir on the code path. Without the fix it raises MatchError from :beam_lib; with the fix all three functions return [].