nccgroup/sobelow

error handler block in parse.ex throws on syntax error

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#105 opened on Feb 8, 2022

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 (7 comments) (0 reactions) (0 assignees)Elixir (1,780 stars) (119 forks)batch import
backlogbuggood first issue

Description

The following error handling block in lib/sobelow/parse.ex is incorrectly destructuring the line parameter: https://github.com/nccgroup/sobelow/blob/master/lib/sobelow/parse.ex#L45_L51

When scanning my code which contained a syntax error, the line variable was a list instead of a number, looking like this:

[line: 123, column: 456]

This in turn causes the IO.puts line to throw as it can't convert a list to a string.

I fixed this locally by changing the error handling block to the following:

{:error, {line, err, _}} ->
  if Application.get_env(:sobelow, :strict) do
    if is_list(line) do
      IO.puts(:stderr, "#{filepath}:#{line[:line]}:#{line[:column]}}: #{err}")
    else
      IO.puts(:stderr, "#{filepath}:#{line}: #{err}")
    end
    System.halt(2)
  else
    {}
  end

Happy to submit a PR with any feedback you may have.

Contributor guide

Tech stack
None
Domain
security
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
basic Elixir pattern matching
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65
Research direction
Review the proposed fix in lib/sobelow/parse.ex lines 45-51. The error handler block incorrectly destructures the line parameter. Confirm the fix handles both list and integer cases. Consider adding a test for syntax errors. Engage with the user who offered to submit a PR.