Incorrect parsing of certain catch syntax

[kbarros]

Consider this code with a non-idiomatic catch statement:

code1 = raw"""
try
    error("Whoops")
catch (e)
    println("Found $e")
end
"""

Julia Formatter moves (e) inside the catch block:

using JuliaFormatter
code2 = format_text(code1)

@assert code2 == raw"""
try
    error("Whoops")
catch
    (e)
    println("Found $e")
end
"""

This transformation changes the meaning of the code:

eval(Meta.parse(code1)) # Found ErrorException("Whoops")
eval(Meta.parse(code2)) # ERROR: UndefVarError: `e` not defined

It seems the correct fix would be to remove the parentheses in catch e.

[domluna]

the issue is with CSTParser

julia> x = CSTParser.parse(code1)
  1:62  try
  1:16   block
  1:16    call
  1:5      error
  6:13     STRING: Whoops
 17:16   FALSE:
 17:44   block
 17:24    brackets
 17:17     e
 25:44    call
 25:31     println
 32:41     string
 32:38      STRING: Found
 39:39      e

julia> x = CSTParser.parse(code2)
  1:60  try
  1:16   block
  1:16    call
  1:5      error
  6:13     STRING: Whoops
 17:22   e
 23:42   block
 23:42    call
 23:29     println
 30:39     string
 30:36      STRING: Found
 37:37      e

julia> Meta.parse(code1)
:(try
      #= none:2 =#
      error("Whoops")
  catch e
      #= none:4 =#
      println("Found $(e)")
  end)

julia> Meta.parse(code2)
:(try
      #= none:2 =#
      error("Whoops")
  catch e
      #= none:4 =#
      println("Found $(e)")
  end)

In the case of (e) it thinks that's the body of the catch block

code1 is the original one with catch (e), code2 is catch e