How regroup all rescues of begin block and switch type of error later?

Question

for this moment I have a block like

  begin
    yield
  rescue MyError => e
    call_specific_method
    call_method_foo
    render json: { error: e.to_s }
  rescue ActiveRecord::RecordInvalid => e
    call_specific_method
    call_method_foo
    render json: { error: e.to_s }
  rescue => e
    call_specific_method
    call_method_foo
    render json: { error: e.to_s }
  end

so I have lot of duplicate instructions because they are similar for each exception :

call_method_foo
render json: { error: e.to_s }

but I have specific instructions too :

call_specific_method

I need to do something like :

  begin
    yield
  rescue => e
    if e.type == ActiveRecord::RecordInvalid
       call_specific_method
    elsif e.type == MyError
       call_specific_method
    else
      call_specific_method
    end
    call_method_foo
    render json: { error: e.to_s }
  end

So how can I test type of exception in single rescue ?

score 1 · Accepted Answer · answered Feb 19 '15 at 14:15

1

You can test the exception class like this:

rescue => e
  if e.is_a?(ActiveRecord::RecordInvalid)
    ...
  end
end

In any case, I'd better extract the common code to an external private method:

def foo
  ...
  begin
    yield
  rescue MyError => e
    call_specific_method
    render_error_for(e)
  rescue ActiveRecord::RecordInvalid => e
    call_specific_method
    render_error_for(e)
  rescue => e
    call_specific_method
    render_error_for(e)
  end
end

def render_error_for(e)
  call_method_foo
  render json: { error: e.to_s }
end

answered Feb 19 '15 at 14:15

dgilperez

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why it's better extract common code and not specific code? – Matrix Feb 19 '15 at 14:19
I assumed that every ``call_specific_method`` is different for every exception class, isn't it? – dgilperez Feb 19 '15 at 14:29
yes, ok, in fact the rescue list, is same like my if, so it's ok, thx. – Matrix Feb 19 '15 at 14:52
I just test, but only one rescue `rescue => e`, don't catch all exceptions errors... – Matrix Feb 19 '15 at 15:01
Which one is not catching? Which code are you using? – dgilperez Feb 19 '15 at 15:03
I found, for catch all in one rescue, just use top of Exception hierarchy with : `rescue Exception => e` instead of `rescue => e` – Matrix Feb 19 '15 at 15:06

How regroup all rescues of begin block and switch type of error later?

1 Answers1