Bug 27806

Summary: Exceptions thrown during a call to ->render are not caught and passed to ->unhandled_exception
Product: Koha Reporter: Martin Renvoize <martin.renvoize>
Component: REST APIAssignee: Bugs List <koha-bugs>
Status: NEW --- QA Contact:
Severity: enhancement    
Priority: P5 - low CC: julian.maurice, tomascohen
Version: master   
Hardware: All   
OS: All   
Change sponsored?: --- Patch complexity: ---
Documentation contact: Documentation submission:
Text to go in the release notes:
Version(s) released in:
Bug Depends on: 27680    
Bug Blocks:    
Attachments: Bug 27806: (follow-up) Add Koha::Exception for bad queries
Bug 27806: (follow-up) Attempt to catch the exception

Description Martin Renvoize 2021-02-26 13:27:50 UTC
Whilst working on 27680 I discovered that we do not catch exceptions that are thrown at the point of render.

I failed to resolve the problem there so have moved this piece to it's own bug.

The tests added catch the 500 responses and those responses are the HTML rendered Mojo::Exception templates..

I'll attach the patches I came up with that are not working as expected :(.

I've also tried using

$self->helper( 'reply.exception' => sub { my ($page, $c, $e) = @_; # Custom error page handling here } );

and

$self->before_render => sub {

  my ($c, $args) = @_;

  # Make sure we are rendering the exception template
  return unless my $template = $args->{template};
  return unless $template eq 'exception';

  # Switch to JSON rendering if content negotiation allows it
  return unless $c->accepts('json');
  $args->{json} = {exception => $c->stash('exception')};
};

and neither appeared to work :(
Comment 1 Martin Renvoize 2021-02-26 13:29:10 UTC
Created attachment 117376 [details] [review]
Bug 27806: (follow-up) Add Koha::Exception for bad queries

This patch adds a PropertyNotFound exception tothe 'as_list' method to
catch DBIx::Class excpetions caused by passing bad column names into a
query.
Comment 2 Martin Renvoize 2021-02-26 13:29:13 UTC
Created attachment 117377 [details] [review]
Bug 27806: (follow-up) Attempt to catch the exception

Help: I'm struggling to catch the point at which the exception should be
thrown to convert it to a 400 error response in the API. '->search' does
not actually trigger the DB hit until we reference some data from it..
so we can't use that.. so I tried '->count', but of course.. that drops
'order_by' which is the failure in this case and so we pass through.