Mojo::Pg: "Wide character in subroutine entry" on UPDATE with UTF-8 data

[daboe01]

Hello everyone,

I'm encountering a Wide character in subroutine entry exception when trying to update a PostgreSQL table using Mojo::Pg. The error seems to be triggered when the JSON payload for the update contains non-ASCII characters.

Environment

• Perl: v5.42.0
• Mojolicious: 9.41
• Mojo::Pg: 4.27

The Code

I have a generic PUT route that takes a table name, primary key, and JSON data to perform an update. Here is a simplified version of the route handler:

# In my Mojolicious::Lite app
helper pg => sub { state $pg = Mojo::Pg->new('postgresql://docker:docker@localhost/my_database') };



put '/LLM/:table/:pk/:key' => [key => qr/\d+/] => sub {
    my $self = shift;
    
    my $table  = $self->param('table');
    my $pk_col = $self->param('pk');
    my $pk_val = $self->param('key');
    my $data   = $self->req->json;

    # The following call triggers the exception
    eval {
        $self->pg->db->update($table, $data, {$pk_col => $pk_val});
    };

    if (my $err = $@) {
        $self->app->log->error("Database update failed: $err");
        return $self->render(
            json   => {error => "Update failed: $err"},
            status => 500
        );
    }

    $self->render(json => {success => 1});
};

How to Reproduce

The issue occurs when I send a PUT request with a JSON payload containing wide characters. Specifically, the following content value, which ends with an "en dash" (–, U+2013), causes the error.

Payload that causes the error:

{
  "content": "TITLE\n–"
}

The Exception

When the route is hit with the payload above, I get this exact error:

Wide character in subroutine entry at /usr/local/lib/perl5/site_perl/5.42.0/Mojo/Pg/Database.pm line 98.

My Analysis

It appears that Mojo::JSON correctly decodes the incoming request into a Perl string with the UTF-8 flag enabled. However, when this data is passed to Mojo::Pg's update method, it seems to trigger this low-level warning which is escalated to an exception by eval. If I remove the trailing – character, the update succeeds without any issues.

My Question

What is the correct way to handle UTF-8 data for database updates with Mojo::Pg? Am I missing a configuration step, either in my database connection string or in the application itself, to ensure all character data is properly encoded before being passed to the database?

Thanks in advance for any help or guidance

[daboe01]

sorry for the confusion. it turned out that my postgres database was not initialized on UTF8.
nothing wrong with mojo :-)