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Plack::Test::Agent(3) User Contributed Perl Documentation Plack::Test::Agent(3)


Plack::Test::Agent - OO interface for testing low-level Plack/PSGI apps


version 1.5


    use Test::More;
    use Plack::Test::Agent;
    my $app          = sub { ... };
    my $local_agent  = Plack::Test::Agent->new( app => $app );
    my $server_agent = Plack::Test::Agent->new(
                        app    => $app,
                        server => 'HTTP::Server::Simple' );
    my $local_res    = $local_agent->get( '/' );
    my $server_res   = $server_agent->get( '/' );
    ok $local_res->is_success,  'local GET / should succeed';
    ok $server_res->is_success, 'server GET / should succeed';


"Plack::Test::Agent" is an OO interface to test PSGI applications. It can perform GET and POST requests against PSGI applications either in process or over HTTP through a Plack::Handler compatible backend.

NOTE: This is an experimental module and its interface may change.



The "new" constructor creates an instance of "Plack::Test::Agent". This constructor takes one mandatory named argument and several optional arguments.

  • "app" is the mandatory argument. You must provide a PSGI application to test.
  • "server" is an optional argument. When provided, "Plack::Test::Agent" will attempt to start a PSGI handler and will communicate via HTTP to the application running through the handler. See Plack::Loader for details on selecting the appropriate server.
  • "host" is an optional argument representing the name or IP address for the server to use. The default is "localhost".
  • "port" is an optional argument representing the TCP port to for the server to use. If not provided, the service will run on a randomly selected available port outside of the IANA reserved range. (See Test::TCP for details on the selection of the port number.)
  • "ua" is an optional argument of something which conforms to the LWP::UserAgent interface such that it provides a "request" method which takes an HTTP::Request object and returns an HTTP::Response object. The default is an instance of "LWP::UserAgent".
  • "jar" is an optional argument for a HTTP::Cookies instance that will be used as cookie jar for the requests, by default plain one is created.


This class provides several useful methods:


This method takes a URI and makes a "GET" request against the PSGI application with that URI. It returns an HTTP::Response object representing the results of that request.


This method takes a URI and makes a "POST" request against the PSGI application with that URI. It returns an HTTP::Response object representing the results of that request. As an optional second parameter, pass an array reference of key/value pairs for the form content:

    $agent->post( '/edit_user',
            shoe_size => '10.5',
            eye_color => 'blue green',
            status    => 'twin',


This method takes an HTTP::Request, performs it against the bound app, and returns an HTTP::Response. This allows you to craft your own requests directly.


Used internally to create a default UserAgent, if none is provided to the constructor. Returns a Test::WWW::Mechanize::Bound object.


Used internally to ensure that all requests use the correct scheme, host and port. The scheme and host default to "http" and "localhost" respectively, while the port is determined by Test::TCP.


Starts a test server via Test::TCP. If a "server" arg has been provided to the constructor, it will use this class to load a server. Defaults to letting Plack::Loader decide which server class to use.


Thanks to Zbigniew Łukasiak and Tatsuhiko Miyagawa for suggestions.


  • chromatic <>
  • Dave Rolsky <>
  • Ran Eilam <>
  • Olaf Alders <>


  • Dave Rolsky <>
  • Olaf Alders <>
  • Ran Eilam <>
  • Syohei YOSHIDA <>
  • Torsten Raudssus <>


This software is copyright (c) 2011 by chromatic.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

2021-01-22 perl v5.38.2