Add test covering dewebsockify modulino

Related Issue: https://progress.opensuse.org/issues/174232

t/39-dewebsockify.t

@@ -0,0 +1,98 @@
+#!/usr/bin/perl
+#
+# Copyright 2019-2024 SUSE LLC
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+use Test::Most;
+use Mojo::Base;
+use Test::MockModule;
+use Test::Warnings;
+use Mojo::Log;
+use Mojo::IOLoop::Server;
+
+BEGIN {
+    require OpenQA::Isotovideo::Dewebsockify;
+}
+
+my $accept_callback;
+
+my $mock_server = Test::MockModule->new('Mojo::IOLoop::Server');
+$mock_server->mock(
+    new => sub {
+        return bless {}, 'Mojo::IOLoop::Server';
+    },
+    on => sub {
+        my ($self, $event, $cb) = @_;
+        if ($event eq 'accept') {
+            # saving callback for reusing later
+            $accept_callback = $cb;
+        }
+    },
+    listen => sub { },
+    start => sub { },
+);
+
+my $mock_stream = Test::MockModule->new('Mojo::IOLoop::Stream');
+$mock_stream->mock(new => sub { return bless {}, 'Mojo::IOLoop::Stream'; });
+$mock_stream->mock(start => sub { });
+$mock_stream->mock(on => sub { });
+$mock_stream->mock(close_gracefully => sub { });
+
+my $mock_ua = Test::MockModule->new('Mojo::UserAgent');
+$mock_ua->mock(new => sub { bless {}, 'Mojo::UserAgent' });
+
+$mock_ua->mock(build_websocket_tx => sub {
+        my ($self, $url) = @_;
+        return bless {}, 'MockTx';
+});
+
+$mock_ua->mock(start => sub {
+        my ($self, $tx, $cb) = @_;
+        $cb->($self, $tx);
+});
+
+# simulating failed handshake
+{
+    package MockTx;
+    sub is_websocket { 0 }
+    sub error { return undef }
+    sub req { return bless {}, 'MockReq'; }
+    sub res { return bless {}, 'MockRes'; }
+
+    package MockReq;
+    sub cookies { }
+    sub headers { return bless {}, 'MockHeaders'; }
+
+    package MockHeaders;
+    sub add { }
+
+    package MockRes;
+    sub body { return 'dummy body'; }
+}
+
+my @log_messages;
+my $mock_log = Test::MockModule->new('Mojo::Log');
+$mock_log->mock(info => sub { push @log_messages, $_[1] });
+$mock_log->mock(error => sub { push @log_messages, $_[1] });
+
+my $args = {
+    websocketurl => 'ws://example.com',
+    listenport => 5900,
+    cookie => undef,
+    loglevel => 'info',
+};
+
+OpenQA::Isotovideo::Dewebsockify::main($args);
+
+$accept_callback->(undef, 'dummy_socket_1');
+
+ok(grep(/Unable to upgrade to WebSocket connection/, @log_messages),
+    'WebSocket upgrade failed without HTTP code as expected.');
+
+like($log_messages[-1], qr/Client accepted/i, 'first client accepted.');
+
+$accept_callback->(undef, 'dummy_socket_2');
+like($log_messages[-1], qr/Rejecting new client/i, 'second client rejected as expected.');
+
+done_testing();
+