test(logger): add first tests to the centreon::common::logger class

these test use test2::V0, but are not set up in the CI for now, this lib is not packaged for debian.

Refs:MON-106121

connectors/centreonPerlLibs/t/logger.t

@@ -0,0 +1,60 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+use Test2::V0;
+use FindBin;
+use lib "$FindBin::Bin/../src";
+use centreon::common::logger;
+
+# Each function test a different aspect of the library (roughtly one public function each).
+# To be sure there is no side effect each test create it's own test object
+sub test_severity {
+    my $logger = centreon::common::logger->new();
+    is($logger->severity(), "warning", "default severity should be warning.");
+
+    for my $sev ('fatal', 'error', 'warning', 'notice', 'info', 'debug') {
+        $logger->severity($sev);
+        is($logger->severity(), $sev, "severity $sev was correctly set.");
+    }
+}
+# By default the logger should write to stdout, so we capture stdout to a variable and check what the object have written.
+sub test_writeLogInfo {
+    my $logger = centreon::common::logger->new();
+    $logger->flush_output(enabled => 1);
+    $logger->severity("debug");
+    my $out;
+    my $logExemple = "this is an info log.";
+    do {
+        local *STDOUT;
+        open STDOUT, ">", \$out;
+        $logger->writeLogInfo($logExemple);
+    };
+    my $log = check_log_format_with_date_no_pid($out, "info");
+
+    is($log, $logExemple, "log is the same as what we sent.");
+
+    print "written to original STDOUT : $out\n";
+}
+
+sub main {
+    test_severity();
+    test_writeLogInfo();
+    #test_file_mode();
+    #test_is_file_mode();
+
+
+    done_testing;
+}
+# Helper function
+sub check_log_format_with_date_no_pid {
+    # the best way to check the date would be to mock the time() function, and to run get_date().
+    # as it is a builtin function, it is possible but hard to setup and prone various side effect.
+    my $log = shift;
+    my $severity = shift;
+    ok(($log =~ /^\[\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\] \[$severity\] (.*$)/), "log format is respected.");
+    ok((defined $1), "the log is not empty");
+    return $1;
+}
+
+&main;