diff --git a/.perlcriticrc b/.perlcriticrc
index 61ab588..a25c6d3 100644
--- a/.perlcriticrc
+++ b/.perlcriticrc
@@ -1,4 +1,5 @@
-severity = 3
+severity = 1
 
 [-TestingAndDebugging::RequireUseStrict]
-[-TestingAndDebugging::RequireUseWarnings]
\ No newline at end of file
+[-TestingAndDebugging::RequireUseWarnings]
+[-CodeLayout::RequireTidyCode]
\ No newline at end of file
diff --git a/.perltidyrc b/.perltidyrc
index f8a793c..6817d69 100644
--- a/.perltidyrc
+++ b/.perltidyrc
@@ -3,4 +3,8 @@
 --continuation-indentation=4
 --square-bracket-tightness=2
 --tight-secret-operators
---maximum-consecutive-blank-lines=1
\ No newline at end of file
+--maximum-consecutive-blank-lines=1
+--nocuddled-else
+--nooutdent-long-quotes
+
+# perltidy -nst -b filename.pl
\ No newline at end of file
diff --git a/cpanfile b/cpanfile
index 1cad3e8..8d2e1a5 100644
--- a/cpanfile
+++ b/cpanfile
@@ -2,4 +2,5 @@ requires "JSON";
 requires "File::Find::Rule", "0.34";
 requires "Getopt::Long", "2.54";
 requires "YAML::Tiny", "1.73";
-requires "PPI::Document";
\ No newline at end of file
+requires "PPI::Document";
+requires "List::Util";
\ No newline at end of file
diff --git a/lib/Zarn/Engine/AST.pm b/lib/Zarn/Engine/AST.pm
index 8e04e5f..75b3a06 100644
--- a/lib/Zarn/Engine/AST.pm
+++ b/lib/Zarn/Engine/AST.pm
@@ -4,7 +4,7 @@ package Zarn::Engine::AST {
     use PPI::Find;
     use Getopt::Long;
     use PPI::Document;
-    
+
     our $VERSION = '0.0.6';
 
     sub new {
@@ -13,14 +13,14 @@ package Zarn::Engine::AST {
 
         Getopt::Long::GetOptionsFromArray (
             $parameters,
-            "file=s"  => \$file
+            'file=s'  => \$file
         );
 
         if ($file) {
             my $document = PPI::Document -> new($file);
 
-            $document -> prune("PPI::Token::Pod");
-            $document -> prune("PPI::Token::Comment");
+            $document -> prune('PPI::Token::Pod');
+            $document -> prune('PPI::Token::Comment');
 
             return $document;
         }
diff --git a/lib/Zarn/Engine/Source_to_Sink.pm b/lib/Zarn/Engine/Source_to_Sink.pm
index cbdde68..c4d07c9 100644
--- a/lib/Zarn/Engine/Source_to_Sink.pm
+++ b/lib/Zarn/Engine/Source_to_Sink.pm
@@ -3,6 +3,7 @@ package Zarn::Engine::Source_to_Sink {
     use warnings;
     use PPI::Find;
     use Getopt::Long;
+    use List::Util 'any';
     use PPI::Document;
     use Zarn::Engine::Taint_Analysis;
 
@@ -14,26 +15,26 @@ package Zarn::Engine::Source_to_Sink {
 
         Getopt::Long::GetOptionsFromArray (
             $parameters,
-            "ast=s"   => \$ast,
-            "rules=s" => \$rules
+            'ast=s'   => \$ast,
+            'rules=s' => \$rules
         );
 
         if ($ast && $rules) {
-            foreach my $token (@{$ast -> find("PPI::Token")}) {
+            foreach my $token (@{$ast -> find('PPI::Token')}) {
                 foreach my $rule (@{$rules}) {
                     my @sample   = $rule -> {sample} -> @*;
                     my $category = $rule -> {category};
                     my $title    = $rule -> {name};
                     my $message  = $rule -> {message};
 
-                    if (grep {my $content = $_; scalar(grep {$content =~ m/$_/xms} @sample)} $token -> content()) {
+                    if (any { my $content = $_; scalar(any { $content =~ m/$_/xms } @sample) } $token -> content()) {
                         my $next_element = $token -> snext_sibling;
 
                         # this is a draft source-to-sink function
                         if (defined $next_element && ref $next_element && $next_element -> content() =~ /[\$\@\%](\w+)/xms) {
                             my $taint_analysis = Zarn::Engine::Taint_Analysis -> new ([
-                                "--ast" => $ast,
-                                "--token" => $1,
+                                '--ast' => $ast,
+                                '--token' => $1,
                             ]);
 
                             if ($taint_analysis) {
@@ -57,7 +58,7 @@ package Zarn::Engine::Source_to_Sink {
 
             return @results;
         }
-        
+
         return 0;
     }
 }
diff --git a/lib/Zarn/Engine/Taint_Analysis.pm b/lib/Zarn/Engine/Taint_Analysis.pm
index 72276ca..2fd8971 100644
--- a/lib/Zarn/Engine/Taint_Analysis.pm
+++ b/lib/Zarn/Engine/Taint_Analysis.pm
@@ -4,7 +4,9 @@ package Zarn::Engine::Taint_Analysis {
     use PPI::Find;
     use Getopt::Long;
     use PPI::Document;
-    
+    use List::Util 'any';
+
+
     our $VERSION = '0.0.1';
 
     sub new {
@@ -13,31 +15,31 @@ package Zarn::Engine::Taint_Analysis {
 
         Getopt::Long::GetOptionsFromArray (
             $parameters,
-            "ast=s"   => \$ast,
-            "token=s" => \$token
+            'ast=s'   => \$ast,
+            'token=s' => \$token
         );
 
         if ($ast && $token) {
-            my $var_token = $ast -> find_first (                                
-                sub { 
-                    $_[1] -> isa("PPI::Token::Symbol") and 
+            my $var_token = $ast -> find_first (
+                sub {
+                    $_[1] -> isa('PPI::Token::Symbol') and
                     ($_[1] -> content eq "\$$token") # or $_[1] -> content eq "\@$1" or $_[1] -> content eq "\%$1"
                 }
             );
 
-            if ($var_token && $var_token -> can("parent")) {
+            if ($var_token && $var_token -> can('parent')) {
                 my @childrens = $var_token -> parent -> children;
-                
+
                 # verifyng if the variable is a fixed string or a number
-                if (grep { 
-                    $_ -> isa("PPI::Token::Quote::Double") || 
-                    $_ -> isa("PPI::Token::Quote::Single") || 
-                    $_ -> isa("PPI::Token::Number")
+                if (any {
+                    $_ -> isa('PPI::Token::Quote::Double') ||
+                    $_ -> isa('PPI::Token::Quote::Single') ||
+                    $_ -> isa('PPI::Token::Number')
                 } @childrens) {
                     return 0;
                 }
 
-                if (($var_token -> parent -> isa("PPI::Token::Operator") || $var_token -> parent -> isa("PPI::Statement::Expression"))) {
+                if (($var_token -> parent -> isa('PPI::Token::Operator') || $var_token -> parent -> isa('PPI::Statement::Expression'))) {
                     return $var_token -> location;
                 }
             }
diff --git a/lib/Zarn/Helper/Files.pm b/lib/Zarn/Helper/Files.pm
index 62b0be5..36fcdeb 100644
--- a/lib/Zarn/Helper/Files.pm
+++ b/lib/Zarn/Helper/Files.pm
@@ -3,24 +3,33 @@ package Zarn::Helper::Files {
     use warnings;
     use File::Find::Rule;
 
-    our $VERSION = '0.0.2';
+    our $VERSION = '0.0.3';
 
     sub new {
         my ($self, $source, $ignore) = @_;
 
         if ($source) {
             my $rule = File::Find::Rule -> new();
+            my $exclude_rule = $rule -> new();
 
-            $rule -> or (
-                $rule -> new -> directory -> name(".git", $ignore) -> prune -> discard,
-                $rule -> new
-            );
+            $exclude_rule = $exclude_rule -> directory();
+            $exclude_rule = $exclude_rule -> name('.git', $ignore);
+            $exclude_rule = $exclude_rule -> prune();
+            $exclude_rule = $exclude_rule -> discard();
+
+            my $file_rule = $rule -> new();
+            $rule -> or ($exclude_rule, $file_rule);
 
             $rule -> file -> nonempty;
-            $rule -> name("*.pm", "*.t", "*.pl");
+            $rule -> name('*.pm', '*.t', '*.pl');
 
             my @files = $rule -> in($source);
 
+            if (!@files) {
+                print "[!] Could not identify any files in: $source.\n";
+                return 1;
+            }
+
             return @files;
         }
 
diff --git a/lib/Zarn/Helper/Sarif.pm b/lib/Zarn/Helper/Sarif.pm
index c4f2257..aa1fda3 100644
--- a/lib/Zarn/Helper/Sarif.pm
+++ b/lib/Zarn/Helper/Sarif.pm
@@ -8,14 +8,14 @@ package Zarn::Helper::Sarif {
         my ($self, @vulnerabilities) = @_;
 
         my $sarif_data = {
-            "\$schema" => "https://raw.githubusercontent.com/oasis-tcs/sarif-spec/master/Schemata/sarif-schema-2.1.0.json",
-            version   => "2.1.0",
+            "\$schema" => 'https://raw.githubusercontent.com/oasis-tcs/sarif-spec/master/Schemata/sarif-schema-2.1.0.json',
+            version   => '2.1.0',
             runs      => [{
                 tool    => {
                     driver => {
-                        name    => "ZARN",
-                        informationUri => "https://github.com/htrgouvea/zarn",
-                        version => "0.1.0"
+                        name    => 'ZARN',
+                        informationUri =>'"https://github.com/htrgouvea/zarn',
+                        version => '0.1.0'
                     }
                 },
                 results => []
diff --git a/samples/code-injection.pl b/samples/code-injection.pl
deleted file mode 100644
index 129bcf7..0000000
--- a/samples/code-injection.pl
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/usr/bin/perl
- 
-use 5.018;
-use strict;
-use warnings;
-
-sub main {
-    my $name = $ARGV[0];
-
-    system ("echo Hello World! $name");
-}
-
-exit main();
\ No newline at end of file
diff --git a/samples/false-positive.pl b/samples/false-positive.pl
deleted file mode 100644
index 18eddd3..0000000
--- a/samples/false-positive.pl
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/usr/bin/perl
- 
-use 5.018;
-use strict;
-use warnings;
-
-sub main {
-    my $name = "Zarn";
-    
-    system ("echo Hello World! $name");
-}
-
-exit main();
\ No newline at end of file
diff --git a/tests/Files.t b/tests/Files.t
new file mode 100644
index 0000000..5a842b7
--- /dev/null
+++ b/tests/Files.t
@@ -0,0 +1,52 @@
+use strict;
+use warnings;
+use Test::More;
+use File::Temp qw(tempdir);
+use File::Path qw(make_path);
+use File::Spec;
+use File::Basename;
+use File::Find;
+use File::Slurp;
+use Zarn::Helper::Files;
+
+my $temp_dir = tempdir(CLEANUP => 1);
+
+my @dirs = (
+    File::Spec->catdir($temp_dir, 'dir1'),
+    File::Spec->catdir($temp_dir, 'dir2', '.git'),
+);
+
+my @files = (
+    File::Spec->catfile($temp_dir, 'dir1', 'file1.pm'),
+    File::Spec->catfile($temp_dir, 'dir1', 'file2.t'),
+    File::Spec->catfile($temp_dir, 'dir1', 'file3.pl'),
+    File::Spec->catfile($temp_dir, 'dir2', 'file4.pm'),
+    File::Spec->catfile($temp_dir, 'dir2', 'file5.txt'),
+    File::Spec->catfile($temp_dir, 'dir2', '.git', 'file6.pm'),
+);
+
+foreach my $dir (@dirs) {
+    make_path($dir);
+}
+
+foreach my $file (@files) {
+    write_file($file, "use strict;\n");
+}
+
+my @expected_files = (
+    File::Spec->catfile($temp_dir, 'dir1', 'file1.pm'),
+    File::Spec->catfile($temp_dir, 'dir1', 'file2.t'),
+    File::Spec->catfile($temp_dir, 'dir1', 'file3.pl'),
+    File::Spec->catfile($temp_dir, 'dir2', 'file4.pm'),
+);
+
+my @found_files = Zarn::Helper::Files->new($temp_dir, '.git');
+@found_files = sort @found_files;
+@expected_files = sort @expected_files;
+
+is_deeply(\@found_files, \@expected_files, 'Perl files correctly found in the source directory');
+
+my $no_source = Zarn::Helper::Files->new();
+is($no_source, 0, 'Returns 0 when no source directory is provided');
+
+done_testing();
\ No newline at end of file
diff --git a/tests/Rules.t b/tests/Rules.t
new file mode 100644
index 0000000..fe95846
--- /dev/null
+++ b/tests/Rules.t
@@ -0,0 +1,29 @@
+use strict;
+use warnings;
+use Test::More;
+use Zarn::Helper::Rules;
+use File::Temp qw(tempfile);
+
+my $yaml_content = <<'END_YAML';
+---
+rules:
+  - rule1
+  - rule2
+  - rule3
+END_YAML
+
+
+my ($fh, $filename) = tempfile();
+print $fh $yaml_content;
+close $fh;
+
+my @expected_rules = ('rule1', 'rule2', 'rule3');
+my @rules = Zarn::Helper::Rules->new($filename);
+
+my @flattened_rules = map { @$_ } @rules;
+is_deeply(\@flattened_rules, \@expected_rules, 'Rules correctly loaded from YAML file');
+
+my $no_rules = Zarn::Helper::Rules->new();
+is($no_rules, 0, 'Returns 0 when no rules file is provided');
+
+done_testing();
\ No newline at end of file
diff --git a/tools/graph.pl b/tools/graph.pl
deleted file mode 100644
index 57aa019..0000000
--- a/tools/graph.pl
+++ /dev/null
@@ -1,21 +0,0 @@
-#!/usr/bin/env perl
-
-use 5.018;
-use strict;
-use warnings;
-use Devel::Graph;
-
-sub main {
-    my $file = $ARGV[0];
-
-    if ($file) {
-        my $grapher = Devel::Graph -> new();
-        my $decompose   = $grapher -> decompose ($file);
-       
-        print $decompose -> as_ascii();
-    }
-
-    return 0;
-}
-
-exit main();
\ No newline at end of file
diff --git a/tools/view-ast.pl b/tools/view-ast.pl
deleted file mode 100644
index 44efe68..0000000
--- a/tools/view-ast.pl
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/usr/bin/env perl
-
-use 5.030;
-use strict;
-use warnings;
-use PPI;
-use Data::Dumper;
-
-sub main {
-    my $file = $ARGV[0];
-
-    if ($file) {
-        my $document = PPI::Document -> new($file);
-        print Dumper($document);
-    }
-}
-
-main();
\ No newline at end of file
diff --git a/zarn.pl b/zarn.pl
index 0dbe00c..4ea7a6f 100755
--- a/zarn.pl
+++ b/zarn.pl
@@ -5,7 +5,7 @@
 use warnings;
 use Carp;
 use JSON;
-use lib "./lib/";
+use lib './lib/';
 use Getopt::Long;
 use Zarn::Engine::AST;
 use Zarn::Helper::Files;
@@ -16,45 +16,47 @@
 our $VERSION = '0.1.0';
 
 sub main {
-    my $rules = "rules/default.yml";
-    my ($source, $ignore, $sarif, @results);
-
-    Getopt::Long::GetOptions (
-        "r|rules=s"   => \$rules,
-        "s|source=s"  => \$source,
-        "i|ignore=s"  => \$ignore,
-        "srf|sarif=s" => \$sarif
+    my $rules = 'rules/default.yml';
+    my ( $source, $ignore, $sarif, @results );
+
+    Getopt::Long::GetOptions(
+        'r|rules=s'   => \$rules,
+        's|source=s'  => \$source,
+        'i|ignore=s'  => \$ignore,
+        'srf|sarif=s' => \$sarif
     );
 
-    if (!$source) {
+    if ( !$source ) {
         print "\nZarn v0.1.0"
-        . "\nCore Commands"
-        . "\n==============\n"
-        . "\tCommand          Description\n"
-        . "\t-------          -----------\n"
-        . "\t-s, --source     Configure a source directory to do static analysis\n"
-        . "\t-r, --rules      Define YAML file with rules\n"
-        . "\t-i, --ignore     Define a file or directory to ignore\n"
-        . "\t-srf, --sarif    Define the SARIF output file\n"
-        . "\t-h, --help       To see help menu of a module\n\n";
+            . "\nCore Commands"
+            . "\n==============\n"
+            . "\tCommand          Description\n"
+            . "\t-------          -----------\n"
+            . "\t-s, --source     Configure a source directory to do static analysis\n"
+            . "\t-r, --rules      Define YAML file with rules\n"
+            . "\t-i, --ignore     Define a file or directory to ignore\n"
+            . "\t-srf, --sarif    Define the SARIF output file\n"
+            . "\t-h, --help       To see help menu of a module\n\n";
 
         return 0;
     }
 
-    my @rules = Zarn::Helper::Rules -> new($rules);
-    my @files = Zarn::Helper::Files -> new($source, $ignore);
+    my @rules = Zarn::Helper::Rules->new($rules);
+    my @files = Zarn::Helper::Files->new($source, $ignore);
 
     foreach my $file (@files) {
         if (@rules) {
-            my $ast = Zarn::Engine::AST -> new (["--file" => $file]);
+            my $ast = Zarn::Engine::AST->new( ['--file' => $file] );
 
-            my @analysis = Zarn::Engine::Source_to_Sink -> new ([
-                "--ast" => $ast,
-                "--rules" => @rules
-            ]);
+            my @analysis = Zarn::Engine::Source_to_Sink->new(
+                [
+                    '--ast'   => $ast,
+                    '--rules' => @rules
+                ]
+            );
 
             if (@analysis) {
-                $analysis[0] -> {'file'} = $file;
+                $analysis[0]->{'file'} = $file;
             }
 
             push @results, @analysis;
@@ -62,28 +64,27 @@ sub main {
     }
 
     foreach my $result (@results) {
-        my $category       = $result -> {category};
-        my $file           = $result -> {file};
-        my $title          = $result -> {title};
-        my $line_sink      = $result -> {line_sink};
-        my $rowchar_sink   = $result -> {rowchar_sink};
-        my $line_source    = $result -> {line_source};
-        my $rowchar_source = $result -> {rowchar_source};
-
-        print "[$category] - FILE:$file \t Potential: $title. \t Dangerous function on line: $line_sink:$rowchar_sink \t Data point possibility controlled: $line_source:$rowchar_source\n";
+        my $category       = $result->{category};
+        my $file           = $result->{file};
+        my $title          = $result->{title};
+        my $line_sink      = $result->{line_sink};
+        my $rowchar_sink   = $result->{rowchar_sink};
+        my $line_source    = $result->{line_source};
+        my $rowchar_source = $result->{rowchar_source};
+
+        print
+            "[$category] - FILE:$file \t Potential: $title. \t Dangerous function on line: $line_sink:$rowchar_sink \t Data point possibility controlled: $line_source:$rowchar_source\n";
     }
 
     if ($sarif) {
-        my $sarif_data = Zarn::Helper::Sarif -> new (@results);
+        my $sarif_data = Zarn::Helper::Sarif->new(@results);
 
-        open(my $output, '>', $sarif) or croak "Cannot open file '$sarif': $!";
-        
+        open( my $output, '>', $sarif ) or croak "Cannot open the $sarif file\n";
         print $output encode_json($sarif_data);
-        
-        close($output);
+        close($output) or die "Error to close the file\n";
     }
 
     return 0;
 }
 
-main();
+main();
\ No newline at end of file