Fixed PercentOf.t and minor bugs on .pm file

lib/DDG/Goodie/PercentOf.pm

@@ -0,0 +1,49 @@
+package DDG::Goodie::PercentOf;
+# Operations with percentuals
+
+use DDG::Goodie;
+
+zci answer_type => "percent_of";
+zci is_cached   => 1;
+
+name "PercentOf";
+description "Makes Operations with percentuals";
+primary_example_queries "4-50%", "349*16%";
+
+code_url "https://github.com/duckduckgo/zeroclickinfo-goodies/blob/master/lib/DDG/Goodie/PercentOf/PercentOf.pm";
+attribution github => ["puskin94", "puskin"],
+            twitter => "twitterhandle";
+
+my $result;
+
+triggers query_nowhitespace => qr/\d{1,3}\%$/;
+
+handle query_nowhitespace => sub {
+
+    my $input = $_;
+
+    return unless $input =~ qr/(\d+)(\+|\*|\/|\-)(\d+)\%/;
+
+
+    if ($2 eq '-') {
+        $result = ( $1 - (($1 * $3) / 100) );
+    } elsif ($2 eq '+') {
+        $result = ( $1 + (($1 * $3) / 100) );
+    } elsif ($2 eq '*') {
+        $result = ( $1 * (($1 * $3) / 100) );
+    } elsif ($2 eq '/') {
+        $result = ( $1 / (($1 * $3) / 100) );
+    }
+
+    my $text = "Result: $result";
+    return $text,
+    structured_answer => {
+        input => [$input],
+        operation => 'Calculate',
+        result => $result
+    };
+
+};
+
+1;
+

t/PercentOf.t

@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use Test::More;
+use DDG::Test::Goodie;
+
+zci answer_type => "percent_of";
+zci is_cached   => 1;
+
+ddg_goodie_test(
+    [qw( DDG::Goodie::PercentOf )],
+
+    '4+50%' => test_zci('Result: 6',
+        structured_answer => {
+            input => ["4+50%"],
+            operation => "Calculate",
+            result => 6
+        }),
+
+    '456+120%' => test_zci('Result: 1003.2',
+        structured_answer => {
+            input => ["456+120%"],
+            operation => "Calculate",
+            result => 1003.2
+        }),
+
+    'urldecode hello%20there' => undef,
+    '34$+16' => undef,
+    '12+5t%' => undef
+);
+
+done_testing;