From b9297e004a2347307543ee711ad61cbd94964b6d Mon Sep 17 00:00:00 2001
From: Lisa Georgiades <g33kgrrl@users.noreply.github.com>
Date: Thu, 13 Jul 2017 10:12:18 -0700
Subject: [PATCH] Factors: Add support for negative numbers. Add negative cases
 and tidy (#4245) (#4299)

* Add support for negative numbers. Add negative cases and tidy (#4245)

* Remove extraneous regex match
---
 lib/DDG/Goodie/Factors.pm | 24 +++++++++++-----
 t/Factors.t               | 59 +++++++++++++++++++++++++++++----------
 2 files changed, 61 insertions(+), 22 deletions(-)

diff --git a/lib/DDG/Goodie/Factors.pm b/lib/DDG/Goodie/Factors.pm
index 66b6a7b6d2d..982c0694b0a 100755
--- a/lib/DDG/Goodie/Factors.pm
+++ b/lib/DDG/Goodie/Factors.pm
@@ -1,4 +1,5 @@
 package DDG::Goodie::Factors;
+
 # ABSTRACT: Returns the factors of the entered number
 
 use strict;
@@ -13,18 +14,27 @@ triggers startend => 'factors', 'factors of';
 
 handle remainder => sub {
     my $query = $_;
-    return unless $query =~ /^\d+$/;
 
-    my $factors = join ', ', divisors($query);
+    return unless $query =~ /^(-)?(\d+)$/;
+
+    # The divisors method cannot handle negative numbers, so find the
+    # query magnitude and call it with that instead. Then if the
+    # query number is negative, find and include negative factors.
+    my $negative  = $1;
+    my $query_mag = $2;
+    my @factors   = divisors($query_mag);
+
+    unshift @factors, sort { $a <=> $b } map { -$_ } @factors
+        if $negative;
+
+    my $factors_list = join ', ', @factors;
 
-    return "Factors of $query: $factors", structured_answer => {
+    return "Factors of $query: $factors_list", structured_answer => {
         data => {
-            title => $factors,
+            title    => $factors_list,
             subtitle => "Factors of: $query"
         },
-        templates => {
-            group => 'text'
-        }
+        templates => { group => 'text' }
     };
 };
 
diff --git a/t/Factors.t b/t/Factors.t
index 289df363fbf..92c817c2f91 100755
--- a/t/Factors.t
+++ b/t/Factors.t
@@ -9,26 +9,55 @@ use DDG::Test::Goodie;
 zci answer_type => "factors";
 zci is_cached   => 1;
 
-sub build_test
-{
-    my ($text_answer, $input, $answer) = @_;
-    return test_zci($text_answer, structured_answer =>{
-        data => {
-            title => $answer,
-            subtitle => "Factors of: $input"
-        },
-        templates => {
-            group => 'text'
+sub build_test {
+    my ( $text_answer, $input, $answer ) = @_;
+
+    return test_zci(
+        $text_answer,
+        structured_answer => {
+            data => {
+                title    => $answer,
+                subtitle => "Factors of: $input"
+            },
+            templates => { group => 'text' }
         }
-    });
+    );
 }
 
 ddg_goodie_test(
     [qw( DDG::Goodie::Factors)],
-    '30 factors'    => build_test('Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30', '30', '1, 2, 3, 5, 6, 10, 15, 30'),
-    'factors of 72' => build_test('Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72', '72', '1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72'),
-    'factors of 30' => build_test('Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30', '30', '1, 2, 3, 5, 6, 10, 15, 30'),
-    '72 factors'    => build_test('Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72', '72', '1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72'),
+    '30 factors' => build_test(
+        'Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30',
+        '30',
+        '1, 2, 3, 5, 6, 10, 15, 30'
+    ),
+    'factors of 72' => build_test(
+        'Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72',
+        '72',
+        '1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72'
+    ),
+    'factors of 30' => build_test(
+        'Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30',
+        '30',
+        '1, 2, 3, 5, 6, 10, 15, 30'
+    ),
+    '72 factors' => build_test(
+        'Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72',
+        '72',
+        '1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72'
+    ),
+    'factors of -6' => build_test(
+        'Factors of -6: -6, -3, -2, -1, 1, 2, 3, 6',
+        '-6',
+        '-6, -3, -2, -1, 1, 2, 3, 6'
+    ),
+    '-12 factors' => build_test(
+        'Factors of -12: -12, -6, -4, -3, -2, -1, 1, 2, 3, 4, 6, 12',
+        '-12',
+        '-12, -6, -4, -3, -2, -1, 1, 2, 3, 4, 6, 12'
+    ),
+    'factors of 2.4'  => undef,
+    'factors of fear' => undef,
 );
 
 done_testing;