1 files changed, 40 insertions, 0 deletions
diff --git a/t/shared-letters.t b/t/shared-letters.t
new file mode 100644
index 0000000..238ed23
--- /dev/null
+++ b/t/shared-letters.t
@@ -0,0 +1,40 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use Test::More;
+
+use Games::Word qw(shared_letters shared_letters_by_position);
+
+my @tests = (
+    {a => "abcde", b => "edcba", sl => 5, slbp => 1,
+     slbp_full => [undef, undef, 'c', undef, undef]},
+    {a => "",      b => "",      sl => 0, slbp => 0,
+     slbp_full => []},
+    {a => "",      b => "abcde", sl => 0, slbp => 0,
+     slbp_full => [undef, undef, undef, undef, undef]},
+    {a => "aaa",   b => "aa",    sl => 2, slbp => 2,
+     slbp_full => ['a', 'a', undef]},
+    {a => "abc",   b => "abcde", sl => 3, slbp => 3,
+     slbp_full => ['a', 'b', 'c', undef, undef]},
+    {a => "cde",   b => "abcde", sl => 3, slbp => 0,
+     slbp_full => [undef, undef, undef, undef, undef]},
+    {a => "abcba", b => "aabbc", sl => 5, slbp => 2,
+     slbp_full => ['a', undef, undef, 'b', undef]},
+    {a => "abcde", b => "cdefg", sl => 3, slbp => 0,
+     slbp_full => [undef, undef, undef, undef, undef]},
+    {a => "bacaa", b => "gabca", sl => 4, slbp => 2,
+     slbp_full => [undef, 'a', undef, undef, 'a']},
+);
+
+for (@tests) {
+    my %test = %$_;
+    my ($a, $b) = ($test{a}, $test{b});
+    is(shared_letters($a, $b), $test{sl},
+       "testing shared_letters: '$a' vs '$b'");
+    is(shared_letters_by_position($a, $b), $test{slbp},
+       "testing shared_letters_by_position: '$a' vs '$b'");
+    is_deeply([shared_letters_by_position($a, $b)], $test{slbp_full},
+       "testing shared_letters_by_position (list): '$a' vs '$b'");
+}
+
+done_testing;