Starting on unit tests for build_regex

MANIFEST

@@ -78,6 +78,7 @@ t/anchored.t
 t/bad-ackrc-opt.t
 t/basic.t
 t/boolean.t
+t/build_regex.t
 t/command-line-files.t
 t/config-backwards-compat.t
 t/config-finder.t

t/build_regex.t

@@ -0,0 +1,73 @@
+#!perl
+
+use warnings;
+use strict;
+
+use Test::More tests => 4;
+
+use App::Ack;
+
+
+PLAIN: {
+    _check(
+        'foo',
+        {},
+        '(?-xism:foo)',
+        '(?m-xis:foo)',
+        'Nuthin fancy'
+    );
+}
+
+
+DASH_Q: {
+    _check(
+        'foo',
+        { Q => 1 },
+        '(?-xism:foo)',
+        '(?m-xis:foo)',
+        'Nothing for -Q to do'
+    );
+    _check(
+        'thing^ and ($foo)',
+        { Q => 1 },
+        '(?-xism:thing\^\ and\ \(\$foo\))',
+        undef,  # No scan regex when there are anchors
+        '-Q has things to escape'
+    );
+}
+
+
+DASH_i: {
+    _check(
+        'NeXT',
+        { i => 1 },
+        '(?-xism:(?i)NeXT)',
+        '(?m-xis:(?i)NeXT)',
+        'Simple -i'
+    );
+}
+
+
+exit 0;
+
+
+sub _check {
+    local $Test::Builder::Level = $Test::Builder::Level + 1;
+
+    my $str       = shift;
+    my $opt       = shift;
+    my $exp_match = shift;
+    my $exp_scan  = shift;
+    my $msg       = shift or die 'Must provide a message';
+
+    return subtest $msg => sub () {
+        $opt = { %{$opt} };
+
+        $opt->{$_} //= [] for qw( and or not );
+
+        my ($match, $scan) = App::Ack::build_regex( $str, $opt );
+
+        is( $match, $exp_match, 'match matches' );
+        is( $scan, $exp_scan, 'scan matches' );
+    };
+}