1 files changed, 51 insertions, 0 deletions
diff --git a/t/30-hashref-alteration.t b/t/30-hashref-alteration.t
new file mode 100644
index 0000000..116353f
--- /dev/null
+++ b/t/30-hashref-alteration.t
@@ -0,0 +1,51 @@
+use strict;
+use warnings;
+use Test::More;
+
+use Params::Validate qw( validate SCALAR );
+
+{
+    my $p = { foo => 1 };
+
+    val($p);
+
+    is_deeply(
+        $p, { foo => 1 },
+        'validate does not alter hashref passed to val'
+    );
+
+    val2($p);
+
+    is_deeply(
+        $p, { foo => 1 },
+        'validate does not alter hashref passed to val, even with defaults being supplied'
+    );
+}
+
+sub val {
+    validate(
+        @_, {
+            foo => { optional => 1 },
+            bar => { optional => 1 },
+            baz => { optional => 1 },
+            buz => { optional => 1 },
+        },
+    );
+
+    return;
+}
+
+sub val2 {
+    validate(
+        @_, {
+            foo => { optional => 1 },
+            bar => { default  => 42 },
+            baz => { optional => 1 },
+            buz => { optional => 1 },
+        },
+    );
+
+    return;
+}
+
+done_testing();