1 files changed, 39 insertions, 0 deletions
diff --git a/t/op/current_sub.t b/t/op/current_sub.t
new file mode 100644
index 0000000000..7a00032c46
--- /dev/null
+++ b/t/op/current_sub.t
@@ -0,0 +1,39 @@
+#!./perl
+
+BEGIN {
+    chdir 't';
+    @INC = qw(../lib);
+    require './test.pl';
+}
+
+plan tests => 11;
+
+is __SUB__, "__SUB__", '__SUB__ is a bareword outside of use feature';
+
+{
+    use v5.15;
+    is __SUB__, undef, '__SUB__ under use v5.16';
+}
+
+use feature 'current_sub';
+
+is __SUB__, undef, '__SUB__ returns undef outside of a subroutine';
+is +()=__SUB__, 1, '__SUB__ returns undef in list context';
+
+sub foo { __SUB__ }
+is foo, \&foo, '__SUB__ inside a named subroutine';
+is foo->(), \&foo, '__SUB__ is callable';
+is ref foo, 'CODE', '__SUB__ is a code reference';
+
+my $subsub = sub { __SUB__ };
+is &$subsub, $subsub, '__SUB__ inside anonymous non-closure';
+
+my @subsubs;
+for my $x(1..3) {
+  push @subsubs, sub { return $x if @_; __SUB__ };
+}
+# Don’t loop here; we need to avoid interactions between the iterator
+# and the closure.
+is $subsubs[0]()(0), 1, '__SUB__ inside closure (1)';
+is $subsubs[1]()(0), 2, '__SUB__ inside closure (2)';
+is $subsubs[2]()(0), 3, '__SUB__ inside closure (3)';