Index: t/op/join.t
===================================================================
--- t/op/join.t	(revision 196)
+++ t/op/join.t	(working copy)
@@ -1,9 +1,26 @@
 use v6;
 
-say "1..1";
+say "1..6";
 
-if (["a", "b", "c"].join("|") eq "a|b|c") {
-    say "ok 1 # TODO"
-} else {
-    say "not ok 1 # TODO"
-}
+# test all variants of join() 
+
+my $a = ["a", "b", "c"].join("|");
+if ($a eq "a|b|c") { say "ok 1"; } else { say "not ok 1 # TODO [].join()"; }
+
+my $b = ("a", "b", "c").join("|");
+if ($b eq "a|b|c") { say "ok 2"; } else { say "not ok 2 # TODO ().join()"; }
+
+my @list_c = ("a", "b", "c");
+my $c = @list_c.join("|");
+if ($c eq "a|b|c") { say "ok 3"; } else { say "not ok 3 # TODO @list.join()"; }
+
+my @list_d = ("a", "b", "c");
+my $d = join("|", @list_d);
+if ($d eq "a|b|c") { say "ok 4"; } else { say "not ok 4"; }
+
+my $e = join("|", "a", "b", "c");
+if ($e eq "a|b|c") { say "ok 5"; } else { say "not ok 5"; }
+
+my $f = join("|", [ "a", "b", "c" ]);
+if ($f eq "a|b|c") { say "ok 6"; } else { say "not ok 6"; }
+