clarify the state of $_ in finally blocks

diff --git a/lib/Try/Tiny.pm b/lib/Try/Tiny.pm
index 795272e..17bcf80 100644 (file)
--- a/lib/Try/Tiny.pm
+++ b/lib/Try/Tiny.pm
@@ -289,8 +289,10 @@ you to locate cleanup code which cannot be done via C<local()> e.g. closing a fi
 handle.
 
 When invoked, the finally block is passed the error that was caught.  If no
-error was caught, it is passed nothing.  In other words, the following code
-does just what you would expect:
+error was caught, it is passed nothing.  (Note that the finally block does not
+localize C<$_> with the error, since unlike in a catch block, there is no way
+to know if C<$_ == undef> implies that there were no errors.) In other words,
+the following code does just what you would expect:
 
   try {
     die_sometimes();

diff --git a/t/finally.t b/t/finally.t
index 80af9e5..abfb9cb 100644 (file)
--- a/t/finally.t
+++ b/t/finally.t
@@ -3,7 +3,7 @@
 use strict;
 #use warnings;
 
-use Test::More tests => 13;
+use Test::More tests => 24;
 
 BEGIN { use_ok 'Try::Tiny' };
 
@@ -74,4 +74,31 @@ try {
     };
 };
 
+$_ = "foo";
+try {
+    is($_, "foo", "not localized in try");
+}
+catch {
+}
+finally {
+    is(scalar(@_), 0, "nothing in \@_ (finally)");
+    is($_, "foo", "\$_ not localized (finally)");
+};
+is($_, "foo", "same afterwards");
+
+$_ = "foo";
+try {
+    is($_, "foo", "not localized in try");
+    die "bar\n";
+}
+catch {
+    is($_[0], "bar\n", "error in \@_ (catch)");
+    is($_, "bar\n", "error in \$_ (catch)");
+}
+finally {
+    is(scalar(@_), 1, "error in \@_ (finally)");
+    is($_[0], "bar\n", "error in \@_ (finally)");
+    is($_, "foo", "\$_ not localized (finally)");
+};
+is($_, "foo", "same afterwards");
 1;