Revamp t/85-stress-unwind.t

Stop using eval() to compute the expected value. This highlighted an issue
with how list() was defined.

This test now runs about 25% faster.

diff --git a/t/85-stress-unwind.t b/t/85-stress-unwind.t
index fa52bcd07b34eb83e22d7cf6505610298a5dda76..8ee79c6ec16d5ee733807e625377d2c5397ec714 100644 (file)
--- a/t/85-stress-unwind.t
+++ b/t/85-stress-unwind.t
@@ -8,15 +8,18 @@ use Test::Leaner 'no_plan';
 
 use Scope::Upper qw<unwind UP HERE>;
 
-our ($call, @args, $args);
+our ($call, @args);
 
 $call = sub {
  my ($height, $level, $i) = @_;
  $level = $level ? 'UP ' x $level : 'HERE';
- return [ [ "unwind(\@args => $level)\n", '' ] ];
+ return [ [ "unwind(\@args => $level)\n", [ \@args ] ] ];
 };
 
-sub list { @_ }
+# @_[0 .. $#_] also ought to work, but it sometimes evaluates to nonsense in
+# scalar context on perl 5.8.5 and below.
+
+sub list { wantarray ? @_ : $_[$#_] }
 
 my @blocks = (
  [ 'sub {',     '}->()' ],
@@ -24,36 +27,49 @@ my @blocks = (
 );
 
 my @contexts = (
- [ '',        '; ()' ],
- [ 'scalar(', ')' ],
- [ 'list(',   ')' ],
+ [ '',        '; ()', 'v' ],
+ [ 'scalar(', ')',    's' ],
+ [ 'list(',   ')',    'l' ],
 );
 
-@blocks   = map [ map "$_\n", @$_ ], @blocks;
-@contexts = map [ map "$_\n", @$_ ], @contexts;
+for my $block (@blocks) {
+ $_ .= "\n" for @$block[0, 1];
+}
+for my $cxt (@contexts) {
+ $_ .= "\n" for @$cxt[0, 1];
+}
+
+sub contextify {
+ my ($cxt, $active, $exp, @items) = @_;
+ return $exp unless $active;
+ if ($cxt eq 'v') {
+  return [ ];
+ } elsif ($cxt eq 's') {
+  return [ $cxt, @$exp ];
+ } else {
+  return [ @items, @$exp ];
+ }
+}
 
 sub gen {
  my ($height, $level, $i) = @_;
  push @_, $i = 0 if @_ == 2;
  my @res;
  my $up = $i == $height + 1 ? $call->(@_) : gen($height, $level, $i + 1);
- if ($i + $level == $height + 1) {
-  for (@$up) {
-   $_->[1] = "return($args)\n";
-  }
- }
+ my $active = $i <= ($height - $level);
  for my $base (@$up) {
   my ($code, $exp) = @$base;
   for my $blk (@blocks) {
    for my $cx (@contexts) {
     push @res, [
      $blk->[0] . $cx->[0] . $code . $cx->[1] . $blk->[1],
-     $blk->[0] . $cx->[0] . $exp .  $cx->[1] . $blk->[1],
+     contextify($cx->[2], $active, $exp),
     ];
-    my $list = join ', ', map { int rand 10 } 0 .. rand 3;
+    my @items = map { int rand 10 } 0 .. rand 3;
+    my $list  = join ', ', @items;
     push @res, [
-     $blk->[0] . $cx->[0] . "($list, " . $code . ')' . $cx->[1] . $blk->[1],
-     $blk->[0] . $cx->[0] . "($list, " . $exp .  ')' . $cx->[1] . $blk->[1],
+     $blk->[0] . $cx->[0] . "($list, $code)" . $cx->[1] . $blk->[1],
+     contextify($cx->[2], $active, $exp, @items),
     ];
    }
   }
@@ -63,6 +79,23 @@ sub gen {
 
 sub linearize { join ', ', map { defined($_) ? $_ : '(undef)' } @_ }
 
+sub expect {
+ my @spec = @{$_[0]};
+ my @acc;
+ for my $s (reverse @spec) {
+  if (ref $s) {
+   unshift @acc, @$s;
+  } elsif ($s =~ /^[0-9]+$/) {
+   unshift @acc, $s;
+  } elsif ($s eq 's') {
+   @acc = (@acc ? $acc[-1] : undef);
+  } else {
+   return 'XXX';
+  }
+ }
+ return linearize @acc;
+}
+
 sub runtests {
  my ($height, $level) = @_;
  my $i;
@@ -71,13 +104,13 @@ sub runtests {
   ++$i;
   no warnings 'void';
   my $res = linearize eval $_->[0];
-  $res = '*TEST DID NOT COMPILE*' if $@;
   my $exp;
-  unless ($@) {
-   $exp = linearize eval $_->[1];
-   $exp = '*REFERENCE DID NOT COMPILE*' if $@;
+  if ($@) {
+   $res = '*TEST DID NOT COMPILE*';
+  } else {
+   $exp = expect $_->[1];
   }
-  if ($@ || $res ne $exp) {
+  if ($res ne $exp) {
    diag <<DIAG;
 === This testcase failed ===
 $_->[0];
@@ -90,7 +123,6 @@ DIAG
 
 for ([ ], [ 'A' ], [ qw<B C> ]) {
  @args = @$_;
- $args = '(' . join(', ', map "'$_'", @args) . ')';
  runtests 0, 0;
  runtests 0, 1;
  runtests 1, 0;