+my %cached_scripts;
+sub key2script ($) {
+ my ($key) = @_;
+ return $key if $key =~ m!\A/!;
+ # n.b. we may have scripts which don't start with "public-inbox" in
+ # the future:
+ $key =~ s/\A([-\.])/public-inbox$1/;
+ 'blib/script/'.$key;
+}
+
+sub _prepare_redirects ($) {
+ my ($fhref) = @_;
+ my @x = ([ \*STDIN, '<&' ], [ \*STDOUT, '>&' ], [ \*STDERR, '>&' ]);
+ for (my $fd = 0; $fd <= $#x; $fd++) {
+ my $fh = $fhref->[$fd] or next;
+ my ($oldfh, $mode) = @{$x[$fd]};
+ open $oldfh, $mode, $fh or die "$$oldfh $mode redirect: $!";
+ }
+}
+
+# $opt->{run_mode} (or $ENV{TEST_RUN_MODE}) allows chosing between
+# three ways to spawn our own short-lived Perl scripts for testing:
+#
+# 0 - (fork|vfork) + execve, the most realistic but slowest
+# 1 - preloading and running in a forked subprocess (fast)
+# 2 - preloading and running in current process (slightly faster than 1)
+#
+# 2 is not compatible with scripts which use "exit" (which we'll try to
+# avoid in the future).
+# The default is 2.
+our $run_script_exit_code;
+sub RUN_SCRIPT_EXIT () { "RUN_SCRIPT_EXIT\n" };
+sub run_script_exit (;$) {
+ $run_script_exit_code = $_[0] // 0;
+ die RUN_SCRIPT_EXIT;
+}
+
+sub run_script ($;$$) {
+ my ($cmd, $env, $opt) = @_;
+ my ($key, @argv) = @$cmd;
+ my $run_mode = $ENV{TEST_RUN_MODE} // $opt->{run_mode} // 1;
+ my $sub = $run_mode == 0 ? undef : ($cached_scripts{$key} //= do {
+ my $f = key2script($key);
+ open my $fh, '<', $f or die "open $f: $!";
+ my $str = do { local $/; <$fh> };
+ my ($fc, $rest) = ($key =~ m/([a-z])([a-z0-9]+)\z/);
+ $fc = uc($fc);
+ my $pkg = "PublicInbox::TestScript::$fc$rest";
+ eval <<EOF;
+package $pkg;
+use strict;
+use subs qw(exit);
+
+*exit = *::run_script_exit;
+sub main {
+$str
+ 0;
+}
+1;
+EOF
+ $pkg->can('main');
+ }); # do
+
+ my $fhref = [];
+ my $spawn_opt = {};
+ for my $fd (0..2) {
+ my $redir = $opt->{$fd};
+ next unless ref($redir);
+ open my $fh, '+>', undef or die "open: $!";
+ $fhref->[$fd] = $fh;
+ $spawn_opt->{$fd} = fileno($fh);
+ next if $fd > 0;
+ $fh->autoflush(1);
+ print $fh $$redir or die "print: $!";
+ seek($fh, 0, SEEK_SET) or die "seek: $!";
+ }
+ if ($run_mode == 0) {
+ # spawn an independent new process, like real-world use cases:
+ require PublicInbox::Spawn;
+ my $cmd = [ key2script($key), @argv ];
+ my $pid = PublicInbox::Spawn::spawn($cmd, $env, $spawn_opt);
+ defined($pid) or die "spawn: $!";
+ if (defined $pid) {
+ my $r = waitpid($pid, 0);
+ defined($r) or die "waitpid: $!";
+ $r == $pid or die "waitpid: expected $pid, got $r";
+ }
+ } else { # localize and run everything in the same process:
+ local *STDIN = *STDIN;
+ local *STDOUT = *STDOUT;
+ local *STDERR = *STDERR;
+ local %ENV = $env ? (%ENV, %$env) : %ENV;
+ local %SIG = %SIG;
+ _prepare_redirects($fhref);
+ local @ARGV = @argv;
+ $run_script_exit_code = undef;
+ my $exit_code = eval { $sub->(@argv) };
+ if ($@ eq RUN_SCRIPT_EXIT) {
+ $@ = '';
+ $exit_code = $run_script_exit_code;
+ $? = ($exit_code << 8);
+ } elsif (defined($exit_code)) {
+ $? = ($exit_code << 8);
+ } elsif ($@) { # mimic die() behavior when uncaught
+ warn "E: eval-ed $key: $@\n";
+ $? = ($! << 8) if $!;
+ $? = (255 << 8) if $? == 0;
+ } else {
+ die "BUG: eval-ed $key: no exit code or \$@\n";
+ }
+ }
+
+ # slurp the redirects back into user-supplied strings
+ for my $fd (1..2) {
+ my $fh = $fhref->[$fd] or next;
+ seek($fh, 0, SEEK_SET) or die "seek: $!";
+ my $redir = $opt->{$fd};
+ local $/;
+ $$redir = <$fh>;
+ }
+ $? == 0;
+}
+