io: introduce write_file helper sub

This is pretty convenient way to create files for diff
generation in both WWW and lei.  The test suite should also be
able to take advantage of it.

1 files changed, 33 insertions, 0 deletions

diff --git a/t/io.t b/t/io.t
new file mode 100644
index 00000000..4c7a97a3
--- /dev/null
+++ b/t/io.t
@@ -0,0 +1,33 @@
+#!perl -w
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use v5.12;
+use PublicInbox::TestCommon;
+my $tmpdir = tmpdir;
+use_ok 'PublicInbox::IO';
+use PublicInbox::Spawn qw(which run_qx);
+
+# only test failures
+SKIP: {
+skip 'linux only test' if $^O ne 'linux';
+my $strace = which('strace') or skip 'strace missing for test';
+my $v = run_qx([$strace, '--version']);
+$v =~ m!version\s+([1-9]+\.[0-9]+)! or xbail "no strace --version: $v";
+$v = eval("v$1");
+$v ge v4.16 or skip "$strace too old for syscall injection (".
+                sprintf('v%vd', $v). ' < v4.16)';
+my $env = { PERL5LIB => join(':', @INC) };
+my $opt = { 1 => \my $out, 2 => \my $err };
+my $dst = "$tmpdir/dst";
+my $tr = "$tmpdir/tr";
+my $cmd = [ $strace, "-o$tr", "-P$dst",
+                '-e', 'inject=writev,write:error=EIO',
+                $^X, qw(-w -MPublicInbox::IO=write_file -e),
+                q[write_file '>', $ARGV[0], 'hello world'], $dst ];
+xsys($cmd, $env, $opt);
+isnt($?, 0, 'write failed');
+like($err, qr/\bclose\b/, 'close error noted');
+is(-s $dst, 0, 'file created and empty after EIO');
+} # /SKIP
+
+done_testing;