test(harness): port harness self-tests to Perl

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

3 files changed, 66 insertions, 46 deletions

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 9f755a6..1a20f38 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -3,8 +3,8 @@ find_package(Perl REQUIRED)
 set(CPSC_TEST_SEED "" CACHE STRING "Replay seed (defaults to HEAD at test execution)")
 set(CPSC_TEST_COUNT 10000 CACHE STRING "Random records per differential group")
 
-add_test(NAME harness COMMAND "${Python3_EXECUTABLE}"
-    "${CMAKE_CURRENT_SOURCE_DIR}/test_runner.py")
+add_test(NAME harness COMMAND "${PERL_EXECUTABLE}"
+    "${CMAKE_CURRENT_SOURCE_DIR}/test_runner.pl")
 add_test(NAME generators COMMAND "${PERL_EXECUTABLE}"
     "${CMAKE_CURRENT_SOURCE_DIR}/check_generators.pl" "${PERL_EXECUTABLE}")
 foreach(suite i ii iii)
diff --git a/tests/test_runner.pl b/tests/test_runner.pl
new file mode 100644
index 0000000..af08556
--- /dev/null
+++ b/tests/test_runner.pl
@@ -0,0 +1,64 @@
+#!/usr/bin/env perl
+# Small contract checks for the test harness, including intentional failures.
+use strict;
+use warnings;
+use File::Spec;
+use File::Temp qw(tempdir);
+use FindBin;
+use JSON::PP ();
+use Test::More;
+
+require File::Spec->catfile($FindBin::Bin, 'run.pl');
+
+eval { compare("a\nb\n", "a\r\nb\r\n", 'stdout'); };
+ok(!$@, 'CRLF-only difference is accepted');
+for my $bad ("a\nb", "a \nb\n", "A\nb\n", "a\n\nb\n") {
+    my $ok = eval { compare("a\nb\n", $bad, 'stdout'); 1; };
+    ok(!$ok, 'strict output rejects ' . show_bytes($bad));
+}
+
+for my $case ([1, ''], [-11, ''], [0, 'unexpected']) {
+    my ($code, $stderr) = @{$case};
+    my $ok = eval {
+        check_result({returncode => $code, stdout => "ok\n", stderr => $stderr}, "ok\n");
+        1;
+    };
+    ok(!$ok, "exit code $code with stderr " . show_bytes($stderr) . ' fails');
+}
+
+my $good = {
+    returncode => 1,
+    stdout     => '',
+    stderr     => "error: Expected ':' at line 3\ncompilation terminated.\n",
+};
+my $accepted = eval {
+    check_diagnostics($good, [{reason => "Expected ':'", line => 3}]);
+    1;
+};
+ok($accepted, 'matching reason and location accepted');
+for my $bad (
+    "error: Expected ':' at line 4",
+    "error: Expected ':'",
+    "error: Expected ':' at line 30\nerror: unrelated at line 3",
+    )
+{
+    my $ok = eval {
+        check_diagnostics(
+            {returncode => 1, stdout => '', stderr => $bad . "\ncompilation terminated.\n"},
+            [{reason => "Expected ':'", line => 3}],
+        );
+        1;
+    };
+    ok(!$ok, 'diagnostic mismatch rejected: ' . show_bytes($bad));
+}
+
+my $dir = tempdir(CLEANUP => 1);
+my $state = commands_new($dir);
+my $ran = eval { run_command($state, [$^X, '-e', 'sleep 5'], $dir, '', 1); 1; };
+my $timed_out = "$@";
+ok(!$ran, 'overlong command fails');
+like($timed_out, qr/timed out/, 'timeout message names the cause');
+my $metadata = JSON::PP->new->decode(read_file(File::Spec->catfile($dir, '01.json')));
+ok($metadata->{timeout_expired}, 'timeout recorded in command metadata');
+
+done_testing();
diff --git a/tests/test_runner.py b/tests/test_runner.py
deleted file mode 100644
index 9558175..0000000
--- a/tests/test_runner.py
+++ /dev/null
@@ -1,44 +0,0 @@
-"""Small contract checks for the test harness, including intentional failures."""
-
-from pathlib import Path
-import subprocess
-import sys
-import tempfile
-import unittest
-
-from run import Commands, Failure, check_diagnostics, check_result, compare
-
-
-class HarnessTests(unittest.TestCase):
-    def test_strict_output(self):
-        compare(b"a\nb\n", b"a\r\nb\r\n", "stdout")
-        for actual in [b"a\nb", b"a \nb\n", b"A\nb\n", b"a\n\nb\n"]:
-            with self.assertRaises(Failure):
-                compare(b"a\nb\n", actual, "stdout")
-
-    def test_exit_and_stderr(self):
-        for code, stderr in [(1, b""), (-11, b""), (0, b"unexpected")]:
-            with self.assertRaises(Failure):
-                check_result(subprocess.CompletedProcess([], code, b"ok\n", stderr), b"ok\n")
-
-    def test_reason_and_location_must_share_a_diagnostic(self):
-        expected = [{"reason": "Expected ':'", "line": 3}]
-        check_diagnostics(subprocess.CompletedProcess([], 1, b"",
-            b"error: Expected ':' at line 3\ncompilation terminated.\n"), expected)
-        for diagnostic in [b"error: Expected ':' at line 4", b"error: Expected ':'",
-                           b"error: Expected ':' at line 30\nerror: unrelated at line 3"]:
-            with self.assertRaises(Failure):
-                check_diagnostics(subprocess.CompletedProcess([], 1, b"",
-                    diagnostic + b"\ncompilation terminated.\n"), expected)
-
-    def test_timeout_is_failure_and_saved(self):
-        with tempfile.TemporaryDirectory() as temporary:
-            directory = Path(temporary)
-            with self.assertRaisesRegex(Failure, "timed out"):
-                Commands(directory).run([sys.executable, "-c", "import time; time.sleep(5)"],
-                                        directory, timeout=0.05)
-            self.assertIn('"timeout_expired": true', (directory / "01.json").read_text())
-
-
-if __name__ == "__main__":
-    unittest.main()