Improve some psql test code

Split psql_like() into two functions psql_like() and psql_fails_like()
and make them mirror the existing command_like() and
command_fails_like() more closely.  In particular, follow the
universal convention that the test name is the last argument.

Discussion: https://www.postgresql.org/message-id/3199e176-424e-1bef-f180-c1548466c2da@enterprisedb.com

src/bin/psql/t/001_basic.pl

@@ -12,40 +12,36 @@ program_help_ok('psql');
 program_version_ok('psql');
 program_options_handling_ok('psql');
 
-my ($stdout, $stderr);
-my $result;
-
-# Execute a psql command and check its result patterns.
+# Execute a psql command and check its output.
 sub psql_like
 {
 	local $Test::Builder::Level = $Test::Builder::Level + 1;
 
-	my $node            = shift;
-	my $test_name       = shift;
-	my $query           = shift;
-	my $expected_stdout = shift;
-	my $expected_stderr = shift;
+	my ($node, $sql, $expected_stdout, $test_name) = @_;
+
+	my ($ret, $stdout, $stderr) = $node->psql('postgres', $sql);
+
+	is($ret,    0,  "$test_name: exit code 0");
+	is($stderr, '', "$test_name: no stderr");
+	like($stdout, $expected_stdout, "$test_name: matches");
+
+	return;
+}
+
+# Execute a psql command and check that it fails and check the stderr.
+sub psql_fails_like
+{
+	local $Test::Builder::Level = $Test::Builder::Level + 1;
 
-	die "cannot specify both expected stdout and stderr here"
-	  if (defined($expected_stdout) && defined($expected_stderr));
+	my ($node, $sql, $expected_stderr, $test_name) = @_;
 
 	# Use the context of a WAL sender, some of the tests rely on that.
 	my ($ret, $stdout, $stderr) = $node->psql(
-		'postgres', $query,
-		on_error_die => 0,
+		'postgres', $sql,
 		replication  => 'database');
 
-	if (defined($expected_stdout))
-	{
-		is($ret,    0,  "$test_name: expected result code");
-		is($stderr, '', "$test_name: no stderr");
-		like($stdout, $expected_stdout, "$test_name: stdout matches");
-	}
-	if (defined($expected_stderr))
-	{
-		isnt($ret, 0, "$test_name: expected result code");
-		like($stderr, $expected_stderr, "$test_name: stderr matches");
-	}
+	isnt($ret, 0, "$test_name: exit code not 0");
+	like($stderr, $expected_stderr, "$test_name: matches");
 
 	return;
 }
@@ -53,6 +49,9 @@ sub psql_like
 # test --help=foo, analogous to program_help_ok()
 foreach my $arg (qw(commands variables))
 {
+	my ($stdout, $stderr);
+	my $result;
+
 	$result = IPC::Run::run [ 'psql', "--help=$arg" ], '>', \$stdout, '2>',
 	  \$stderr;
 	ok($result, "psql --help=$arg exit code 0");
@@ -70,15 +69,15 @@ max_wal_senders = 4
 });
 $node->start;
 
-psql_like($node, '\copyright', '\copyright', qr/Copyright/, undef);
-psql_like($node, '\help without arguments', '\help', qr/ALTER/, undef);
-psql_like($node, '\help with argument', '\help SELECT', qr/SELECT/, undef);
+psql_like($node, '\copyright', qr/Copyright/, '\copyright');
+psql_like($node, '\help', qr/ALTER/, '\help without arguments');
+psql_like($node, '\help SELECT', qr/SELECT/, '\help with argument');
 
 # Test clean handling of unsupported replication command responses
-psql_like(
+psql_fails_like(
 	$node,
-	'handling of unexpected PQresultStatus',
 	'START_REPLICATION 0/0',
-	undef, qr/unexpected PQresultStatus: 8$/);
+	qr/unexpected PQresultStatus: 8$/,
+	'handling of unexpected PQresultStatus');
 
 done_testing();