Post review fixes for test_json_parser test module

. Add missing copytight notices
. improve code coverage
. put work files in a temp directory in the standard location
. improve error checking in C code
. indent perl files with perltidy
. add some comments

per comments from Michael Paquier

Discussion: https://postgr.es/m/ZiC3-cdFys4-6xSk@paquier.xyz

4 files changed, 106 insertions, 35 deletions

diff --git a/src/test/modules/test_json_parser/t/001_test_json_parser_incremental.pl b/src/test/modules/test_json_parser/t/001_test_json_parser_incremental.pl
index 24f665c0218..30506be0339 100644
--- a/src/test/modules/test_json_parser/t/001_test_json_parser_incremental.pl
+++ b/src/test/modules/test_json_parser/t/001_test_json_parser_incremental.pl
@@ -1,4 +1,9 @@
 
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+# Test the incremental (table-driven) json parser.
+
+
 use strict;
 use warnings;
 
@@ -6,15 +11,19 @@ use PostgreSQL::Test::Utils;
 use Test::More;
 use FindBin;
 
-use File::Temp qw(tempfile);
-
 my $test_file = "$FindBin::RealBin/../tiny.json";
 
 my $exe = "test_json_parser_incremental";
 
+# Test the  usage error
+my ($stdout, $stderr) = run_command([ $exe, "-c", 10 ]);
+like($stderr, qr/Usage:/, 'error message if not enough arguments');
+
+# Test that we get success for small chunk sizes from 64 down to 1.
+
 for (my $size = 64; $size > 0; $size--)
 {
-	my ($stdout, $stderr) = run_command( [$exe, "-c", $size, $test_file] );
+	($stdout, $stderr) = run_command([ $exe, "-c", $size, $test_file ]);
 
 	like($stdout, qr/SUCCESS/, "chunk size $size: test succeeds");
 	is($stderr, "", "chunk size $size: no error output");
diff --git a/src/test/modules/test_json_parser/t/002_inline.pl b/src/test/modules/test_json_parser/t/002_inline.pl
index e63d36a6a87..b95cb6b16a9 100644
--- a/src/test/modules/test_json_parser/t/002_inline.pl
+++ b/src/test/modules/test_json_parser/t/002_inline.pl
@@ -1,3 +1,9 @@
+
+# Copyright (c) 2021-2024, PostgreSQL Global Development Group
+
+# Test success or failure of the incremental (table-driven) JSON parser
+# for a variety of small inputs.
+
 use strict;
 use warnings;
 
@@ -6,6 +12,8 @@ use Test::More;
 
 use File::Temp qw(tempfile);
 
+my $dir = PostgreSQL::Test::Utils::tempdir;
+
 sub test
 {
 	local $Test::Builder::Level = $Test::Builder::Level + 1;
@@ -14,27 +22,32 @@ sub test
 	my $exe = "test_json_parser_incremental";
 	my $chunk = length($json);
 
+	# Test the input with chunk sizes from max(input_size, 64) down to 1
+
 	if ($chunk > 64)
 	{
 		$chunk = 64;
 	}
 
-	my ($fh, $fname) = tempfile(UNLINK => 1);
+	my ($fh, $fname) = tempfile(DIR => $dir);
 	print $fh "$json";
 	close($fh);
 
-	foreach my $size (reverse(1..$chunk))
+	foreach my $size (reverse(1 .. $chunk))
 	{
-		my ($stdout, $stderr) = run_command( [$exe, "-c", $size, $fname] );
+		my ($stdout, $stderr) = run_command([ $exe, "-c", $size, $fname ]);
 
 		if (defined($params{error}))
 		{
-			unlike($stdout, qr/SUCCESS/, "$name, chunk size $size: test fails");
-			like($stderr, $params{error}, "$name, chunk size $size: correct error output");
+			unlike($stdout, qr/SUCCESS/,
+				"$name, chunk size $size: test fails");
+			like($stderr, $params{error},
+				"$name, chunk size $size: correct error output");
 		}
 		else
 		{
-			like($stdout, qr/SUCCESS/, "$name, chunk size $size: test succeeds");
+			like($stdout, qr/SUCCESS/,
+				"$name, chunk size $size: test succeeds");
 			is($stderr, "", "$name, chunk size $size: no error output");
 		}
 	}
@@ -58,26 +71,60 @@ test("serial escapes", '"\\\\\\\\\\\\\\\\"');
 test("interrupted escapes", '"\\\\\\"\\\\\\\\\\"\\\\"');
 test("whitespace", '     ""     ');
 
-test("unclosed empty object", "{", error => qr/input string ended unexpectedly/);
+test("unclosed empty object",
+	"{", error => qr/input string ended unexpectedly/);
 test("bad key", "{{", error => qr/Expected string or "}", but found "\{"/);
 test("bad key", "{{}", error => qr/Expected string or "}", but found "\{"/);
-test("numeric key", "{1234: 2}", error => qr/Expected string or "}", but found "1234"/);
-test("second numeric key", '{"a": "a", 1234: 2}', error => qr/Expected string, but found "1234"/);
-test("unclosed object with pair", '{"key": "value"', error => qr/input string ended unexpectedly/);
-test("missing key value", '{"key": }', error => qr/Expected JSON value, but found "}"/);
-test("missing colon", '{"key" 12345}', error => qr/Expected ":", but found "12345"/);
-test("missing comma", '{"key": 12345 12345}', error => qr/Expected "," or "}", but found "12345"/);
-test("overnested array", "[" x 6401, error => qr/maximum permitted depth is 6400/);
-test("overclosed array", "[]]", error => qr/Expected end of input, but found "]"/);
-test("unexpected token in array", "[ }}} ]", error => qr/Expected array element or "]", but found "}"/);
+test("numeric key", "{1234: 2}",
+	error => qr/Expected string or "}", but found "1234"/);
+test(
+	"second numeric key",
+	'{"a": "a", 1234: 2}',
+	error => qr/Expected string, but found "1234"/);
+test(
+	"unclosed object with pair",
+	'{"key": "value"',
+	error => qr/input string ended unexpectedly/);
+test("missing key value",
+	'{"key": }', error => qr/Expected JSON value, but found "}"/);
+test(
+	"missing colon",
+	'{"key" 12345}',
+	error => qr/Expected ":", but found "12345"/);
+test(
+	"missing comma",
+	'{"key": 12345 12345}',
+	error => qr/Expected "," or "}", but found "12345"/);
+test("overnested array",
+	"[" x 6401, error => qr/maximum permitted depth is 6400/);
+test("overclosed array",
+	"[]]", error => qr/Expected end of input, but found "]"/);
+test("unexpected token in array",
+	"[ }}} ]", error => qr/Expected array element or "]", but found "}"/);
 test("junk punctuation", "[ ||| ]", error => qr/Token "|" is invalid/);
-test("missing comma in array", "[123 123]", error => qr/Expected "," or "]", but found "123"/);
+test("missing comma in array",
+	"[123 123]", error => qr/Expected "," or "]", but found "123"/);
 test("misspelled boolean", "tru", error => qr/Token "tru" is invalid/);
-test("misspelled boolean in array", "[tru]", error => qr/Token "tru" is invalid/);
-test("smashed top-level scalar", "12zz", error => qr/Token "12zz" is invalid/);
-test("smashed scalar in array", "[12zz]", error => qr/Token "12zz" is invalid/);
-test("unknown escape sequence", '"hello\vworld"', error => qr/Escape sequence "\\v" is invalid/);
-test("unescaped control", "\"hello\tworld\"", error => qr/Character with value 0x09 must be escaped/);
-test("incorrect escape count", '"\\\\\\\\\\\\\\"', error => qr/Token ""\\\\\\\\\\\\\\"" is invalid/);
+test(
+	"misspelled boolean in array",
+	"[tru]",
+	error => qr/Token "tru" is invalid/);
+test("smashed top-level scalar", "12zz",
+	error => qr/Token "12zz" is invalid/);
+test(
+	"smashed scalar in array",
+	"[12zz]",
+	error => qr/Token "12zz" is invalid/);
+test(
+	"unknown escape sequence",
+	'"hello\vworld"',
+	error => qr/Escape sequence "\\v" is invalid/);
+test("unescaped control",
+	"\"hello\tworld\"",
+	error => qr/Character with value 0x09 must be escaped/);
+test(
+	"incorrect escape count",
+	'"\\\\\\\\\\\\\\"',
+	error => qr/Token ""\\\\\\\\\\\\\\"" is invalid/);
 
 done_testing();
diff --git a/src/test/modules/test_json_parser/t/003_test_semantic.pl b/src/test/modules/test_json_parser/t/003_test_semantic.pl
index 7b4941b7f9f..7d3e07e750c 100644
--- a/src/test/modules/test_json_parser/t/003_test_semantic.pl
+++ b/src/test/modules/test_json_parser/t/003_test_semantic.pl
@@ -1,3 +1,9 @@
+
+# Copyright (c) 2021-2024, PostgreSQL Global Development Group
+
+# Test the incremental JSON parser with semantic routines, and compare the
+# output with the expected output.
+
 use strict;
 use warnings;
 
@@ -12,17 +18,18 @@ my $test_out = "$FindBin::RealBin/../tiny.out";
 
 my $exe = "test_json_parser_incremental";
 
-my ($stdout, $stderr) = run_command( [$exe, "-s", $test_file] );
+my ($stdout, $stderr) = run_command([ $exe, "-s", $test_file ]);
 
 is($stderr, "", "no error output");
 
-my ($fh, $fname) = tempfile();
+my $dir = PostgreSQL::Test::Utils::tempdir;
+my ($fh, $fname) = tempfile(DIR => $dir);
 
-print $fh $stdout,"\n";
+print $fh $stdout, "\n";
 
 close($fh);
 
-($stdout, $stderr) = run_command(["diff", "-u", $fname, $test_out]);
+($stdout, $stderr) = run_command([ "diff", "-u", $fname, $test_out ]);
 
 is($stdout, "", "no output diff");
 is($stderr, "", "no diff error");
diff --git a/src/test/modules/test_json_parser/t/004_test_parser_perf.pl b/src/test/modules/test_json_parser/t/004_test_parser_perf.pl
index ec322c13912..c61fdf898a9 100644
--- a/src/test/modules/test_json_parser/t/004_test_parser_perf.pl
+++ b/src/test/modules/test_json_parser/t/004_test_parser_perf.pl
@@ -1,4 +1,11 @@
 
+# Copyright (c) 2021-2024, PostgreSQL Global Development Group
+
+# Test the JSON parser performance tester. Here we are just checking that
+# the performance tester can run, both with the standard parser and the
+# incremental parser. An actual performance test will run with thousands
+# of iterations onstead of just one.
+
 use strict;
 use warnings;
 
@@ -14,21 +21,22 @@ my $exe = "test_json_parser_perf";
 
 my $contents = slurp_file($test_file);
 
-my ($fh, $fname) = tempfile(UNLINK => 1);
+my $dir = PostgreSQL::Test::Utils::tempdir;
+my ($fh, $fname) = tempfile(DIR => $dir);
 
 # repeat the input json file 50 times in an array
 
-print $fh, '[', $contents , ",$contents" x 49 , ']';
+print $fh, '[', $contents, ",$contents" x 49, ']';
 
 close($fh);
 
 # but only do one iteration
 
-my ($result) = run_log([ $exe, "1",  $fname ] );
+my ($result) = run_log([ $exe, "1", $fname ]);
 
-ok($result == 0, "perf test runs with RD parser");
+ok($result == 0, "perf test runs with recursive descent parser");
 
-$result = run_log([ $exe, "-i" , "1",  $fname ]);
+$result = run_log([ $exe, "-i", "1", $fname ]);
 
 ok($result == 0, "perf test runs with table driven parser");