[Outreachy][PATCH v2] Port helper/test-ctype.c to unit-tests/t-ctype.c

[Achu Luma <ach.lumap@gmail.com>]

In the recent codebase update(8bf6fbd00d (Merge branch
'js/doc-unit-tests', 2023-12-09)), a new unit testing framework was
merged, providing a standardized approach for testing C code. Prior to
this update, some unit tests relied on the test helper mechanism,
lacking a dedicated unit testing framework. It's more natural to perform
these unit tests using the new unit test framework.

This commit migrates the unit tests for C character classification
functions (isdigit(), isspace(), etc) from the legacy approach
using the test-tool command `test-tool ctype` in t/helper/test-ctype.c
to the new unit testing framework (t/unit-tests/test-lib.h).

The migration involves refactoring the tests to utilize the testing
macros provided by the framework (TEST() and check_*()).

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Achu Luma <ach.lumap@gmail.com>
---
 In the revised patch, several improvements were made to the 
 TEST_CTYPE_FUNC macro. The updated version enhances error handling 
 by utilizing a direct comparison approach between the func and 
 is_in(string, i) functions across ASCII characters. Additionally, 
 the loop control variable i is locally scoped within the loop, ensuring 
 proper encapsulation. These changes streamline the comparison process 
 and clarify failure reporting. Special thanks to the invaluable reviews 
 by Junio, Phillip and René for their insightful feedback and thorough 
 review of the patch, contributing significantly to these changes.

 Makefile               |  2 +-
 t/helper/test-ctype.c  | 70 --------------------------------------
 t/helper/test-tool.c   |  1 -
 t/helper/test-tool.h   |  1 -
 t/t0070-fundamental.sh |  4 ---
 t/unit-tests/t-ctype.c | 77 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 78 insertions(+), 77 deletions(-)
 delete mode 100644 t/helper/test-ctype.c
 create mode 100644 t/unit-tests/t-ctype.c

diff --git a/Makefile b/Makefile
index 88ba7a3c51..a4df48ba65 100644
--- a/Makefile
+++ b/Makefile
@@ -792,7 +792,6 @@ TEST_BUILTINS_OBJS += test-chmtime.o
 TEST_BUILTINS_OBJS += test-config.o
 TEST_BUILTINS_OBJS += test-crontab.o
 TEST_BUILTINS_OBJS += test-csprng.o
-TEST_BUILTINS_OBJS += test-ctype.o
 TEST_BUILTINS_OBJS += test-date.o
 TEST_BUILTINS_OBJS += test-delta.o
 TEST_BUILTINS_OBJS += test-dir-iterator.o
@@ -1341,6 +1340,7 @@ THIRD_PARTY_SOURCES += sha1dc/%
 
 UNIT_TEST_PROGRAMS += t-basic
 UNIT_TEST_PROGRAMS += t-strbuf
+UNIT_TEST_PROGRAMS += t-ctype
 UNIT_TEST_PROGS = $(patsubst %,$(UNIT_TEST_BIN)/%$X,$(UNIT_TEST_PROGRAMS))
 UNIT_TEST_OBJS = $(patsubst %,$(UNIT_TEST_DIR)/%.o,$(UNIT_TEST_PROGRAMS))
 UNIT_TEST_OBJS += $(UNIT_TEST_DIR)/test-lib.o
diff --git a/t/helper/test-ctype.c b/t/helper/test-ctype.c
deleted file mode 100644
index e5659df40b..0000000000
--- a/t/helper/test-ctype.c
+++ /dev/null
@@ -1,70 +0,0 @@
-#include "test-tool.h"
-
-static int rc;
-
-static void report_error(const char *class, int ch)
-{
-	printf("%s classifies char %d (0x%02x) wrongly\n", class, ch, ch);
-	rc = 1;
-}
-
-static int is_in(const char *s, int ch)
-{
-	/*
-	 * We can't find NUL using strchr. Accept it as the first
-	 * character in the spec -- there are no empty classes.
-	 */
-	if (ch == '\0')
-		return ch == *s;
-	if (*s == '\0')
-		s++;
-	return !!strchr(s, ch);
-}
-
-#define TEST_CLASS(t,s) {			\
-	int i;					\
-	for (i = 0; i < 256; i++) {		\
-		if (is_in(s, i) != t(i))	\
-			report_error(#t, i);	\
-	}					\
-	if (t(EOF))				\
-		report_error(#t, EOF);		\
-}
-
-#define DIGIT "0123456789"
-#define LOWER "abcdefghijklmnopqrstuvwxyz"
-#define UPPER "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-#define PUNCT "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
-#define ASCII \
-	"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" \
-	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
-	"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f" \
-	"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f" \
-	"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f" \
-	"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f" \
-	"\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f" \
-	"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
-#define CNTRL \
-	"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" \
-	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
-	"\x7f"
-
-int cmd__ctype(int argc UNUSED, const char **argv UNUSED)
-{
-	TEST_CLASS(isdigit, DIGIT);
-	TEST_CLASS(isspace, " \n\r\t");
-	TEST_CLASS(isalpha, LOWER UPPER);
-	TEST_CLASS(isalnum, LOWER UPPER DIGIT);
-	TEST_CLASS(is_glob_special, "*?[\\");
-	TEST_CLASS(is_regex_special, "$()*+.?[\\^{|");
-	TEST_CLASS(is_pathspec_magic, "!\"#%&',-/:;<=>@_`~");
-	TEST_CLASS(isascii, ASCII);
-	TEST_CLASS(islower, LOWER);
-	TEST_CLASS(isupper, UPPER);
-	TEST_CLASS(iscntrl, CNTRL);
-	TEST_CLASS(ispunct, PUNCT);
-	TEST_CLASS(isxdigit, DIGIT "abcdefABCDEF");
-	TEST_CLASS(isprint, LOWER UPPER DIGIT PUNCT " ");
-
-	return rc;
-}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 37ba996539..33b9501c21 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -19,7 +19,6 @@ static struct test_cmd cmds[] = {
 	{ "config", cmd__config },
 	{ "crontab", cmd__crontab },
 	{ "csprng", cmd__csprng },
-	{ "ctype", cmd__ctype },
 	{ "date", cmd__date },
 	{ "delta", cmd__delta },
 	{ "dir-iterator", cmd__dir_iterator },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 8a1a7c63da..b72f07ded9 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -12,7 +12,6 @@ int cmd__chmtime(int argc, const char **argv);
 int cmd__config(int argc, const char **argv);
 int cmd__crontab(int argc, const char **argv);
 int cmd__csprng(int argc, const char **argv);
-int cmd__ctype(int argc, const char **argv);
 int cmd__date(int argc, const char **argv);
 int cmd__delta(int argc, const char **argv);
 int cmd__dir_iterator(int argc, const char **argv);
diff --git a/t/t0070-fundamental.sh b/t/t0070-fundamental.sh
index 487bc8d905..a4756fbab9 100755
--- a/t/t0070-fundamental.sh
+++ b/t/t0070-fundamental.sh
@@ -9,10 +9,6 @@ Verify wrappers and compatibility functions.
 TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
-test_expect_success 'character classes (isspace, isalpha etc.)' '
-	test-tool ctype
-'
-
 test_expect_success 'mktemp to nonexistent directory prints filename' '
 	test_must_fail test-tool mktemp doesnotexist/testXXXXXX 2>err &&
 	grep "doesnotexist/test" err
diff --git a/t/unit-tests/t-ctype.c b/t/unit-tests/t-ctype.c
new file mode 100644
index 0000000000..8a215d387a
--- /dev/null
+++ b/t/unit-tests/t-ctype.c
@@ -0,0 +1,77 @@
+#include "test-lib.h"
+
+static int is_in(const char *s, int ch)
+{
+	/*
+	 * We can't find NUL using strchr. Accept it as the first
+	 * character in the spec -- there are no empty classes.
+	 */
+	if (ch == '\0')
+		return ch == *s;
+	if (*s == '\0')
+		s++;
+	return !!strchr(s, ch);
+}
+
+/* Macro to test a character type */
+#define TEST_CTYPE_FUNC(func, string)				\
+static void test_ctype_##func(void)				\
+{								\
+	for (int i = 0; i < 256; i++) {				\
+        	if (!check_int(func(i), ==, is_in(string, i))) 	\
+        		test_msg("       i: %02x", i);		\
+        } 							\
+}
+
+#define DIGIT "0123456789"
+#define LOWER "abcdefghijklmnopqrstuvwxyz"
+#define UPPER "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+#define PUNCT "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
+#define ASCII \
+	"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" \
+	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
+	"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f" \
+	"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f" \
+	"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f" \
+	"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f" \
+	"\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f" \
+	"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
+#define CNTRL \
+	"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" \
+	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
+	"\x7f"
+
+TEST_CTYPE_FUNC(isdigit, DIGIT)
+TEST_CTYPE_FUNC(isspace, " \n\r\t")
+TEST_CTYPE_FUNC(isalpha, LOWER UPPER)
+TEST_CTYPE_FUNC(isalnum, LOWER UPPER DIGIT)
+TEST_CTYPE_FUNC(is_glob_special, "*?[\\")
+TEST_CTYPE_FUNC(is_regex_special, "$()*+.?[\\^{|")
+TEST_CTYPE_FUNC(is_pathspec_magic, "!\"#%&',-/:;<=>@_`~")
+TEST_CTYPE_FUNC(isascii, ASCII)
+TEST_CTYPE_FUNC(islower, LOWER)
+TEST_CTYPE_FUNC(isupper, UPPER)
+TEST_CTYPE_FUNC(iscntrl, CNTRL)
+TEST_CTYPE_FUNC(ispunct, PUNCT)
+TEST_CTYPE_FUNC(isxdigit, DIGIT "abcdefABCDEF")
+TEST_CTYPE_FUNC(isprint, LOWER UPPER DIGIT PUNCT " ")
+
+int cmd_main(int argc, const char **argv) {
+	/* Run all character type tests */
+	TEST(test_ctype_isspace(), "isspace() works as we expect");
+	TEST(test_ctype_isdigit(), "isdigit() works as we expect");
+	TEST(test_ctype_isalpha(), "isalpha() works as we expect");
+	TEST(test_ctype_isalnum(), "isalnum() works as we expect");
+	TEST(test_ctype_is_glob_special(), "is_glob_special() works as we expect");
+	TEST(test_ctype_is_regex_special(), "is_regex_special() works as we expect");
+	TEST(test_ctype_is_pathspec_magic(), "is_pathspec_magic() works as we expect");
+	TEST(test_ctype_isascii(), "isascii() works as we expect");
+	TEST(test_ctype_islower(), "islower() works as we expect");
+	TEST(test_ctype_isupper(), "isupper() works as we expect");
+	TEST(test_ctype_iscntrl(), "iscntrl() works as we expect");
+	TEST(test_ctype_ispunct(), "ispunct() works as we expect");
+	TEST(test_ctype_isxdigit(), "isxdigit() works as we expect");
+	TEST(test_ctype_isprint(), "isprint() works as we expect");
+
+	return test_done();
+}
-- 
2.42.0.windows.2