t/unit-tests: convert ctype tests to use clar

Convert the ctype tests to use the new clar unit testing framework.
Introduce a new function `cl_failf()` that allows us to print a
formatted error message, which we can use to point out which of the
characters was classified incorrectly. This results in output like this
on failure:

    # start of suite 1: ctype
    not ok 1 - ctype::isspace
        ---
        reason: |
          Test failed.
          0x0d is classified incorrectly: expected 0, got 1
        at:
          file: 't/unit-tests/ctype.c'
          line: 36
          function: 'test_ctype__isspace'
        ---
    ok 2 - ctype::isdigit
    ok 3 - ctype::isalpha
    ok 4 - ctype::isalnum
    ok 5 - ctype::is_glob_special
    ok 6 - ctype::is_regex_special
    ok 7 - ctype::is_pathspec_magic
    ok 8 - ctype::isascii
    ok 9 - ctype::islower
    ok 10 - ctype::isupper
    ok 11 - ctype::iscntrl
    ok 12 - ctype::ispunct
    ok 13 - ctype::isxdigit
    ok 14 - ctype::isprint

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 68 insertions, 10 deletions

diff --git a/t/unit-tests/t-ctype.c b/t/unit-tests/ctype.c
index e28a7f50f9..32e65867cd 100644
--- a/t/unit-tests/t-ctype.c
+++ b/t/unit-tests/ctype.c
@@ -1,16 +1,16 @@
-#include "test-lib.h"
+#include "unit-test.h"
 
 #define TEST_CHAR_CLASS(class, string) do { \
 	size_t len = ARRAY_SIZE(string) - 1 + \
 		BUILD_ASSERT_OR_ZERO(ARRAY_SIZE(string) > 0) + \
 		BUILD_ASSERT_OR_ZERO(sizeof(string[0]) == sizeof(char)); \
-	if_test (#class " works") { \
-		for (int i = 0; i < 256; i++) { \
-			if (!check_int(class(i), ==, !!memchr(string, i, len)))\
-				test_msg("      i: 0x%02x", i); \
-		} \
-		check(!class(EOF)); \
+	for (int i = 0; i < 256; i++) { \
+		int actual = class(i), expect = !!memchr(string, i, len); \
+		if (actual != expect) \
+			cl_failf("0x%02x is classified incorrectly: expected %d, got %d", \
+				 i, expect, actual); \
 	} \
+	cl_assert(!class(EOF)); \
 } while (0)
 
 #define DIGIT "0123456789"
@@ -31,21 +31,72 @@
 	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
 	"\x7f"
 
-int cmd_main(int argc, const char **argv) {
+void test_ctype__isspace(void)
+{
 	TEST_CHAR_CLASS(isspace, " \n\r\t");
+}
+
+void test_ctype__isdigit(void)
+{
 	TEST_CHAR_CLASS(isdigit, DIGIT);
+}
+
+void test_ctype__isalpha(void)
+{
 	TEST_CHAR_CLASS(isalpha, LOWER UPPER);
+}
+
+void test_ctype__isalnum(void)
+{
 	TEST_CHAR_CLASS(isalnum, LOWER UPPER DIGIT);
+}
+
+void test_ctype__is_glob_special(void)
+{
 	TEST_CHAR_CLASS(is_glob_special, "*?[\\");
+}
+
+void test_ctype__is_regex_special(void)
+{
 	TEST_CHAR_CLASS(is_regex_special, "$()*+.?[\\^{|");
+}
+
+void test_ctype__is_pathspec_magic(void)
+{
 	TEST_CHAR_CLASS(is_pathspec_magic, "!\"#%&',-/:;<=>@_`~");
+}
+
+void test_ctype__isascii(void)
+{
 	TEST_CHAR_CLASS(isascii, ASCII);
+}
+
+void test_ctype__islower(void)
+{
 	TEST_CHAR_CLASS(islower, LOWER);
+}
+
+void test_ctype__isupper(void)
+{
 	TEST_CHAR_CLASS(isupper, UPPER);
+}
+
+void test_ctype__iscntrl(void)
+{
 	TEST_CHAR_CLASS(iscntrl, CNTRL);
+}
+
+void test_ctype__ispunct(void)
+{
 	TEST_CHAR_CLASS(ispunct, PUNCT);
+}
+
+void test_ctype__isxdigit(void)
+{
 	TEST_CHAR_CLASS(isxdigit, DIGIT "abcdefABCDEF");
-	TEST_CHAR_CLASS(isprint, LOWER UPPER DIGIT PUNCT " ");
+}
 
-	return test_done();
+void test_ctype__isprint(void)
+{
+	TEST_CHAR_CLASS(isprint, LOWER UPPER DIGIT PUNCT " ");
 }
diff --git a/t/unit-tests/unit-test.h b/t/unit-tests/unit-test.h
index 66ec2387cc..85e5d6a948 100644
--- a/t/unit-tests/unit-test.h
+++ b/t/unit-tests/unit-test.h
@@ -1,3 +1,10 @@
 #include "git-compat-util.h"
 #include "clar/clar.h"
 #include "clar-decls.h"
+#include "strbuf.h"
+
+#define cl_failf(fmt, ...) do { \
+	char desc[4096]; \
+	snprintf(desc, sizeof(desc), fmt, __VA_ARGS__); \
+	clar__fail(__FILE__, __func__, __LINE__, "Test failed.", desc, 1); \
+} while (0)