tests/unit/test_strncpy.c: Test STRNCPY()

Signed-off-by: Alejandro Colomar <alx@kernel.org>

tests/unit/Makefile.am

@@ -4,6 +4,7 @@ if HAVE_CMOCKA
 TESTS = $(check_PROGRAMS)
 
 check_PROGRAMS = \
+    test_strncpy \
     test_strtcpy \
     test_xasprintf
 
@@ -32,6 +33,18 @@ test_logind_LDADD = \
     $(LIBSYSTEMD) \
     $(NULL)
 
+test_strncpy_SOURCES = \
+    test_strncpy.c \
+    $(NULL)
+test_strncpy_CFLAGS = \
+    $(AM_FLAGS) \
+    $(NULL)
+test_strncpy_LDFLAGS = \
+    $(NULL)
+test_strncpy_LDADD = \
+    $(CMOCKA_LIBS) \
+    $(NULL)
+
 test_strtcpy_SOURCES = \
     ../../lib/strtcpy.c \
     test_strtcpy.c \

tests/unit/test_strncpy.c

@@ -0,0 +1,85 @@
+/*
+ * SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+
+#include <config.h>
+
+#include <string.h>
+
+#include <stdarg.h>  // Required by <cmocka.h>
+#include <stddef.h>  // Required by <cmocka.h>
+#include <setjmp.h>  // Required by <cmocka.h>
+#include <stdint.h>  // Required by <cmocka.h>
+#include <cmocka.h>
+
+#include "sizeof.h"
+#include "strncpy.h"
+
+
+static void test_STRNCPY_trunc(void **state);
+static void test_STRNCPY_fit(void **state);
+static void test_STRNCPY_pad(void **state);
+
+
+int
+main(void)
+{
+    const struct CMUnitTest  tests[] = {
+        cmocka_unit_test(test_STRNCPY_trunc),
+        cmocka_unit_test(test_STRNCPY_fit),
+        cmocka_unit_test(test_STRNCPY_pad),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}
+
+
+static void
+test_STRNCPY_trunc(void **state)
+{
+	char  buf[3];
+
+	char  src1[4] = {'f', 'o', 'o', 'o'};
+	char  res1[3] = {'f', 'o', 'o'};
+	assert_true(memcmp(res1, STRNCPY(buf, src1), sizeof(buf)) == 0);
+
+	char  src2[5] = "barb";
+	char  res2[3] = {'b', 'a', 'r'};
+	assert_true(memcmp(res2, STRNCPY(buf, src2), sizeof(buf)) == 0);
+}
+
+
+static void
+test_STRNCPY_fit(void **state)
+{
+	char  buf[3];
+
+	char  src1[3] = {'b', 'a', 'z'};
+	char  res1[3] = {'b', 'a', 'z'};
+	assert_true(memcmp(res1, STRNCPY(buf, src1), sizeof(buf)) == 0);
+
+	char  src2[4] = "qwe";
+	char  res2[3] = {'q', 'w', 'e'};
+	assert_true(memcmp(res2, STRNCPY(buf, src2), sizeof(buf)) == 0);
+}
+
+
+static void
+test_STRNCPY_pad(void **state)
+{
+	char  buf[3];
+
+	char  src1[3] = "as";
+	char  res1[3] = {'a', 's', 0};
+	assert_true(memcmp(res1, STRNCPY(buf, src1), sizeof(buf)) == 0);
+
+	char  src2[3] = "";
+	char  res2[3] = {0, 0, 0};
+	assert_true(memcmp(res2, STRNCPY(buf, src2), sizeof(buf)) == 0);
+
+	char  src3[3] = {'a', 0, 'b'};
+	char  res3[3] = {'a', 0, 0};
+	assert_true(memcmp(res3, STRNCPY(buf, src3), sizeof(buf)) == 0);
+}