1 files changed, 66 insertions, 0 deletions
diff --git a/tests/unit/test_sprintf.c b/tests/unit/test_sprintf.c
new file mode 100644
index 0000000..bedcff6
--- /dev/null
+++ b/tests/unit/test_sprintf.c
@@ -0,0 +1,66 @@
+// SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include <stdio.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 "string/sprintf.h"
+
+
+static void test_SNPRINTF_trunc(void **state);
+static void test_SNPRINTF_ok(void **state);
+
+
+int
+main(void)
+{
+    const struct CMUnitTest  tests[] = {
+        cmocka_unit_test(test_SNPRINTF_trunc),
+        cmocka_unit_test(test_SNPRINTF_ok),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}
+
+
+static void
+test_SNPRINTF_trunc(void **state)
+{
+	char  buf[NITEMS("foo")];
+
+	// Test that we're not returning SIZE_MAX
+	assert_true(SNPRINTF(buf, "f%su", "oo") < 0);
+	assert_true(strcmp(buf, "foo") == 0);
+
+	assert_true(SNPRINTF(buf, "barbaz") == -1);
+	assert_true(strcmp(buf, "bar") == 0);
+}
+
+
+static void
+test_SNPRINTF_ok(void **state)
+{
+	char  buf[NITEMS("foo")];
+
+	assert_true(SNPRINTF(buf, "%s", "foo") == strlen("foo"));
+	assert_true(strcmp(buf, "foo") == 0);
+
+	assert_true(SNPRINTF(buf, "%do", 1) == strlen("1o"));
+	assert_true(strcmp(buf, "1o") == 0);
+
+	assert_true(SNPRINTF(buf, "f") == strlen("f"));
+	assert_true(strcmp(buf, "f") == 0);
+
+	assert_true(SNPRINTF(buf, "") == strlen(""));
+	assert_true(strcmp(buf, "") == 0);
+}