tests: add small values test for xtimer_usleep

tests/xtimer_usleep_short/Makefile

@@ -0,0 +1,8 @@
+include ../Makefile.tests_common
+
+USEMODULE += xtimer
+
+include $(RIOTBASE)/Makefile.include
+
+test:
+	./tests/01-run.py

tests/xtimer_usleep_short/main.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2017 HAW-Hamburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     tests
+ * @{
+ *
+ * @file
+ * @brief       xtimer_usleep_short test application
+ *
+ * @author      Michel Rottleuthner <michel.rottleuthner@haw-hamburg.de>
+ * @}
+ */
+#include <stdio.h>
+#include "xtimer.h"
+
+#define TEST_USLEEP_MIN (0)
+#define TEST_USLEEP_MAX (500)
+
+int main(void)
+{
+    xtimer_sleep(3);
+    printf("This test will call xtimer_usleep for values from %d down to %d\n",
+            TEST_USLEEP_MAX, TEST_USLEEP_MIN);
+
+    for (int i = TEST_USLEEP_MAX; i >= TEST_USLEEP_MIN; i--) {
+        printf("going to sleep %d usecs...\n", i);
+        xtimer_usleep(i);
+    }
+
+    puts("Test end.");
+
+    return 0;
+}

tests/xtimer_usleep_short/tests/01-run.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+
+# Copyright (C) 2017 Michel Rottleuthner <michel.rottleuthner@haw-hamburg.de>
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+import os
+import sys
+import pexpect
+
+sys.path.append(os.path.join(os.environ['RIOTBASE'], 'dist/tools/testrunner'))
+import testrunner
+
+def testfunc(child):
+
+    child.expect(u"This test will call xtimer_usleep for values from \\d+ down to \\d+\r\n")
+
+    i = 500
+
+    while (i >= 0):
+        try:
+            child.expect(u"going to sleep \\d+ usecs...\r\n", timeout=3)
+        except pexpect.TIMEOUT:
+            print("xtimer stuck when trying to sleep %d usecs" % (i+1));
+            print("[FAILED]")
+            break;
+        i = i -1
+
+    child.expect(u"Test end.", timeout=3)
+
+if __name__ == "__main__":
+    sys.exit(testrunner.run(testfunc))