Index: uspace/lib/c/test/str.c
===================================================================
--- uspace/lib/c/test/str.c	(revision 3bacee1839e6f355100ab4ea86bb211e9ecf19ed)
+++ uspace/lib/c/test/str.c	(revision 6abff2a8b48b577b0150c419532e65aeff614f3b)
@@ -88,4 +88,33 @@
 }
 
+PCUT_TEST(str_str_found)
+{
+	const char *hs = "abracadabra";
+	const char *n = "raca";
+	char *p;
+
+	p = str_str(hs, n);
+	PCUT_ASSERT_TRUE((const char *)p == hs + 2);
+}
+
+PCUT_TEST(str_str_not_found)
+{
+	const char *hs = "abracadabra";
+	const char *n = "racab";
+	char *p;
+
+	p = str_str(hs, n);
+	PCUT_ASSERT_TRUE(p == NULL);
+}
+
+PCUT_TEST(str_str_empty_n)
+{
+	const char *hs = "abracadabra";
+	const char *n = "";
+	char *p;
+
+	p = str_str(hs, n);
+	PCUT_ASSERT_TRUE((const char *)p == hs);
+}
 
 PCUT_EXPORT(str);