Improve mbedtls_test_err_add_check documentation
Improve and clarify error messages and comments when checking error codes.
Signed-off-by: Chris Jones <christopher.jones@arm.com>
diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index a26f1ee..9bfe085 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -280,9 +280,15 @@
#if defined(MBEDTLS_TEST_HOOKS)
/**
- * \brief Check that a pure high-level error code is being combined with a
- * pure low-level error code as otherwise the resultant error code
+ * \brief Check that only a pure high-level error code is being combined with
+ * a pure low-level error code as otherwise the resultant error code
* would be corrupted.
+ *
+ * \note Both high-level and low-level error codes cannot be greater than
+ * zero however can be zero. If one error code is zero then the
+ * other error code is returned even if both codes are zero.
+ *
+ * \note If the check fails, fail the test currently being run.
*/
void mbedtls_test_err_add_check( int high, int low,
const char *file, int line);