From 13d5f6e6b459b25d4e39555fc539f0845654fc3d Mon Sep 17 00:00:00 2001
From: "Martine S. Lenders" <m.lenders@fu-berlin.de>
Date: Wed, 18 Dec 2019 12:15:33 +0100
Subject: [PATCH] tests: provide test for `vfs`+`fmt` corner-case

On `native` when using `vfs` the `fmt` print functions do not work.
This is because the `fmt` module uses the `write()` system call which
is bend by the `native_vfs` module to use `vfs_write()`. However,
`native` does not use a `stdio` module to print. Instead, it just
writes to the hosts standard I/O directly. As such, STDIN, STDOUT, and
STDERR are never initialized for `vfs` so `vfs` does not recognize
`STDIN_FILENO`, `STDOUT_FILENO` and `STDERR_FILENO` as valid file
descriptors.

This test case showcases this bug.
---
 tests/vfs_plus_stdio/Makefile        |  7 +++++++
 tests/vfs_plus_stdio/main.c          | 27 +++++++++++++++++++++++++++
 tests/vfs_plus_stdio/tests/01-run.py | 18 ++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 tests/vfs_plus_stdio/Makefile
 create mode 100644 tests/vfs_plus_stdio/main.c
 create mode 100755 tests/vfs_plus_stdio/tests/01-run.py

diff --git a/tests/vfs_plus_stdio/Makefile b/tests/vfs_plus_stdio/Makefile
new file mode 100644
index 0000000000..86625c0bea
--- /dev/null
+++ b/tests/vfs_plus_stdio/Makefile
@@ -0,0 +1,7 @@
+DEVELHELP=0
+include ../Makefile.tests_common
+
+USEMODULE += vfs
+USEMODULE += fmt
+
+include $(RIOTBASE)/Makefile.include
diff --git a/tests/vfs_plus_stdio/main.c b/tests/vfs_plus_stdio/main.c
new file mode 100644
index 0000000000..48890c09e8
--- /dev/null
+++ b/tests/vfs_plus_stdio/main.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2019 Freie Universität Berlin
+ *
+ * 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       Tests VFS together with stdio on a board
+ *
+ * @author      Martine S. Lenders <m.lenders@fu-berlin.de>
+ *
+ * @}
+ */
+
+#include "fmt.h"
+
+int main(void)
+{
+    print_str("SUCCESS\n");
+    return 0;
+}
diff --git a/tests/vfs_plus_stdio/tests/01-run.py b/tests/vfs_plus_stdio/tests/01-run.py
new file mode 100755
index 0000000000..d16f4a5268
--- /dev/null
+++ b/tests/vfs_plus_stdio/tests/01-run.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2019 Freie Universität Berlin
+#
+# 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 sys
+from testrunner import run
+
+
+def testfunc(child):
+    child.expect_exact('SUCCESS')
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc, timeout=1))