tests/extmod/vfs_mountinfo.py: Add test for no-args mount output.

Signed-off-by: Anson Mansfield <amansfield@mantaro.com>

tests/extmod/vfs_mountinfo.py

@@ -0,0 +1,66 @@
+# test VFS functionality without any particular filesystem type
+
+try:
+    import os, vfs
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+import errno
+
+
+class Filesystem:
+    def __init__(self, id, paths=[]):
+        self.id = id
+        self.paths = paths
+
+    def mount(self, readonly, mksfs):
+        print("mount", self)
+
+    def umount(self):
+        print("umount", self)
+
+    def stat(self, path):
+        if path in self.paths:
+            return (0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+        else:
+            raise OSError
+
+    statvfs = stat
+
+    def open(self, path, mode):
+        pass
+
+    def __repr__(self):
+        return "Filesystem(%d)" % self.id
+
+
+# first we umount any existing mount points the target may have
+try:
+    vfs.umount("/")
+except OSError:
+    pass
+for path in os.listdir("/"):
+    vfs.umount("/" + path)
+
+
+print(vfs.mount())
+
+vfs.mount(Filesystem(1), "/foo")
+
+print(vfs.mount())
+
+vfs.mount(Filesystem(2), "/bar/baz")
+
+print(vfs.mount())
+
+vfs.mount(Filesystem(3), "/bar")
+
+print(vfs.mount())
+
+vfs.umount("/bar/baz")
+
+print(vfs.mount())
+
+vfs.mount(Filesystem(4), "/")
+
+print(vfs.mount())

tests/extmod/vfs_mountinfo.py.exp

@@ -0,0 +1,11 @@
+[]
+mount Filesystem(1)
+[(Filesystem(1), '/foo')]
+mount Filesystem(2)
+[(Filesystem(1), '/foo'), (Filesystem(2), '/bar/baz')]
+mount Filesystem(3)
+[(Filesystem(1), '/foo'), (Filesystem(2), '/bar/baz'), (Filesystem(3), '/bar')]
+umount Filesystem(2)
+[(Filesystem(1), '/foo'), (Filesystem(3), '/bar')]
+mount Filesystem(4)
+[(Filesystem(1), '/foo'), (Filesystem(3), '/bar'), (Filesystem(4), '/')]