micropython: add micropython component

components/language/micropython/tests/extmod/vfs_userfs.py

@@ -0,0 +1,84 @@
+# test VFS functionality with a user-defined filesystem
+# also tests parts of uio.IOBase implementation
+
+import usys
+
+try:
+    import uio
+
+    uio.IOBase
+    import uos
+
+    uos.mount
+except (ImportError, AttributeError):
+    print("SKIP")
+    raise SystemExit
+
+
+class UserFile(uio.IOBase):
+    def __init__(self, mode, data):
+        assert isinstance(data, bytes)
+        self.is_text = mode.find("b") == -1
+        self.data = data
+        self.pos = 0
+
+    def read(self):
+        if self.is_text:
+            return str(self.data, "utf8")
+        else:
+            return self.data
+
+    def readinto(self, buf):
+        assert not self.is_text
+        n = 0
+        while n < len(buf) and self.pos < len(self.data):
+            buf[n] = self.data[self.pos]
+            n += 1
+            self.pos += 1
+        return n
+
+    def ioctl(self, req, arg):
+        print("ioctl", req, arg)
+        return 0
+
+
+class UserFS:
+    def __init__(self, files):
+        self.files = files
+
+    def mount(self, readonly, mksfs):
+        pass
+
+    def umount(self):
+        pass
+
+    def stat(self, path):
+        print("stat", path)
+        if path in self.files:
+            return (32768, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+        raise OSError
+
+    def open(self, path, mode):
+        print("open", path, mode)
+        return UserFile(mode, self.files[path])
+
+
+# create and mount a user filesystem
+user_files = {
+    "/data.txt": b"some data in a text file",
+    "/usermod1.py": b"print('in usermod1')\nimport usermod2",
+    "/usermod2.py": b"print('in usermod2')",
+}
+uos.mount(UserFS(user_files), "/userfs")
+
+# open and read a file
+f = open("/userfs/data.txt")
+print(f.read())
+
+# import files from the user filesystem
+usys.path.append("/userfs")
+import usermod1
+
+# unmount and undo path addition
+uos.umount("/userfs")
+usys.path.pop()