extmod/vfs_blockdev: Check return type is an integer.

This catches cases where the return type is not a small int, eg it could be
a string, or even a big integer.

Signed-off-by: Damien George <damien@micropython.org>

tests/extmod/vfs_blockdev_invalid.py

@@ -70,8 +70,8 @@ def test(vfs_class):
         try:
             with fs.open("test", "r") as f:
                 print("opened")
-        except OSError as e:
-            print("OSError", e)
+        except Exception as e:
+            print(type(e), e)
 
         # This variant should succeed on open, may fail on read
         # unless the filesystem cached the contents already
@@ -81,8 +81,8 @@ def test(vfs_class):
                 bdev.read_res = res
                 print("read 1", f.read(1))
                 print("read rest", f.read())
-        except OSError as e:
-            print("OSError", e)
+        except Exception as e:
+            print(type(e), e)
 
 
 test(vfs.VfsLfs2)

tests/extmod/vfs_blockdev_invalid.py.exp

@@ -2,27 +2,27 @@
 opened
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-OSError [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-OSError [Errno 22] EINVAL
+<class 'OSError'> [Errno 22] EINVAL
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-OSError [Errno 22] EINVAL
+<class 'OSError'> [Errno 22] EINVAL
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-OSError [Errno 22] EINVAL
+<class 'TypeError'> can't convert str to int
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 <class 'VfsFat'>
 opened
 read 1 a
 read rest aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
-OSError [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'OSError'> [Errno 5] EIO
+<class 'TypeError'> can't convert str to int
+<class 'TypeError'> can't convert str to int