py/objslice: Ensure slice is not hashable.

As per https://bugs.python.org/issue408326, the slice object should not be
hashable.  Since MicroPython has an implicit fallback when the unary_op
slot is empty, we need to fill this slot.

Signed-off-by: David Lechner <david@pybricks.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/basics/slice_op.py b/tests/basics/slice_op.py
new file mode 100644
index 000000000..f1e83c5e2
--- /dev/null
+++ b/tests/basics/slice_op.py
@@ -0,0 +1,15 @@
+
+try:
+    t = [][:]
+except:
+    print("SKIP")
+    raise SystemExit
+
+
+# REVISIT: slice comparison operators are not implemented in MicroPython
+
+# test that slice is not hashable, i.e. it can't be used to copy a dict
+try:
+    {}[:] = {}
+except TypeError:
+    print('TypeError')