tests: Add tests to improve coverage of objarray.c.

tests/basics/memoryview1.py

@@ -28,6 +28,7 @@ print(list(m[1:-1]))
 # this tests get_buffer of memoryview
 m = memoryview(bytearray(2))
 print(bytearray(m))
+print(list(memoryview(memoryview(b'1234')))) # read-only memoryview
 
 import array
 a = array.array('i', [1, 2, 3, 4])
@@ -78,3 +79,9 @@ try:
     m4[1:3] = m2[1:3]
 except ValueError:
     print("ValueError")
+
+# invalid assignment on RHS
+try:
+    memoryview(array.array('i'))[0:2] = b'1234'
+except ValueError:
+    print('ValueError')

tests/misc/non_compliant.py

@@ -118,3 +118,9 @@ print(ustruct.pack('bb', 1, 2, 3))
 
 # struct pack with too few args, not checked by uPy
 print(ustruct.pack('bb', 1))
+
+# array slice assignment with unsupported RHS
+try:
+    bytearray(4)[0:1] = [1, 2]
+except NotImplementedError:
+    print('NotImplementedError')

tests/misc/non_compliant.py.exp

@@ -18,3 +18,4 @@ NotImplementedError
 NotImplementedError
 b'\x01\x02'
 b'\x01\x00'
+NotImplementedError