def test_init_invalid_type(self):
"""Test symbol lookup when type cannot be found
There was a read/write check that verifies the plc_typ was not None,
but this was removed.
"""
var = PLCVariable(name="UnknownType",
ads_type=0,
symbol_type="non_existent_type")
var.index_group = 123
var.index_offset = 100
var.plc_type = constants.PLCTYPE_BYTE # Set to something real
self.handler.add_variable(var)
with self.plc:
# Create symbol while providing everything:
symbol = AdsSymbol(self.plc, name=var.name)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertIsNone(symbol.plc_type)
# with self.assertRaises(ValueError) as cm:
# # Without type specified, it cannot read
# symbol.read()
# self.assertIn('Cannot read or write', str(cm.exception))
with self.assertRaises(TypeError) as cm:
# Error is thrown inside pyads_ex
symbol.read()
self.assertIn("NoneType", str(cm.exception))
self.assertAdsRequestsCount(1) # Only a WRITE followed by a READ
def test_init_by_name_matrix_style(self):
"""Test symbol creation when it's an array denoted as matrix
This is how an array originating from Simulink could look like.
"""
var = PLCVariable(
"ArrayVar",
ads_type=0,
symbol_type="matrix_21_int8_T", # Simulink array looks like this
)
var.plc_type = constants.PLCTYPE_ARR_SINT(21) # Have to do this
# manually
var.index_group = 123
var.index_offset = 100
self.handler.add_variable(var)
self.plc.open()
symbol = AdsSymbol(
self.plc,
name=var.name,
index_group=var.index_group,
index_offset=var.index_offset,
symbol_type=var.symbol_type,
) # No lookup
# Verify looked up info
self.assertEqual(var.plc_type, symbol.plc_type)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertAdsRequestsCount(0) # No requests