def test_trace(self):
v = Variable(self.root)
vname = str(v)
trace = []
def read_tracer(*args):
trace.append(('read', ) + args)
def write_tracer(*args):
trace.append(('write', ) + args)
cb1 = v.trace_variable('r', read_tracer)
cb2 = v.trace_variable('wu', write_tracer)
self.assertEqual(sorted(v.trace_vinfo()), [('r', cb1), ('wu', cb2)])
self.assertEqual(trace, [])
v.set('spam')
self.assertEqual(trace, [('write', vname, '', 'w')])
trace = []
v.get()
self.assertEqual(trace, [('read', vname, '', 'r')])
trace = []
info = sorted(v.trace_vinfo())
v.trace_vdelete('w', cb1) # Wrong mode
self.assertEqual(sorted(v.trace_vinfo()), info)
with self.assertRaises(TclError):
v.trace_vdelete('r', 'spam') # Wrong command name
self.assertEqual(sorted(v.trace_vinfo()), info)
v.trace_vdelete('r', (cb1, 43)) # Wrong arguments
self.assertEqual(sorted(v.trace_vinfo()), info)
v.get()
self.assertEqual(trace, [('read', vname, '', 'r')])
trace = []
v.trace_vdelete('r', cb1)
self.assertEqual(v.trace_vinfo(), [('wu', cb2)])
v.get()
self.assertEqual(trace, [])
trace = []
del write_tracer
gc_collect()
v.set('eggs')
self.assertEqual(trace, [('write', vname, '', 'w')])
