context could be useful in a callback, now we can retrieve context in a function (be careful to infinite loop)

test/test_option_calculation.py

@@ -44,6 +44,13 @@ def return_calc(i, j, k):
     return i + j + k
 
 
+def is_config(config, **kwargs):
+    if isinstance(config, Config):
+        return 'yes'
+    else:
+        return 'no'
+
+
 def make_description():
     gcoption = ChoiceOption('name', 'GC name', ('ref', 'framework'), 'ref')
     gcdummy = BoolOption('dummy', 'dummy', default=False)
@@ -254,6 +261,29 @@ def test_callback_invalid():
     raises(ValueError, "StrOption('val2', '', callback=return_value, callback_params={'': 'string'})")
     raises(ValueError, "StrOption('val4', '', callback=return_value, callback_params={'value': (('string', False),)})")
     raises(ValueError, "StrOption('val4', '', callback=return_value, callback_params={'value': ((val1, 'string'),)})")
+    raises(ValueError, "StrOption('val4', '', callback=return_value, callback_params={'value': ((val1, False, 'unknown'),)})")
+    raises(ValueError, "StrOption('val4', '', callback=return_value, callback_params={'value': ((val1,),)})")
+
+
+def test_callback_with_context():
+    val1 = StrOption("val1", "", callback=is_config, callback_params={'': ((None,),), 'value': ('string',)})
+    maconfig = OptionDescription('rootconfig', '', [val1])
+    cfg = Config(maconfig)
+    assert cfg.val1 == 'yes'
+
+
+def test_callback_with_context_named():
+    val1 = StrOption("val1", "", callback=is_config, callback_params={'config': ((None,),)})
+    maconfig = OptionDescription('rootconfig', '', [val1])
+    cfg = Config(maconfig)
+    assert cfg.val1 == 'yes'
+
+
+def test_callback_with_error():
+    val1 = StrOption("val1", "", callback=is_config, callback_params={'': ('string',), 'value': ('string',)})
+    maconfig = OptionDescription('rootconfig', '', [val1])
+    cfg = Config(maconfig)
+    assert cfg.val1 == 'no'
 
 
 def test_callback_value():