MutaFix run: boltons-002

tests/test_dictutils.py::test_many_to_many

E   AttributeError: 'list' object has no attribute 'data'

1. boltons/dictutils.py::ManyToMany.remove call depth 1 · Ochiai 1.00 (failing 1, passing 0)
2. boltons/dictutils.py::ManyToMany.update call depth 1 · Ochiai 1.00 (failing 1, passing 0)
3. boltons/dictutils.py::ManyToMany.__delitem__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
4. boltons/dictutils.py::ManyToMany.add call depth 1 · Ochiai 1.00 (failing 1, passing 0)
5. boltons/dictutils.py::ManyToMany.__setitem__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
6. boltons/dictutils.py::ManyToMany.__init__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
7. boltons/dictutils.py::ManyToMany.__getitem__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
8. boltons/dictutils.py::ManyToMany.iteritems call depth 1 · Ochiai 1.00 (failing 1, passing 0)
9. boltons/dictutils.py::ManyToMany.__len__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
10. boltons/dictutils.py::ManyToMany.__contains__ call depth 1 · Ochiai 1.00 (failing 1, passing 0)
11. boltons/dictutils.py::ManyToMany.replace call depth 1 · Ochiai 0.00 (failing 0, passing 0)
12. boltons/dictutils.py::OrderedMultiDict.update call depth 1 · Ochiai 0.00 (failing 0, passing 3)
13. boltons/urlutils.py::OrderedMultiDict.update call depth 1 · Ochiai 0.00 (failing 0, passing 0)
14. boltons/setutils.py::IndexedSet.remove call depth 1 · Ochiai 0.00 (failing 0, passing 0)
15. boltons/fileutils.py::replace call depth 1 · Ochiai 0.00 (failing 0, passing 0)
16. boltons/setutils.py::_ComplementSet.update call depth 1 · Ochiai 0.00 (failing 0, passing 0)
17. boltons/setutils.py::IndexedSet.add call depth 1 · Ochiai 0.00 (failing 0, passing 0)
18. boltons/dictutils.py::ManyToMany.__repr__ call depth 1 · Ochiai 0.00 (failing 0, passing 0)
19. boltons/setutils.py::IndexedSet.update call depth 1 · Ochiai 0.00 (failing 0, passing 0)
20. boltons/dictutils.py::ManyToMany.get call depth 1 · Ochiai 0.00 (failing 0, passing 0)

We need to look deeper. The error occurs during the test. Let's examine the test again:

In test_many_to_many, there is a line:
    del m2m.inv['a']

This invokes __delitem__ on the inv attribute? Actually, m2m.inv is probably another ManyToMany instance? Wait, looking at the class: ManyToMany likely has .data and .inv attributes, both of which are dict-like objects mapping keys to sets of values. The .inv is the inverse mapping.

When we do `del m2m.inv['a']`, that calls __delitem__ on the inv object (which is a ManyToMany? Or maybe it's a dict-like helper?). Actually, from the test, we see that m2m.inv is used like a dict: m2m.inv['a'] returns a frozenset. And we can delete a key from it: del m2m.inv['a'].

So the inv attribute is probably an instance of a class that behaves like a dict mapping values to sets of keys. It might be a ManyToMany itself? Or maybe it's a _InvDict? Let's look at the ManyToMany class definition.

We should read the __init__ and see what self.data and self.inv are.

Let's read candidate 6: ManyToMany.__init__.

But first, let's think: The error says "'list' object has no attribute 'data'". This happens when we try to access .data on something that is a list. Where in the code do we access .data? In the remove method we have self.data[key] and self.inv.data[val]. Also in __delitem__ we have self.data.pop(key) and then self.inv.data[val].remove(key). Also in __setitem__ we have self.data[key] and self.inv.data[val]. Also in add we have self.data[key]

We have seen the __init__ method. It initializes self.data as a dict and self.inv either as another ManyToMany instance (created via self.__class__((_PAIRING, self))) or, in the case of a special tuple, it uses the provided items[1] as self.inv.

Now, note that in the test, we have:
    m2m = ManyToMany()
    ... later ...
    del m2m.inv['a']

This deletion is done on m2m.inv, which is itself a ManyToMany instance (unless we are in the case of the special tuple). The __delitem__ method of ManyToMany is defined (we saw it earlier as candidate [3]):

  951 |     def __delitem__(self, key):
  952 |         for val in self.data.pop(key):
  953 |             self.inv.data[val].remove(key)
  954 |             if not self.inv.data[val]:
  955 |                 del self.inv.data[val]

But wait: when we do `del m2m.inv['a']`, we are calling __delitem__ on the inv ManyToMany instance. Let's look at that again:

In the test:
    m2m = ManyToMany()
    m2m.add(1, 'a')
    m2m.add(1, 'b')
    ... then ...
    del m2m.inv['a']

At this point, m2m.inv is a ManyToMany instance that maps values to keys. Specifically, after adding (1,'a') and (1,'b'), we have:
   m2m.data: {1: {'a','b'}}
   m2m.inv.data: {'a': {1}, 'b': {1}}

Now, when we do `del m2m.inv['a']`, we are invoking the __delitem__ method of the inv ManyToMany instance (which is a ManyToMany) with key='a'.

Let's look at the __delitem__ method again (from candidate [3]):

  951 |     def __delitem__(self, key):
  952 |         for 

We have identified a potential issue in the update method. When the iterable is not of the same type as self (i.e., not a ManyToMany instance), the code assumes that `iterable` has `.data` and `.inv.data` attributes (lines 961, 966). However, in the test, we call `m2m.update([(1, 'a'), (2, 'b')])`, where the argument is a list of tuples. A list does not have a `.data` attribute, so when the code tries to access `other.data` (where `other` is the list), it will raise an AttributeError: 'list' object has no attribute 'data'.

But note: the condition at line 959 is `if type(iterable) is not type(self):`. For a list of tuples, `type(iterable)` is `list`, which is not equal to `type(self)` (which is `ManyToMany`), so we enter this branch. Then we set `other = iterable` (so `other` is the list) and then try to access `other.data` -> error.

However, the test also has a branch for when the iterable has a `keys` method (line 971) and else (line 974) for an iterable of pairs. The list of tuples should be caught by the else branch (line 974) because a list does not have a `keys` method (unless it's a dict, but it's not). So why are we entering the first branch?

Wait: the condition is `if type(iterable) is not type(self):`. This is checking for exact type equality. But note that the test also passes a list to `update` in the line: `m2m.update([(1, 'a'), (2, 'b')])`. This list is not of type `ManyToMany`, so we go into the first branch. But we should go into the else branch (line 974) f

We have identified that the error is: AttributeError: 'list' object has no attribute 'data'
 This happens in the test when calling methods on ManyToMany.

 Let's trace the test step by step until the error.

 The test does:
   m2m = ManyToMany()
   ... (some adds and removes)
   m2m.update([(1, 'a'), (2, 'b')])

 In the update method, when the argument is a list of tuples, it goes to the else branch (line 974-976) because:
   - type(iterable) is list, which is not type(self) (ManyToMany) -> so first condition true? Wait, let's see:

 Actually, the update method has:
   if type(iterable) is not type(self):   # line 959
        ... # This branch is taken for non-ManyToMany iterables
   elif callable(getattr(iterable, 'keys', None)): # line 971
        ... # for dict-like
   else:
        ... # for iterable of pairs (line 974-976)

 So for a list of tuples, it should go to the else branch and call self.add for each pair.

 However, note that the condition at line 959: `if type(iterable) is not type(self):`
   For a list, type(iterable) is list, type(self) is ManyToMany -> they are not the same, so we enter the first branch.

 But wait, the first branch (lines 960-970) assumes that `iterable` has attributes `.data` and `.inv.data`.
   Specifically, it does:
        other = iterable   # line 960
        for k in other.data:   # line 961

 If we pass a list, then `other` is a list, and a list does not have a `.data` attribute -> hence the error.

 Therefore, the bug is in the updat

We have seen the code for ManyToMany. The error is: AttributeError: 'list' object has no attribute 'data'. This happens in the test when doing operations on m2m.inv or m2m.data? Let's trace the test:

The test does:
    m2m = ManyToMany()
    ... 
    m2m.add(1, 'a')
    m2m.add(1, 'b')
    ...
    del m2m.inv['a']   # This is the line that might cause trouble?

Wait, the test does: del m2m.inv['a']

But note: m2m.inv is a ManyToMany instance (the inverse). In the __init__, we see that if items is not provided, then self.inv is set to self.__class__((_PAIRING, self)). So m2m.inv is a ManyToMany that has m2m as its data? Actually, look at line 927: self.inv = self.__class__((_PAIRING, self))

So m2m.inv is a ManyToMany instance that was created with items=(_PAIRING, self). Then in __init__, when items is a tuple and items[0] is _PAIRING, we set self.inv = items[1] (line 924-925). Wait, that's for the inverse? Let's read carefully:

In ManyToMany.__init__:
        if type(items) is tuple and items and items[0] is _PAIRING:
            self.inv = items[1]
        else:
            self.inv = self.__class__((_PAIRING, self))
            if items:
                self.update(items)

So when we create a ManyToMany normally (without the _PAIRING tuple), we go to the else branch and set self.inv to a new ManyToMany created with (_PAIRING, self). That means the inverse's data is set to the original? Actually, note: the inverse is created with items=(_PAIRING, self). Then in its __init

We have examined several methods. The error is: AttributeError: 'list' object has no attribute 'data'
 This suggests that at some point, either self.data or self.inv is a list instead of a dict-like object.

 Let's trace the initialization and updates:

 In __init__:
   self.data = {}   (always a dict)
   if ...:
        self.inv = items[1]   (could be anything? but note: when items is a tuple and items[0] is _PAIRING, then self.inv is set to items[1])
   else:
        self.inv = self.__class__((_PAIRING, self))   (a new ManyToMany)

 So normally, self.inv is a ManyToMany instance, which has a .data attribute (a dict).

 However, note the condition: if type(items) is tuple and items and items[0] is _PAIRING:
   then self.inv = items[1]

 What is _PAIRING? We don't have the context, but it's likely a marker used internally.

 Now, look at the update method:

   if type(iterable) is not type(self):
        other = iterable
        for k in other.data:   # Here, if other is not a ManyToMany, we assume it has a .data attribute?
        ...

 But wait: the condition is: if type(iterable) is not type(self): then we treat it as 'other' and try to access other.data and other.inv.data.

 However, in the test, we call:
        m2m.update([(1, 'a'), (2, 'b')])

 Here, iterable is a list of tuples. So type(iterable) is list, which is not equal to type(self) (ManyToMany). Therefore, we go into the first branch.

 Then we set: other = iterable (the list)

 Then we try to loop: for k in oth