Error when a class member is redefined #6686
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Note that your fix broke a whole bunch of new analyzer tests. |
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Fixed. |
| @@ -2563,6 +2563,9 @@ def analyze_member_lvalue(self, lval: MemberExpr, explicit_type: bool, is_final: | |||
| if cur_node and is_final: | |||
| # Overrides will be checked in type checker. | |||
| self.fail("Cannot redefine an existing name as final", lval) | |||
| if (not lval.node and cur_node and isinstance(cur_node.node, Var) and | |||
| cur_node.node.is_inferred and explicit_type): | |||
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TBH I don't follow the logic here, maybe add a comment explaining this?
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Yes, I can write a comment. But before, let me explain: Fail if passing first time, the node exists and it's a Var node, it's type is inferred, and new assignment has an explicit type.
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Basically yes. But please try to avoid this:
x += 1 # Increment x
Describe the intent and how the code achieves it.
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@onlined Are you going to add this comment (also in the old analyzer)?
test-data/unit/check-classes.test
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| class C: | ||
| def __init__(self) -> None: | ||
| self.foo = 12 | ||
| self.foo: int = 12 # E: Name 'self.foo' already defined on line 3 |
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Could you please also add a test for something like this:
class C:
foo = 12
def __init__(self) -> None:
self.foo: int = 12 # E: Attribute 'foo' already defined on line 2
mypy/semanal.py
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| @@ -2288,6 +2288,9 @@ def analyze_member_lvalue(self, lval: MemberExpr, explicit_type: bool, is_final: | |||
| if cur_node and is_final: | |||
| # Overrides will be checked in type checker. | |||
| self.fail("Cannot redefine an existing name as final", lval) | |||
| if (cur_node and isinstance(cur_node.node, Var) and cur_node.node.is_inferred and | |||
| explicit_type): | |||
| self.name_already_defined('self.' + lval.name, lval, cur_node) | |||
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I wouldn't use this error message because self.foo is not a name, it is an attribute. I would better use Attribute "foo" already defined ....
mypy/newsemanal/semanal.py
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| @@ -2563,6 +2563,9 @@ def analyze_member_lvalue(self, lval: MemberExpr, explicit_type: bool, is_final: | |||
| if cur_node and is_final: | |||
| # Overrides will be checked in type checker. | |||
| self.fail("Cannot redefine an existing name as final", lval) | |||
| if (not lval.node and cur_node and isinstance(cur_node.node, Var) and | |||
| cur_node.node.is_inferred and explicit_type): | |||
| self.name_already_defined('self.' + lval.name, lval, cur_node) | |||
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Using this in the new analyzer is dangerous, it not not only shows the error, but also has some special code for deferring unknown names.
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I couldn't understand what you meant. Could you explain it a little more?
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I actually confused with with name_not_defined(). This one is OK. Anyway, did you check that in the situation where an error is emitted, no new variable created, and the l.h.s. points to an existing one?
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Yes, basically if cur_node is not None, l.h.s. points to an existing variable.
test-data/unit/check-newsemanal.test
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| def __init__(self) -> None: | ||
| self.foo = 12 | ||
| self.foo: int = 12 # E: Name 'self.foo' already defined on line 3 | ||
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I am not very sure about this. Should I really add same tests to new semantic analyzer tests?
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You don't need to duplicate tests, most test are currently run with both analyzers.
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Removed redundant tests.
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Thanks for updates! I left few more comments. |
| @@ -2563,6 +2563,9 @@ def analyze_member_lvalue(self, lval: MemberExpr, explicit_type: bool, is_final: | |||
| if cur_node and is_final: | |||
| # Overrides will be checked in type checker. | |||
| self.fail("Cannot redefine an existing name as final", lval) | |||
| if (not lval.node and cur_node and isinstance(cur_node.node, Var) and | |||
| cur_node.node.is_inferred and explicit_type): | |||
There was a problem hiding this comment.
@onlined Are you going to add this comment (also in the old analyzer)?
Fixes #6571.