Defer staticmethod/classmethod callable storage to __init__ - #7697

crates/vm/src/builtins/classmethod.rs (1)

92-92: Consider a non-panicking fallback for the __dict__ lookup.

expect("classmethod has __dict__") is currently safe because slot_new always attaches a dict, but it couples init's correctness to that invariant. If a future refactor of slot_new (or a subclass path that constructs via a different code route) ever lands an instance without a dict, this becomes a hard panic in user code.

A small defensive change keeps the happy path identical and falls back gracefully:

♻️ Suggested refactor

-        let dict = zelf.as_object().dict().expect("classmethod has __dict__");
-        for attr in [
-            identifier!(vm.ctx, __doc__),
-            identifier!(vm.ctx, __name__),
-            identifier!(vm.ctx, __qualname__),
-            identifier!(vm.ctx, __module__),
-            identifier!(vm.ctx, __annotations__),
-        ] {
-            if let Ok(value) = callable.get_attr(attr, vm) {
-                dict.set_item(attr, value, vm)?;
-            }
-        }
+        if let Some(dict) = zelf.as_object().dict() {
+            for attr in [
+                identifier!(vm.ctx, __doc__),
+                identifier!(vm.ctx, __name__),
+                identifier!(vm.ctx, __qualname__),
+                identifier!(vm.ctx, __module__),
+                identifier!(vm.ctx, __annotations__),
+            ] {
+                if let Ok(value) = callable.get_attr(attr, vm) {
+                    dict.set_item(attr, value, vm)?;
+                }
+            }
+        }

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@crates/vm/src/builtins/classmethod.rs` at line 92, Replace the panicking
lookup `zelf.as_object().dict().expect("classmethod has __dict__")` with a
non-panicking branch: call `zelf.as_object().dict()` and if it returns
Some(dict) use it, otherwise create a new empty dict (or obtain a canonical
empty/allocated PyDict), attach it to the instance if appropriate, and proceed;
update the code in classmethod handling in classmethod.rs around the
`zelf.as_object().dict()` use so the happy path is unchanged but
missing-__dict__ cases gracefully allocate/attach and avoid panics.