Commit f5dc1c4
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Expand "invalid hash" test to assert normal StopIteration
Returning an explicit value from a generator function causes that
value to be bound to the `value` attribute of the StopIteration
exception. This is available as the result of "yield from" when it
is used as an expression; or by explicitly catching StopIteration,
binding the StopIteration exception to a variable, and accessing
the attribute. This feature of generators is rarely used.
The `return iter([])` statement in Submodule.iter_items uses this
feature, causing the resulting StopIteration exception object to
have a `value` attribute that refers to a separate second iterator
that also yields no values (#1779).
From context, this behavior is clearly not the goal; a bare return
statement should be used here (which has the same effect except for
the `value` attribute of the StopIteration exception). The code had
used a bare return prior to 82b131c (#1282), when `return` was
changed to `return iter([])`. That was part of a change that added
numerous type annotations. It looks like it was either a mistake,
or possibly an attempt to work around an old bug in a static type
checker.
This commit extends the test_iter_items_from_invalid_hash test to
assert that the `value` attribute of the StopIteration is its usual
default value of None. This commit only extends the test; it does
not fix the bug.1 parent 96fc354 commit f5dc1c4
1 file changed
Lines changed: 2 additions & 1 deletion
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -696,8 +696,9 @@ def test_iter_items_from_nonexistent_hash(self): | |||
| 696 | 696 | def test_iter_items_from_invalid_hash(self): | |
| 697 | 697 | """Check legacy behavaior on BadName (also applies to IOError, i.e. OSError).""" | |
| 698 | 698 | it = Submodule.iter_items(self.rorepo, "xyz") | |
| 699 | - with self.assertRaises(StopIteration): | ||
| 699 | + with self.assertRaises(StopIteration) as ctx: | ||
| 700 | 700 | next(it) | |
| 701 | + self.assertIsNone(ctx.exception.value) | ||
| 701 | 702 | ||
| 702 | 703 | @with_rw_repo(k_no_subm_tag, bare=False) | |
| 703 | 704 | def test_first_submodule(self, rwrepo): | |
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