Project tagged-union narrowings through OR and foreach destructure#5531
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`if (A || B)` truthy where `A` and `B` are booleans backed by stored conditional-expression holders (e.g. `$isA = $obj instanceof ClassA; $isB = $obj instanceof ClassB;`) needs to apply the held narrowings of the *target* (`$obj`) to the OR-truthy scope as the union of the per-arm narrowings. specifyTypesInCondition for each arm only sees the boolean variable itself, so the `$obj` narrowing was invisible until a later inner check pinned one of the booleans down. For each conditional-holder target we now resolve its type in the left-truthy and right-truthy filtered scopes, and when both narrow it strictly below the original we add a sure type carrying the union to the OR-truthy result. Gated to keep certainty unchanged: only project when the target stays Yes-defined in all three scopes — `if (empty($a['bar']))` for instance must leave `$a` Maybe-defined because `empty()` tolerates undefined offsets. Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
`foreach ($a as [$x, $y, …])` over an iterable whose value type is a
tagged union of constant arrays (e.g. `array<array{null, int}|array{int,
null}>`) loses the per-variant link between the destructured variables:
each one ends up as the position's union (`int|null`) and `if ($x ===
null)` doesn't narrow `$y` even though every variant pairs the two.
Recover the link in `enterForeach` by registering conditional-expression
holders on each destructured variable: for every variant, "when this
variable matches the variant's value at its position, the *other*
variables match the variant's values at their positions". A later
narrowing on any one of them then fires the matching holder and pins the
others to the corresponding variant's values.
Handles flat positional and string-/int-keyed `List_` patterns where
each item targets a plain Variable; nested destructure falls back to the
existing per-variable type tracking. The held conditions integrate with
the existing reassignment invalidation, so `$x = null;` inside the body
severs the binding for `$x` only.
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
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Summary
Two related precision improvements that build on the existing
conditional-expression-holder machinery. They share a worktree but are
independent — the second commit doesn't depend on the first.
1. Project stored-boolean narrowings through
||truthyif (A || B)truthy whereAandBare stored booleans(
\$isA = \$obj instanceof ClassA;/\$isB = \$obj instanceof ClassB;)left the held narrowing of
\$objinvisible inside the OR — each arm'sspecifyTypesInConditiononly narrows the boolean variable itself, so\$objstayedmixeduntil a nested check pinned one of the booleansdown.
For each conditional-holder target we now resolve its type in the
left-truthy and right-truthy filtered scopes, and when both narrow it
strictly below the original we add a sure type carrying the union.
Gated so that certainty is preserved (e.g.
if (empty(\$a['bar']))correctly leaves
\$aMaybe-defined).2. Track destructure relationships across tagged-union foreach
foreach (\$a as [\$x, \$y, …])over an iterable whose value type is atagged union of constant arrays —
array<array{null, int}|array{int, null}>,array<array{tag: 'a', data: int}|array{tag: 'b', data: string}>, etc. — used to lose the per-variant link between thedestructured variables: each one became the position-wise union
(`int|null`) and
if (\$x === null)no longer narrowed\$y.In
enterForeachwe now register conditional-expression holders oneach destructured variable: per variant, "when this variable matches
the variant's value at its position, the other variables match the
variant's values at their positions". A later narrowing fires the
matching holder. Handles flat positional and string/int-keyed
List_patterns; nested destructure falls back to per-variable tracking. The
holders integrate with the existing reassignment invalidation, so
\$x = null;inside the body severs the binding for\$xonly.Test plan
or-of-stored-booleans-narrowing.phpcovers two-/three-wayinstanceof OR, plus a mixed-narrowing-kind variant where only one
arm narrows each target.
foreach-destructure-tagged-union.phpcovers two- andthree-variant unions with positional, named-key (
'tag'/'data'), and constant-int discriminators, plus a single-variantno-op case and a reassignment-invalidation case.
tests/PHPStan/Analyser/NodeScopeResolverTest.php: 1542/1542.tests/PHPStan/Analyser/+tests/PHPStan/Rules/+tests/PHPStan/Type/: 8231 tests, 59 pre-existing skips, 0 failures.make phpstan: green.additive.
🤖 Generated with Claude Code
Closes phpstan/phpstan#9519