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fix null coalesce false positive for multi-dimensional array in loop #4475

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Merged
merged 2 commits into from
Oct 24, 2025
+75 −3
Merged

fix null coalesce false positive for multi-dimensional array in loop #4475

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3372181
fix null coalesce false positive for multi-dimensional array in loop
schlndh Oct 24, 2025
50cbd45
add NSRT test
schlndh Oct 24, 2025
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24 changes: 22 additions & 2 deletions src/Type/ArrayType.php
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Original file line number Diff line number Diff line change
Expand Up @@ -375,13 +375,33 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $uni
public function setExistingOffsetValueType(Type $offsetType, Type $valueType): Type
{
if ($this->itemType->isConstantArray()->yes() && $valueType->isConstantArray()->yes()) {
$newItemType = $this->itemType;
$newItemTypes = [];

foreach ($valueType->getConstantArrays() as $constArray) {
foreach ($constArray->getKeyTypes() as $keyType) {
$newItemType = $this->itemType;
$optionalKeyTypes = [];
foreach ($constArray->getKeyTypes() as $i => $keyType) {
$newItemType = $newItemType->setExistingOffsetValueType($keyType, $constArray->getOffsetValueType($keyType));

if (!$constArray->isOptionalKey($i)) {
continue;
}

$optionalKeyTypes[] = $keyType;
}
$newItemTypes[] = $newItemType;

if ($optionalKeyTypes === []) {
continue;
}

foreach ($optionalKeyTypes as $keyType) {
$newItemType = $newItemType->unsetOffset($keyType);
}
$newItemTypes[] = $newItemType;
}

$newItemType = TypeCombinator::union(...$newItemTypes);
if ($newItemType !== $this->itemType) {
return new self(
$this->keyType,
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2 changes: 1 addition & 1 deletion tests/PHPStan/Analyser/AnalyserIntegrationTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -983,7 +983,7 @@ public function testBug7581(): void
public function testBug7903(): void
{
$errors = $this->runAnalyse(__DIR__ . '/data/bug-7903.php');
$this->assertCount(23, $errors);
$this->assertCount(24, $errors);
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I'm ignoring this change. This test was added as a performance regression test (I'm not sure if/how that works, or why it makes assertions about the errors in the first place) and it's extremely hard to reason about the code. So I'm assuming that the reported errors don't matter.

Fundamentally, the array handling in PHPStan has a set of bugs and as a result of this PR it will have a slightly different (hopefully smaller) set of bugs. But there can definitely be cases where the new code causes a regression.

If you want to see the difference detected in the test for yourself here are the errors:

Previous:

115: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: 0, ssss: 0, ssss_next: 0}|array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: float}|array{oooo_rrrrr: float}.
125: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
130: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
135: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
169: Offset 'ccccc_rrrrr' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
170: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr?: float, ccccc_rrrrr: float}.
174: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr?: float, ccccc_rrrrr: float}.
178: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float, ccccc_rrrrr: float}.
182: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0|float, oooo_rrrrr: 0, oooo_yyyy: 0|float, ssss: 0, ssss_next: 0}|array{oooo_yyyy: float}.
184: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0|float, oooo_rrrrr: 0, oooo_yyyy: 0|float, ssss: 0, ssss_next: 0}|array{oooo_yyyy: float}.
194: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
195: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0|float, oooo_rrrrr: 0, oooo_yyyy: 0|float, ssss: 0, ssss_next: 0}|array{oooo_yyyy: float}.
198: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
199: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
203: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
207: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
208: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0|float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{oooo_rrrrr: float}.
212: Comparison operation ">" between 0 and 0 is always false.
213: Comparison operation ">" between 0 and 0 is always false.
214: Comparison operation ">" between 0 and 0 is always false.
215: Comparison operation ">" between 0 and 0 is always false.
229: Comparison operation ">" between 0 and 0 is always false.
230: Comparison operation ">" between 0 and 0 is always false.

New:

115: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: 0, ssss: 0, ssss_next: 0}|array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: float}|array{oooo_rrrrr: float}.
116: Offset 'ssss' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: float, ssss: 0, ssss_next: 0}|array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: float}|array{oooo_rrrrr: float, oooo_yyyy: float}.
117: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next: 0|float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss: float, ssss_next?: float}.
125: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy?: 0|float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss?: float, ssss_next?: float}.
126: Offset 'ssss' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy: float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss?: float, ssss_next?: float}.
127: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy?: 0|float, ssss: float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss: float, ssss_next?: float}.
130: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy?: 0|float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss?: float, ssss_next?: float}.
131: Offset 'ssss' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy: float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss?: float, ssss_next?: float}.
132: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy?: 0|float, ssss: float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss: float, ssss_next?: float}.
135: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: float, oooo_yyyy?: 0|float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss?: float, ssss_next?: float}.
136: Offset 'ssss' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy: float, ssss?: 0|float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy: float, ssss?: float, ssss_next?: float}.
137: Offset 'ssss_next' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0, oooo_rrrrr: 0|float, oooo_yyyy?: 0|float, ssss: float, ssss_next?: 0|float}|array{oooo_rrrrr: float, oooo_yyyy?: float, ssss: float, ssss_next?: float}.
170: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy?: 0|float, oooo_rrrrr?: 0|float, oooo_yyyy?: 0|float, ssss?: 0|float, ssss_next?: 0|float}.
172: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy?: float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{ccccc_rrrrr: float, ccccc_yyyy?: float}.
174: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy?: 0|float, oooo_rrrrr?: 0|float, oooo_yyyy?: 0|float, ssss?: 0|float, ssss_next?: 0|float}.
176: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{ccccc_rrrrr: float}.
178: Offset 'ccccc_yyyy' might not exist on array{ccccc_rrrrr: float, ccccc_yyyy: 0|float, oooo_rrrrr: 0|float, oooo_yyyy: 0|float, ssss: 0|float, ssss_next: 0|float}|array{ccccc_rrrrr: float}.
200: Offset 'oooo_yyyy' might not exist on array{ccccc_rrrrr: 0, ccccc_yyyy: 0|float, oooo_rrrrr: 0, oooo_yyyy?: 0|float, ssss: 0, ssss_next: 0}|non-empty-array{oooo_yyyy?: float, ccccc_yyyy?: float}.
212: Comparison operation ">" between 0 and 0 is always false.
213: Comparison operation ">" between 0 and 0 is always false.
214: Comparison operation ">" between 0 and 0 is always false.
215: Comparison operation ">" between 0 and 0 is always false.
229: Comparison operation ">" between 0 and 0 is always false.
230: Comparison operation ">" between 0 and 0 is always false.

}

public function testBug7901(): void
Expand Down
24 changes: 24 additions & 0 deletions tests/PHPStan/Analyser/nsrt/bug-optionalArrayKeyInMultiDimArrayLoop.php
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Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
<?php declare(strict_types = 1);

namespace OptionalArrayKeyInMultiDimArrayLoop;

/**
* @param array<int, array{1: int, 2: int, 3: float}> $rows
*/
function foo(array $rows): mixed
{
$itemMap = [];

foreach ($rows as $row) {
$x = $row[1];
$month = $row[2];

$itemMap[$x][$month]['foo'] ??= 5;
$itemMap[$x][$month]['bar'] ??= 5;

\PHPStan\Testing\assertType('array{foo: 5, bar: 5, amount?: 0.0}', $itemMap[$x][$month]);
$itemMap[$x][$month]['amount'] ??= 0.0;
}

return $itemMap;
}
5 changes: 5 additions & 0 deletions tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
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Expand Up @@ -337,6 +337,11 @@ public function testBug12553(): void
$this->analyse([__DIR__ . '/data/bug-12553.php'], []);
}

public function testBugMultiDimLoop(): void
{
$this->analyse([__DIR__ . '/data/bug-nullCoalesceMultiDimLoop.php'], []);
}

public function testIssetAfterRememberedConstructor(): void
{
$this->analyse([__DIR__ . '/data/isset-after-remembered-constructor.php'], [
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23 changes: 23 additions & 0 deletions tests/PHPStan/Rules/Variables/data/bug-nullCoalesceMultiDimLoop.php
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@@ -0,0 +1,23 @@
<?php declare(strict_types = 1);

namespace BugNullCoalesceMultiDimLoop;

/**
* @param array<int, array{1: int, 2: int, 3: float}> $rows
*/
function foo(array $rows): mixed
{
$itemMap = [];

foreach ($rows as $row) {
$x = $row[1];
$month = $row[2];

$itemMap[$x][$month]['foo'] ??= 5;
$itemMap[$x][$month]['bar'] ??= 5;

$itemMap[$x][$month]['amount'] ??= 0.0;
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The same test in tests/PHPStan/Analyser/nsrt/ with some assertType calls would be nice. Make sure it fails first 😊

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Added and it does fail in 2.1.x: https://phpstan.org/r/b97ea05c-33dc-4287-8223-cd5a6369730d

}

return $itemMap;
}
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