Fix array_filter with callback that always evaluates to false

phpstan · Jan 24, 2022 · d8dc6d0 · d8dc6d0
1 parent 156700b
commit d8dc6d0
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Showing 5 changed files with 125 additions and 0 deletions.
diff --git a/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php b/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php
@@ -83,6 +83,9 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 					$scope = $scope->assignVariable($itemVariableName, $itemType);
 					$scope = $scope->filterByTruthyValue($expr);
 					$itemType = $scope->getVariableType($itemVariableName);
+					if ($itemType instanceof NeverType) {
+						return new ConstantArrayType([], []);
+					}
 				}
 			}
 

diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -275,6 +275,13 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/infer-array-key.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/offset-value-after-assign.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2112.php');
+
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-filter.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-filter-callables.php');
+		if (PHP_VERSION_ID >= 70400) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/data/array-filter-arrow-functions.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-flip.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-map.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-map-closure.php');

diff --git a/tests/PHPStan/Analyser/data/array-filter-arrow-functions.php b/tests/PHPStan/Analyser/data/array-filter-arrow-functions.php
@@ -0,0 +1,39 @@
+<?php // lint >= 7.4
+
+namespace ArrayFilter;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param int[] $list1
+ * @param int[] $list2
+ * @param int[] $list3
+ */
+function alwaysEvaluatesToFalse(array $list1, array $list2, array $list3): void
+{
+	$filtered1 = array_filter($list1, static fn($item): bool => is_string($item));
+	assertType('array{}', $filtered1);
+
+	$filtered2 = array_filter($list2, static fn($item): bool => is_string($item), ARRAY_FILTER_USE_KEY);
+	assertType('array<int>', $filtered2); // not supported yet
+
+	$filtered3 = array_filter($list3, static fn($item, $key): bool => is_string($item) && is_string($key), ARRAY_FILTER_USE_BOTH);
+	assertType('array<int>', $filtered3); // not supported yet
+}
+
+/**
+ * @param array<int|string, int|string> $map1
+ * @param array<int|string, int|string> $map2
+ * @param array<int|string, int|string> $map3
+ */
+function filtersString(array $map1, array $map2, array $map3, array $map4): void
+{
+	$filtered1 = array_filter($map1, static fn($item): bool => is_string($item));
+	assertType('array<int|string, string>', $filtered1);
+
+	$filtered2 = array_filter($map2, static fn($item): bool => is_string($item), ARRAY_FILTER_USE_KEY);
+	assertType('array<int|string, int|string>', $filtered2); // not supported yet
+
+	$filtered3 = array_filter($map3, static fn($item, $key): bool => is_string($item) && is_string($key), ARRAY_FILTER_USE_BOTH);
+	assertType('array<int|string, int|string>', $filtered3); // not supported yet
+}
diff --git a/tests/PHPStan/Analyser/data/array-filter-callables.php b/tests/PHPStan/Analyser/data/array-filter-callables.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace ArrayFilter;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param int[] $list1
+ * @param int[] $list2
+ * @param int[] $list3
+ */
+function alwaysEvaluatesToFalse(array $list1, array $list2, array $list3): void
+{
+	$filtered1 = array_filter($list1, static function ($item): bool { return is_string($item); });
+	assertType('array{}', $filtered1);
+
+	$filtered2 = array_filter($list2, static function ($item): bool { return is_string($item); }, ARRAY_FILTER_USE_KEY);
+	assertType('array<int>', $filtered2); // not supported yet
+
+	$filtered3 = array_filter($list3, static function ($item, $key): bool { return is_string($item) && is_string($key); }, ARRAY_FILTER_USE_BOTH);
+	assertType('array<int>', $filtered3); // not supported yet
+}
+
+/**
+ * @param array<int|string, int|string> $map1
+ * @param array<int|string, int|string> $map2
+ * @param array<int|string, int|string> $map3
+ */
+function filtersString(array $map1, array $map2, array $map3): void
+{
+	$filtered1 = array_filter($map1, static function ($item): bool { return is_string($item); });
+	assertType('array<int|string, string>', $filtered1);
+
+	$filtered2 = array_filter($map2, static function ($item): bool { return is_string($item); }, ARRAY_FILTER_USE_KEY);
+	assertType('array<int|string, int|string>', $filtered2); // not supported yet
+
+	$filtered3 = array_filter($map3, static function ($item, $key): bool { return is_string($item) && is_string($key); }, ARRAY_FILTER_USE_BOTH);
+	assertType('array<int|string, int|string>', $filtered3); // not supported yet
+}
diff --git a/tests/PHPStan/Analyser/data/array-filter.php b/tests/PHPStan/Analyser/data/array-filter.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace ArrayFilter;
+
+use function PHPStan\Testing\assertType;
+
+function withoutAnyArgs(): void
+{
+	$filtered1 = array_filter();
+	assertType('array', $filtered1);
+}
+
+/**
+ * @param $var1 $mixed
+ */
+function withMixedInsteadOfArray($var1): void
+{
+	$filtered1 = array_filter($var1);
+	assertType('(array|null)', $filtered1);
+}
+
+/**
+ * @param array<string, bool|float|int|string> $map1
+ * @param array<string, bool|float|int|string> $map2
+ * @param array<string, bool|float|int|string> $map3
+ */
+function withoutCallback(array $map1, array $map2, array $map3): void
+{
+	$filtered1 = array_filter($map1);
+	assertType('array<string, float|int<min, -1>|int<1, max>|non-empty-string|true>', $filtered1);
+
+	$filtered2 = array_filter($map2, null, ARRAY_FILTER_USE_KEY);
+	assertType('array<string, bool|float|int|string>', $filtered2); // not supported yet
+
+	$filtered3 = array_filter($map3, null, ARRAY_FILTER_USE_BOTH);
+	assertType('array<string, bool|float|int|string>', $filtered3); // not supported yet
+}