array_shift et al. have side effects

Closes phpstan/phpstan#8084

Author: ondrejmirtes

bin/functionMetadata_original.php

@@ -31,11 +31,14 @@
 	'array_merge' => ['hasSideEffects' => false],
 	'array_merge_recursive' => ['hasSideEffects' => false],
 	'array_pad' => ['hasSideEffects' => false],
+	'array_pop' => ['hasSideEffects' => true],
 	'array_product' => ['hasSideEffects' => false],
+	'array_push' => ['hasSideEffects' => true],
 	'array_rand' => ['hasSideEffects' => false],
 	'array_replace' => ['hasSideEffects' => false],
 	'array_replace_recursive' => ['hasSideEffects' => false],
 	'array_reverse' => ['hasSideEffects' => false],
+	'array_shift' => ['hasSideEffects' => true],
 	'array_slice' => ['hasSideEffects' => false],
 	'array_sum' => ['hasSideEffects' => false],
 	'array_udiff' => ['hasSideEffects' => false],
@@ -45,6 +48,7 @@
 	'array_uintersect_assoc' => ['hasSideEffects' => false],
 	'array_uintersect_uassoc' => ['hasSideEffects' => false],
 	'array_unique' => ['hasSideEffects' => false],
+	'array_unshift' => ['hasSideEffects' => true],
 	'array_values' => ['hasSideEffects' => false],
 	'asin' => ['hasSideEffects' => false],
 	'asinh' => ['hasSideEffects' => false],

resources/functionMetadata.php

@@ -696,12 +696,15 @@
 	'array_merge' => ['hasSideEffects' => false],
 	'array_merge_recursive' => ['hasSideEffects' => false],
 	'array_pad' => ['hasSideEffects' => false],
+	'array_pop' => ['hasSideEffects' => true],
 	'array_product' => ['hasSideEffects' => false],
+	'array_push' => ['hasSideEffects' => true],
 	'array_rand' => ['hasSideEffects' => false],
 	'array_replace' => ['hasSideEffects' => false],
 	'array_replace_recursive' => ['hasSideEffects' => false],
 	'array_reverse' => ['hasSideEffects' => false],
 	'array_search' => ['hasSideEffects' => false],
+	'array_shift' => ['hasSideEffects' => true],
 	'array_slice' => ['hasSideEffects' => false],
 	'array_sum' => ['hasSideEffects' => false],
 	'array_udiff' => ['hasSideEffects' => false],
@@ -711,6 +714,7 @@
 	'array_uintersect_assoc' => ['hasSideEffects' => false],
 	'array_uintersect_uassoc' => ['hasSideEffects' => false],
 	'array_unique' => ['hasSideEffects' => false],
+	'array_unshift' => ['hasSideEffects' => true],
 	'array_values' => ['hasSideEffects' => false],
 	'asin' => ['hasSideEffects' => false],
 	'asinh' => ['hasSideEffects' => false],

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1171,6 +1171,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8635.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8625.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8621.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8084.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-8084.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Bug8084b;
+
+use Exception;
+use function array_shift;
+use function PHPStan\Testing\assertType;
+
+class Bug8084
+{
+	/**
+	 * @param array{a: 0, b?: 1} $arr
+	 * @throws Exception
+	 */
+	public function run(array $arr): void
+	{
+		assertType('0', array_shift($arr) ?? throw new Exception());
+		assertType('1|null', array_shift($arr));
+	}
+}

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -360,4 +360,12 @@ public function testBug7968(): void
 		$this->analyse([__DIR__ . '/data/bug-7968.php'], []);
 	}
 
+	public function testBug8084(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->strictUnnecessaryNullsafePropertyFetch = true;
+
+		$this->analyse([__DIR__ . '/data/bug-8084.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-8084.php

@@ -0,0 +1,19 @@
+<?php // lint >= 8.0
+
+namespace Bug8084a;
+
+use Exception;
+use function array_shift;
+use function PHPStan\Testing\assertType;
+
+class Bug8084
+{
+	/**
+	 * @param string[] $params
+	 */
+	public function run(array $params): void
+	{
+		$a = array_shift($params) ?? throw new Exception();
+		$b = array_shift($params) ?? "default_b";
+	}
+}