When inside isset, array fetch can return null

This prevents false positive for various types of issues inside empty, such as RedundantConditionGivenDocblockType and TypeDoesNotContainType.
vimeo · Feb 28, 2024 · c1b1b7a · c1b1b7a
1 parent 9aa450b
commit c1b1b7a
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Showing 5 changed files with 24 additions and 2 deletions.
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
@@ -171,7 +171,7 @@ public static function analyze(
 
         $codebase = $statements_analyzer->getCodebase();
 
-        if ($keyed_array_var_id
+        if ($keyed_array_var_id !== null
             && $context->hasVariable($keyed_array_var_id)
             && !$context->vars_in_scope[$keyed_array_var_id]->possibly_undefined
             && $stmt_var_type
@@ -250,6 +250,10 @@ public static function analyze(
                 }
             }
 
+            if ($context->inside_isset && !$stmt_type->hasMixed()) {
+                $stmt_type = Type::combineUnionTypes($stmt_type, Type::getNull());
+            }
+
             $statements_analyzer->node_data->setType($stmt, $stmt_type);
 
             if ($context->inside_isset
@@ -304,7 +308,7 @@ public static function analyze(
             }
         }
 
-        if ($keyed_array_var_id
+        if ($keyed_array_var_id !== null
             && $context->hasVariable($keyed_array_var_id)
             && (!($stmt_type = $statements_analyzer->node_data->getType($stmt)) || $stmt_type->isVanillaMixed())
         ) {

diff --git a/tests/ArrayAssignmentTest.php b/tests/ArrayAssignmentTest.php
@@ -1234,6 +1234,8 @@ function takesList(array $arr) : void {
                             foreach ($arr[0] as $k => $v) {}
                         }
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'nonEmptyAssignmentToListElement' => [
                 'code' => '<?php

diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
@@ -2602,6 +2602,7 @@ function($val) { return (int)$val; },
                 'assertions' => [
                     '$line===' => 'array{0: int, ...<array-key, int>}',
                 ],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'arrayUnshiftOnEmptyArrayMeansNonEmptyList' => [
                 'code' => '<?php

diff --git a/tests/TypeReconciliation/EmptyTest.php b/tests/TypeReconciliation/EmptyTest.php
@@ -231,6 +231,8 @@ function _processScopes($scopes) : void {
                     function foo(array $o) : void {
                         if (empty($o[0]) && empty($o[1])) {}
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'multipleEmptiesInConditionWithMixedOffset' => [
                 'code' => '<?php
@@ -315,6 +317,8 @@ function baz(array $data) : void {
                             if (empty($data[Foo::ONE])) {}
                         }
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'doubleEmptyCheckTwoArrays' => [
                 'code' => '<?php
@@ -330,6 +334,8 @@ function foo(array $a, array $b) : void {
                     function foo(array $arr) : void {
                         if (empty($arr["a"]) && empty($arr["b"])) {}
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'doubleEmptyCheckOnTKeyedArrayVariableOffsets' => [
                 'code' => '<?php
@@ -340,6 +346,8 @@ function foo(int $i, int $j) : void {
 
                         if (empty($arr[$i]) && empty($arr[$j])) {}
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'checkArrayEmptyUnknownRoot' => [
                 'code' => '<?php
@@ -626,6 +634,11 @@ function test(string $s): void {
                     '$x===' => 'true',
                 ],
             ],
+            'emptyArrayFetch' => [
+                'code' => '<?php
+                    /** @var array<true> $a */
+                    if (empty($a["a"])) {}',
+            ],
         ];
     }
 

diff --git a/tests/TypeReconciliation/RedundantConditionTest.php b/tests/TypeReconciliation/RedundantConditionTest.php
@@ -575,6 +575,8 @@ function foo(array $a) : void {
                             if (empty($a["foo"])) {}
                         }
                     }',
+                'assertions' => [],
+                'ignored_issues' => ['RiskyTruthyFalsyComparison'],
             ],
             'suppressRedundantConditionAfterAssertNonEmpty' => [
                 'code' => '<?php