Fix #3380 - allow comparisons between template param and empty array

vimeo · May 16, 2020 · 4dd0a2b · 4dd0a2b
1 parent f6342a4
commit 4dd0a2b
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Showing 2 changed files with 16 additions and 7 deletions.
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -750,15 +750,11 @@ private static function scrapeEqualityAssertions(
                 && ($var_type = $source->node_data->getType($base_conditional))
                 && $conditional instanceof PhpParser\Node\Expr\BinaryOp\Identical
             ) {
-                $null_type = Type::getEmptyArray();
+                $empty_array_type = Type::getEmptyArray();
 
-                if (!TypeAnalyzer::isContainedBy(
-                    $codebase,
-                    $var_type,
-                    $null_type
-                ) && !TypeAnalyzer::isContainedBy(
+                if (!TypeAnalyzer::canExpressionTypesBeIdentical(
                     $codebase,
-                    $null_type,
+                    $empty_array_type,
                     $var_type
                 )) {
                     if ($var_type->from_docblock) {

diff --git a/tests/Template/FunctionTemplateTest.php b/tests/Template/FunctionTemplateTest.php
@@ -1254,6 +1254,19 @@ function foo(A $o):void {}
 
                     createProxy(A::class, \'Ns\foo\')->bar();',
             ],
+            'compareToEmptyArray' => [
+                '<?php
+                    /**
+                     * @template T
+                     *
+                     * @param T $a
+                     * @return T
+                     */
+                    function ex($a) {
+                        if($a === []) {}
+                        return $a;
+                    }'
+            ],
         ];
     }