From 6efaf474d4d6ba0520ef7955c021a23f4d14033c Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Sun, 23 Aug 2020 13:58:34 -0400
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20add=20@psalm-pure=20for=20void-?=
 =?UTF-8?q?returning=20functions?=
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---
 .../Analyzer/FunctionLikeAnalyzer.php         | 26 ++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
index bd816df22..b4c8dcbd6 100644
--- a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
@@ -593,7 +593,31 @@ abstract class FunctionLikeAnalyzer extends SourceAnalyzer
                 $this->function
             );
 
-            $manipulator->makePure();
+            $yield_types = [];
+
+            $inferred_return_types = ReturnTypeCollector::getReturnTypes(
+                $codebase,
+                $type_provider,
+                $function_stmts,
+                $yield_types,
+                true
+            );
+
+            $inferred_return_type = $inferred_return_types
+                ? \Psalm\Type::combineUnionTypeArray(
+                    $inferred_return_types,
+                    $codebase
+                )
+                : null;
+
+            if ($inferred_return_type
+                && !$inferred_return_type->isVoid()
+                && !$inferred_return_type->isFalse()
+                && !$inferred_return_type->isTrue()
+                && !$inferred_return_type->getId() !== 'array<empty, empty>'
+            ) {
+                $manipulator->makePure();
+            }
         }
 
         if (!$context->collect_initializations