From d72b74f0a0d47a5d554dc153a780e16263ce00c3 Mon Sep 17 00:00:00 2001
From: Daniel Leech <daniel@dantleech.com>
Date: Mon, 11 Mar 2024 22:23:49 +0000
Subject: [PATCH] gh-2576: Basic array_reduce stub

---
 CHANGELOG.md                                  |  7 ++++
 .../FunctionStub/ArrayReduceStub.php          | 12 +++----
 .../Resolver/AssignmentExpressionResolver.php | 12 ++++---
 lib/WorseReflection/Core/Type/ArrayType.php   | 11 +++++++
 .../Inference/function/array_reduce.test      | 33 ++++++++++++++++---
 5 files changed, 57 insertions(+), 18 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7fa8c4633a..9e2bd84a79 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,13 @@
 Changelog
 =========
 
+## master
+
+Improvements:
+
+  - Basic support for `array_reduce` stub #2576
+
+
 ## 2024-03-09
 
 Features:
diff --git a/lib/WorseReflection/Core/Inference/FunctionStub/ArrayReduceStub.php b/lib/WorseReflection/Core/Inference/FunctionStub/ArrayReduceStub.php
index 107fc2b36d..639bb4e86d 100644
--- a/lib/WorseReflection/Core/Inference/FunctionStub/ArrayReduceStub.php
+++ b/lib/WorseReflection/Core/Inference/FunctionStub/ArrayReduceStub.php
@@ -7,7 +7,6 @@
 use Phpactor\WorseReflection\Core\Inference\FunctionStub;
 use Phpactor\WorseReflection\Core\Inference\NodeContext;
 use Phpactor\WorseReflection\Core\TypeFactory;
-use Phpactor\WorseReflection\Core\Type\ClosureType;
 
 class ArrayReduceStub implements FunctionStub
 {
@@ -16,15 +15,12 @@ public function resolve(
         NodeContext $context,
         FunctionArguments $args
     ): NodeContext {
-        if (!$args->at(0)->type()->isDefined()) {
-            return $context;
+        $initialType = $args->at(2)->type();
+        if ($initialType->isDefined()) {
+            return $context->withType($initialType->generalize());
         }
 
-        $closureType = $args->at(1);
-        if (!$closureType instanceof ClosureType) {
-            return $context;
-        }
+        return $context->withType(TypeFactory::array());
 
-        return $context->withType(TypeFactory::array($closureType->returnType()));
     }
 }
diff --git a/lib/WorseReflection/Core/Inference/Resolver/AssignmentExpressionResolver.php b/lib/WorseReflection/Core/Inference/Resolver/AssignmentExpressionResolver.php
index c6e99efd2a..b2cd2eb108 100644
--- a/lib/WorseReflection/Core/Inference/Resolver/AssignmentExpressionResolver.php
+++ b/lib/WorseReflection/Core/Inference/Resolver/AssignmentExpressionResolver.php
@@ -179,11 +179,13 @@ private function walkSubscriptExpression(NodeContextResolver $resolver, Frame $f
                         return;
                     }
 
-                    $frame->locals()->set(
-                        $variable->withType(
-                            $type->set($accessType->value(), $rightContext->type())
-                        )->withOffset($leftOperand->getStartPosition())
-                    );
+                    if ($type instanceof ArrayLiteral) {
+                        $frame->locals()->set(
+                            $variable->withType(
+                                $type->set($accessType->value(), $rightContext->type())
+                            )->withOffset($leftOperand->getStartPosition())
+                        );
+                    }
                     continue;
                 }
 
diff --git a/lib/WorseReflection/Core/Type/ArrayType.php b/lib/WorseReflection/Core/Type/ArrayType.php
index 65bd871ef7..4b909cfcbb 100644
--- a/lib/WorseReflection/Core/Type/ArrayType.php
+++ b/lib/WorseReflection/Core/Type/ArrayType.php
@@ -54,4 +54,15 @@ public function allTypes(): Types
     {
         return (new Types([TypeFactory::array()]))->merge(parent::allTypes());
     }
+
+    public function add(Type $type): self
+    {
+        if (null === $this->valueType) {
+            return new self($this->keyType, $type);
+        }
+        if (!$this->valueType->isDefined()) {
+            return new self($this->keyType, $type);
+        }
+        return new self($this->keyType, $this->valueType->addType($type));
+    }
 }
diff --git a/lib/WorseReflection/Tests/Inference/function/array_reduce.test b/lib/WorseReflection/Tests/Inference/function/array_reduce.test
index 285cdc721b..8e93d82f65 100644
--- a/lib/WorseReflection/Tests/Inference/function/array_reduce.test
+++ b/lib/WorseReflection/Tests/Inference/function/array_reduce.test
@@ -1,7 +1,30 @@
 <?php
 
-    array_reduce(['foobar'], function (array $carry, string $foo): array {
-        $carry[] = $foo;
-        wrAssertType('array<string>', $carry);
-        return $carry;
-    }, []),
+$reduced = array_reduce(['foobar'], function (int $carry, string $foo): int {
+}, 0);
+
+wrAssertType('int', $reduced);
+
+$reduced = array_reduce(['foobar'], function (int $carry, string $foo): int {
+}, ['string']);
+
+wrAssertType('array<int,string>', $reduced);
+
+
+// we cannot currently analyze the closure to determine the 
+$reduced = array_reduce(['foobar'], function (array $carry, string $foo): int {
+    $carry[] = 'foo';
+    return $carry;
+}, []);
+
+// should be string[] but we can't currently analyze the closure frames return type
+wrAssertType('array', $reduced);
+
+$reduced = array_reduce(['foobar'], function (int $carry, string $foo): int {
+}, '');
+
+wrAssertType('string', $reduced);
+
+$reduced = array_reduce(['foobar'], function (int $carry, string $foo): int {
+});
+wrAssertType('array', $reduced);