From ed82443bc7c8831c2d41bc228aaf4120dde571e6 Mon Sep 17 00:00:00 2001
From: Theodore Brown <theodorejb@outlook.com>
Date: Sun, 8 May 2022 23:40:04 -0500
Subject: [PATCH] Infer object shape when array or scalar is cast to object

Also detect redundant object casts.

Fixes #7916, fixes #7934
---
 .../Statements/Expression/CastAnalyzer.php    | 57 ++++++++++++++-----
 tests/ArgTest.php                             | 13 +++++
 .../ReturnTypeProvider/GetObjectVarsTest.php  |  8 ++-
 tests/ReturnTypeTest.php                      | 38 +++++++++++++
 4 files changed, 101 insertions(+), 15 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
index 35400570ab9..9ffea8807c3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
@@ -183,22 +183,44 @@ public static function analyze(
         }
 
         if ($stmt instanceof PhpParser\Node\Expr\Cast\Object_) {
-            $was_inside_general_use = $context->inside_general_use;
-            $context->inside_general_use = true;
-            if (ExpressionAnalyzer::analyze($statements_analyzer, $stmt->expr, $context) === false) {
-                $context->inside_general_use = $was_inside_general_use;
+            $result = self::checkExprGeneralUse($statements_analyzer, $stmt, $context);
 
+            if (!$result) {
                 return false;
             }
-            $context->inside_general_use = $was_inside_general_use;
 
-            $type = new Union([new TNamedObject('stdClass')]);
+            $permissible_atomic_types = [];
+            $all_permissible = false;
 
-            $maybe_type = $statements_analyzer->node_data->getType($stmt->expr);
+            if ($stmt_expr_type = $statements_analyzer->node_data->getType($stmt->expr)) {
+                if ($stmt_expr_type->isObjectType()) {
+                    self::handleRedundantCast($stmt_expr_type, $statements_analyzer, $stmt);
+                }
+
+                $all_permissible = true;
+
+                foreach ($stmt_expr_type->getAtomicTypes() as $type) {
+                    if ($type instanceof Scalar) {
+                        $objWithProps = new TObjectWithProperties(['scalar' => new Union([$type])]);
+                        $permissible_atomic_types[] = $objWithProps;
+                    } elseif ($type instanceof TKeyedArray) {
+                        $permissible_atomic_types[] = new TObjectWithProperties($type->properties);
+                    } else {
+                        $all_permissible = false;
+                        break;
+                    }
+                }
+            }
+
+            if ($permissible_atomic_types && $all_permissible) {
+                $type = TypeCombiner::combine($permissible_atomic_types);
+            } else {
+                $type = Type::getObject();
+            }
 
             if ($statements_analyzer->data_flow_graph instanceof VariableUseGraph
             ) {
-                $type->parent_nodes = $maybe_type->parent_nodes ?? [];
+                $type->parent_nodes = $stmt_expr_type->parent_nodes ?? [];
             }
 
             $statements_analyzer->node_data->setType($stmt, $type);
@@ -207,14 +229,11 @@ public static function analyze(
         }
 
         if ($stmt instanceof PhpParser\Node\Expr\Cast\Array_) {
-            $was_inside_general_use = $context->inside_general_use;
-            $context->inside_general_use = true;
-            if (ExpressionAnalyzer::analyze($statements_analyzer, $stmt->expr, $context) === false) {
-                $context->inside_general_use = $was_inside_general_use;
+            $result = self::checkExprGeneralUse($statements_analyzer, $stmt, $context);
 
+            if (!$result) {
                 return false;
             }
-            $context->inside_general_use = $was_inside_general_use;
 
             $permissible_atomic_types = [];
             $all_permissible = false;
@@ -457,6 +476,18 @@ public static function castStringAttempt(
         return $str_type;
     }
 
+    private static function checkExprGeneralUse(
+        StatementsAnalyzer $statements_analyzer,
+        PhpParser\Node\Expr\Cast $stmt,
+        Context $context
+    ): bool {
+        $was_inside_general_use = $context->inside_general_use;
+        $context->inside_general_use = true;
+        $retVal = ExpressionAnalyzer::analyze($statements_analyzer, $stmt->expr, $context);
+        $context->inside_general_use = $was_inside_general_use;
+        return $retVal;
+    }
+
     private static function handleRedundantCast(
         Union $maybe_type,
         StatementsAnalyzer $statements_analyzer,
diff --git a/tests/ArgTest.php b/tests/ArgTest.php
index 4354f308f2b..de57435f0e9 100644
--- a/tests/ArgTest.php
+++ b/tests/ArgTest.php
@@ -702,6 +702,19 @@ function takesObject($_o): void {}
                 ',
                 'error_message' => 'ArgumentTypeCoercion',
             ],
+            'objectRedundantCast' => [
+                '<?php
+
+                    function makeObj(): object {
+                        return (object)["a" => 42];
+                    }
+
+                    function takesObject(object $_o): void {}
+
+                    takesObject((object)makeObj()); // expected: RedundantCast
+                ',
+                'error_message' => 'RedundantCast',
+            ],
             'MissingMandatoryParamWithNamedParams' => [
                 '<?php
                 class User
diff --git a/tests/ReturnTypeProvider/GetObjectVarsTest.php b/tests/ReturnTypeProvider/GetObjectVarsTest.php
index cec41706c2c..10dd24dcab8 100644
--- a/tests/ReturnTypeProvider/GetObjectVarsTest.php
+++ b/tests/ReturnTypeProvider/GetObjectVarsTest.php
@@ -90,10 +90,14 @@ function f(object $p): array {
             [],
         ];
 
+        yield 'propertiesOfCastScalar' => [
+            '<?php $ret = get_object_vars((object)true);',
+            ['$ret' => 'array{scalar: true}'],
+        ];
+
         yield 'propertiesOfPOPO' => [
-            // todo: fix object cast so that it results in `object{a:1}` instead
             '<?php $ret = get_object_vars((object)["a" => 1]);',
-            ['$ret' => 'array<string, mixed>'],
+            ['$ret' => 'array{a: int}'],
         ];
     }
 }
diff --git a/tests/ReturnTypeTest.php b/tests/ReturnTypeTest.php
index 53be10b286e..492044b7436 100644
--- a/tests/ReturnTypeTest.php
+++ b/tests/ReturnTypeTest.php
@@ -855,6 +855,33 @@ function map(callable $predicate): callable {
                     '$res' => 'iterable<int, numeric-string>',
                 ],
             ],
+            'infersObjectShapeOfCastScalar' => [
+                '<?php
+                    function returnsInt(): int {
+                        return 1;
+                    }
+
+                    $obj = (object)returnsInt();
+                ',
+                'assertions' => [
+                    '$obj' => 'object{scalar:int}',
+                ],
+            ],
+            'infersObjectShapeOfCastArray' => [
+                '<?php
+                    /**
+                     * @return array{a:1}
+                     */
+                    function returnsArray(): array {
+                        return ["a" => 1];
+                    }
+
+                    $obj = (object)returnsArray();
+                ',
+                'assertions' => [
+                    '$obj' => 'object{a:int}',
+                ],
+            ],
             'mixedAssignmentWithUnderscore' => [
                 '<?php
                     $gen = (function (): Generator {
@@ -1542,6 +1569,17 @@ function f(): object {
                 ',
                 'error_message' => 'LessSpecificReturnStatement',
             ],
+            'objectCastFromArrayWithMissingKey' => [
+                '<?php
+                    /** @return object{status: string} */
+                    function foo(): object {
+                        return (object) [
+                            "notstatus" => "failed",
+                        ];
+                    }
+                ',
+                'error_message' => 'InvalidReturnStatement',
+            ],
             'lessSpecificImplementedReturnTypeFromTemplatedTraitMethod' => [
                 '<?php
                     /** @template T */