From 350df114f309a83fe9ec2102fdfcbd8867ed71d2 Mon Sep 17 00:00:00 2001
From: orklah <orklah@users.noreply.github.com>
Date: Sun, 23 May 2021 20:43:30 +0200
Subject: [PATCH] Transform bad offsets (#5817)

* Transform bad offset access

* fix build
---
 .../Statements/Expression/ArrayAnalyzer.php   |  2 +
 .../Expression/Fetch/ArrayFetchAnalyzer.php   | 44 +++++++++++++++++++
 tests/ArrayAccessTest.php                     | 15 +++++++
 3 files changed, 61 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
index d59462f4e7c..d5a95a8f4ac 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/ArrayAnalyzer.php
@@ -186,6 +186,8 @@ public static function analyze(
                     } elseif ($atomic_key_type instanceof Type\Atomic\TBool) {
                         $good_types[] = new Type\Atomic\TLiteralInt(0);
                         $good_types[] = new Type\Atomic\TLiteralInt(1);
+                    } elseif ($atomic_key_type instanceof Type\Atomic\TLiteralFloat) {
+                        $good_types[] = new Type\Atomic\TLiteralInt((int) $atomic_key_type->value);
                     } elseif ($atomic_key_type instanceof Type\Atomic\TFloat) {
                         $good_types[] = new Type\Atomic\TInt;
                     } else {
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
index 92d81fc46ab..02da490e8c3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
@@ -11,6 +11,7 @@
 use Psalm\Internal\Type\TemplateInferredTypeReplacer;
 use Psalm\CodeLocation;
 use Psalm\Context;
+use Psalm\Internal\Type\TypeCombiner;
 use Psalm\Issue\EmptyArrayAccess;
 use Psalm\Issue\InvalidArrayAccess;
 use Psalm\Issue\InvalidArrayAssignment;
@@ -426,6 +427,10 @@ public static function taintArrayFetch(
         }
     }
 
+    /**
+     * @psalm-suppress ComplexMethod to be refactored.
+     * Good type/bad type behaviour could be mutualised with ArrayAnalyzer
+     */
     public static function getArrayAccessTypeGivenOffset(
         StatementsAnalyzer $statements_analyzer,
         PhpParser\Node\Expr\ArrayDimFetch $stmt,
@@ -806,6 +811,45 @@ public static function getArrayAccessTypeGivenOffset(
                         }
                     }
                 } else {
+                    $good_types = [];
+                    $bad_types = [];
+                    foreach ($offset_type->getAtomicTypes() as $atomic_key_type) {
+                        if (!$atomic_key_type instanceof Type\Atomic\TString
+                            && !$atomic_key_type instanceof Type\Atomic\TInt
+                            && !$atomic_key_type instanceof Type\Atomic\TArrayKey
+                            && !$atomic_key_type instanceof Type\Atomic\TMixed
+                            && !$atomic_key_type instanceof Type\Atomic\TTemplateParam
+                            && !(
+                                $atomic_key_type instanceof Type\Atomic\TObjectWithProperties
+                                && isset($atomic_key_type->methods['__toString'])
+                            )
+                        ) {
+                            $bad_types[] = $atomic_key_type;
+
+                            if ($atomic_key_type instanceof Type\Atomic\TFalse) {
+                                $good_types[] = new Type\Atomic\TLiteralInt(0);
+                            } elseif ($atomic_key_type instanceof Type\Atomic\TTrue) {
+                                $good_types[] = new Type\Atomic\TLiteralInt(1);
+                            } elseif ($atomic_key_type instanceof Type\Atomic\TBool) {
+                                $good_types[] = new Type\Atomic\TLiteralInt(0);
+                                $good_types[] = new Type\Atomic\TLiteralInt(1);
+                            } elseif ($atomic_key_type instanceof Type\Atomic\TLiteralFloat) {
+                                $good_types[] = new Type\Atomic\TLiteralInt((int)$atomic_key_type->value);
+                            } elseif ($atomic_key_type instanceof Type\Atomic\TFloat) {
+                                $good_types[] = new Type\Atomic\TInt;
+                            } else {
+                                $good_types[] = new Type\Atomic\TArrayKey;
+                            }
+                        }
+                    }
+
+                    if ($bad_types && $good_types) {
+                        $offset_type->substitute(
+                            TypeCombiner::combine($bad_types, $codebase),
+                            TypeCombiner::combine($good_types, $codebase)
+                        );
+                    }
+
                     if (IssueBuffer::accepts(
                         new InvalidArrayOffset(
                             'Cannot access value on variable ' . $array_var_id . ' ' . $used_offset
diff --git a/tests/ArrayAccessTest.php b/tests/ArrayAccessTest.php
index 445adc34c17..4fdc6375f64 100644
--- a/tests/ArrayAccessTest.php
+++ b/tests/ArrayAccessTest.php
@@ -1002,6 +1002,21 @@ function foo(?array $arr, string $s) : void {
                         echo $arr[$s]["c"];
                     }'
             ],
+            'TransformBadOffsetToGoodOnes' => [
+                '<?php
+                    $index = 1.1;
+
+                    /** @psalm-suppress InvalidArrayOffset */
+                    $_arr1 = [$index => 5];
+
+                    $_arr2 = [];
+                    /** @psalm-suppress InvalidArrayOffset */
+                    $_arr2[$index] = 5;',
+                [
+                    '$_arr1===' => 'non-empty-array<1, 5>',
+                    '$_arr2===' => 'non-empty-array<1, 5>',
+                ]
+            ],
         ];
     }