From 5bb9ebf8226ecc5924cf7cc2bdc3c6077bc8bad4 Mon Sep 17 00:00:00 2001
From: kkmuffme <11071985+kkmuffme@users.noreply.github.com>
Date: Fri, 3 May 2024 21:43:19 +0200
Subject: [PATCH] Casting int-range should keep literals

Fix https://github.com/vimeo/psalm/issues/10940
500 limit taken from TypeCombiner
---
 .../Statements/Expression/CastAnalyzer.php    | 24 ++++++++++++++++++-
 tests/CastTest.php                            | 10 ++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
index 5832bb159fe..dbb659f9ff6 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php
@@ -28,6 +28,7 @@
 use Psalm\Type\Atomic\TFalse;
 use Psalm\Type\Atomic\TFloat;
 use Psalm\Type\Atomic\TInt;
+use Psalm\Type\Atomic\TIntRange;
 use Psalm\Type\Atomic\TKeyedArray;
 use Psalm\Type\Atomic\TList;
 use Psalm\Type\Atomic\TLiteralFloat;
@@ -53,6 +54,7 @@
 use function array_pop;
 use function array_values;
 use function get_class;
+use function range;
 use function strtolower;
 
 /**
@@ -537,6 +539,18 @@ public static function castFloatAttempt(
                 continue;
             }
 
+            if ($atomic_type instanceof TIntRange
+                && $atomic_type->min_bound !== null
+                && $atomic_type->max_bound !== null
+                && ($atomic_type->max_bound - $atomic_type->min_bound) < 500
+            ) {
+                foreach (range($atomic_type->min_bound, $atomic_type->max_bound) as $literal_int_value) {
+                    $valid_floats[] = new TLiteralFloat((float) $literal_int_value);
+                }
+
+                continue;
+            }
+
             if ($atomic_type instanceof TInt) {
                 if ($atomic_type instanceof TLiteralInt) {
                     $valid_floats[] = new TLiteralFloat((float) $atomic_type->value);
@@ -721,9 +735,17 @@ public static function castStringAttempt(
                 || $atomic_type instanceof TNumeric
             ) {
                 if ($atomic_type instanceof TLiteralInt || $atomic_type instanceof TLiteralFloat) {
-                    $castable_types[] = Type::getAtomicStringFromLiteral((string) $atomic_type->value);
+                    $valid_strings[] = Type::getAtomicStringFromLiteral((string) $atomic_type->value);
                 } elseif ($atomic_type instanceof TNonspecificLiteralInt) {
                     $castable_types[] = new TNonspecificLiteralString();
+                } elseif ($atomic_type instanceof TIntRange
+                    && $atomic_type->min_bound !== null
+                    && $atomic_type->max_bound !== null
+                    && ($atomic_type->max_bound - $atomic_type->min_bound) < 500
+                ) {
+                    foreach (range($atomic_type->min_bound, $atomic_type->max_bound) as $literal_int_value) {
+                        $valid_strings[] = Type::getAtomicStringFromLiteral((string) $literal_int_value);
+                    }
                 } else {
                     $castable_types[] = new TNumericString();
                 }
diff --git a/tests/CastTest.php b/tests/CastTest.php
index fe93e5d7b3f..414aa70aedb 100644
--- a/tests/CastTest.php
+++ b/tests/CastTest.php
@@ -49,5 +49,15 @@ public function providerValidCodeParse(): iterable
                 '$a===' => 'array{a: int, b: string, ...<array-key, mixed>}',
             ],
         ];
+        yield 'castIntRangeToString' => [
+            'code' => '<?php
+                /** @var int<-5, 3> */
+                $int_range = 2;
+                $string = (string) $int_range;
+            ',
+            'assertions' => [
+                '$string===' => "'-1'|'-2'|'-3'|'-4'|'-5'|'0'|'1'|'2'|'3'",
+            ],
+        ];
     }
 }