From 2a377ef906dbe9a7d1db9b6b5a6e7ecc6dd9601f Mon Sep 17 00:00:00 2001
From: Theodore Brown <theodorejb@outlook.com>
Date: Sun, 18 Dec 2022 14:06:23 -0600
Subject: [PATCH] Allow conditions inside loops to preserve or narrow int range

Fixes #7555, fixes #8020, fixes #8865
---
 src/Psalm/Internal/Diff/FileDiffer.php        |  2 --
 .../Type/Comparator/ArrayTypeComparator.php   |  4 ---
 .../Type/SimpleAssertionReconciler.php        |  8 -----
 .../Type/SimpleNegatedAssertionReconciler.php |  8 -----
 tests/IntRangeTest.php                        | 32 +++++++++++++++++--
 5 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/src/Psalm/Internal/Diff/FileDiffer.php b/src/Psalm/Internal/Diff/FileDiffer.php
index 6d72bc038ce..4673d21a5c7 100644
--- a/src/Psalm/Internal/Diff/FileDiffer.php
+++ b/src/Psalm/Internal/Diff/FileDiffer.php
@@ -77,8 +77,6 @@ private static function extractDiff(array $trace, int $x, int $y, array $a, arra
     {
         $result = [];
         for ($d = count($trace) - 1; $d >= 0; --$d) {
-            // Todo: fix integer ranges in fors
-            /** @var int<0, max> $d */
             $v = $trace[$d];
             $k = $x - $y;
 
diff --git a/src/Psalm/Internal/Type/Comparator/ArrayTypeComparator.php b/src/Psalm/Internal/Type/Comparator/ArrayTypeComparator.php
index 0e0210a1605..975c6a32e3e 100644
--- a/src/Psalm/Internal/Type/Comparator/ArrayTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/ArrayTypeComparator.php
@@ -123,10 +123,6 @@ public static function isContainedBy(
         }
 
         foreach ($input_type_part->type_params as $i => $input_param) {
-            if ($i > 1) {
-                break;
-            }
-
             $container_param = $container_type_part->type_params[$i];
 
             if ($i === 0
diff --git a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
index f05ba1ef504..4d5c409be33 100644
--- a/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleAssertionReconciler.php
@@ -1962,10 +1962,6 @@ private static function reconcileIsGreaterThan(
         }
 
         foreach ($existing_var_type->getAtomicTypes() as $atomic_type) {
-            if ($inside_loop) {
-                continue;
-            }
-
             if ($atomic_type instanceof TIntRange) {
                 if ($atomic_type->contains($assertion_value)) {
                     // if the range contains the assertion, the range must be adapted
@@ -2075,10 +2071,6 @@ private static function reconcileIsLessThan(
         }
 
         foreach ($existing_var_type->getAtomicTypes() as $atomic_type) {
-            if ($inside_loop) {
-                continue;
-            }
-
             if ($atomic_type instanceof TIntRange) {
                 if ($atomic_type->contains($assertion_value)) {
                     // if the range contains the assertion, the range must be adapted
diff --git a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
index edeef3adb43..9bf3c658a78 100644
--- a/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
+++ b/src/Psalm/Internal/Type/SimpleNegatedAssertionReconciler.php
@@ -1840,10 +1840,6 @@ private static function reconcileIsLessThanOrEqualTo(
         }
 
         foreach ($existing_var_type->getAtomicTypes() as $atomic_type) {
-            if ($inside_loop) {
-                continue;
-            }
-
             if ($atomic_type instanceof TIntRange) {
                 if ($atomic_type->contains($assertion_value)) {
                     // if the range contains the assertion, the range must be adapted
@@ -1951,10 +1947,6 @@ private static function reconcileIsGreaterThanOrEqualTo(
         }
 
         foreach ($existing_var_type->getAtomicTypes() as $atomic_type) {
-            if ($inside_loop) {
-                continue;
-            }
-
             if ($atomic_type instanceof TIntRange) {
                 if ($atomic_type->contains($assertion_value)) {
                     // if the range contains the assertion, the range must be adapted
diff --git a/tests/IntRangeTest.php b/tests/IntRangeTest.php
index 1a9b78a6124..c3e5f51af76 100644
--- a/tests/IntRangeTest.php
+++ b/tests/IntRangeTest.php
@@ -443,9 +443,8 @@ function getInt()
                     '$remainder===' => 'int<min, 1>'
                 ]
             ],
-            'SKIPPED-IntRangeRestrictWhenUntouched' => [
+            'IntRangeRestrictWhenUntouched' => [
                 'code' => '<?php
-                    //skipped, int range in loops not supported yet
                     foreach ([1, 2, 3] as $i) {
                         if ($i > 1) {
                             takesInt($i);
@@ -457,6 +456,35 @@ function takesInt(int $i): void{
                         return;
                     }',
             ],
+            'intRangeExpandedByLoop' => [
+                'code' => '<?php
+                    for ($i = 0; $i < 10; $i++) {
+                        takesInt($i);
+                    }
+                    for (; $i < 20; $i++) {
+                        takesInt($i);
+                    }
+
+                    /** @psalm-param int<0, 20> $i */
+                    function takesInt(int $i): void{
+                        return;
+                    }',
+            ],
+            'statementsInLoopPreserveNonNegativeIntRange' => [
+                'code' => '<?php
+                    $sum = 0;
+                    foreach ([-6, 0, 2] as $i) {
+                        if ($i > 0) {
+                            $sum += $i;
+                        }
+                    }
+                    takesNonNegativeInt($sum);
+
+                    /** @psalm-param int<0, max> $i */
+                    function takesNonNegativeInt(int $i): void{
+                        return;
+                    }',
+            ],
             'SKIPPED-wrongLoopAssertion' => [
                 'code' => '<?php
                     //skipped, int range in loops not supported yet