From dae47bf9404419df34cf497a141c5ba449e46494 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jok=C5=ABbas=20Ramanauskas?= <jokubas.rama@gmail.com>
Date: Wed, 17 Sep 2025 17:48:59 +0300
Subject: [PATCH 1/5] ForbidArithmeticOperationOnNonNumberRule: add support for
 BcMath\Number

---
 ...rbidArithmeticOperationOnNonNumberRule.php | 24 ++++++++-
 ...ArithmeticOperationOnNonNumberRuleTest.php | 21 ++++++++
 .../bcmath-number-no-numeric.php              | 38 +++++++++++++
 .../bcmath-number.php                         | 54 +++++++++++++++++++
 4 files changed, 136 insertions(+), 1 deletion(-)
 create mode 100644 tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php
 create mode 100644 tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php

diff --git a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
index f95f947..493b873 100644
--- a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
+++ b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
@@ -18,6 +18,7 @@
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\Type\FloatType;
 use PHPStan\Type\IntegerType;
+use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
@@ -113,6 +114,12 @@ private function processBinary(
             return []; // array merge syntax
         }
 
+        if (($this->isBcMathNumber($leftType) && $this->isFloat($rightType))
+            || ($this->isFloat($leftType) && $this->isBcMathNumber($rightType))
+        ) {
+            return $this->buildBinaryErrors($operator, 'BcMath\\Number and float', $leftType, $rightType);
+        }
+
         if (
             $operator === '%' &&
             (!$leftType->isInteger()->yes() || !$rightType->isInteger()->yes())
@@ -136,7 +143,8 @@ private function isNumeric(Type $type): bool
         return $int->isSuperTypeOf($type)->yes()
             || $float->isSuperTypeOf($type)->yes()
             || $intOrFloat->isSuperTypeOf($type)->yes()
-            || ($this->allowNumericString && $type->isNumericString()->yes());
+            || ($this->allowNumericString && $type->isNumericString()->yes())
+            || $this->isBcMathNumber($type);
     }
 
     /**
@@ -164,4 +172,18 @@ private function buildBinaryErrors(
         return [$error];
     }
 
+    private function isBcMathNumber(Type $type): bool
+    {
+        $bcMathNumber = new ObjectType('BcMath\Number');
+
+        return $type->isSuperTypeOf($bcMathNumber)->yes();
+    }
+
+    private function isFloat(Type $type): bool
+    {
+        $float = new FloatType();
+
+        return $type->isSuperTypeOf($float)->yes();
+    }
+
 }
diff --git a/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php b/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
index 458030e..a0b340c 100644
--- a/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
+++ b/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
@@ -5,6 +5,7 @@
 use LogicException;
 use PHPStan\Rules\Rule;
 use ShipMonk\PHPStan\RuleTestCase;
+use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<ForbidArithmeticOperationOnNonNumberRule>
@@ -35,6 +36,26 @@ public function testNoNumericString(): void
         $this->analyseFile(__DIR__ . '/data/ForbidArithmeticOperationOnNonNumberRule/no-numeric-string.php');
     }
 
+    public function testBcMathNumber(): void
+    {
+        if (PHP_VERSION_ID < 80_400) {
+            self::markTestSkipped('Requires PHP 8.4');
+        }
+
+        $this->allowNumericString = true;
+        $this->analyseFile(__DIR__ . '/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php');
+    }
+
+    public function testBcMathNumberNoNumeric(): void
+    {
+        if (PHP_VERSION_ID < 80_400) {
+            self::markTestSkipped('Requires PHP 8.4');
+        }
+
+        $this->allowNumericString = false;
+        $this->analyseFile(__DIR__ . '/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php');
+    }
+
     protected function shouldFailOnPhpErrors(): bool
     {
         return false; // https://github.com/phpstan/phpstan-src/pull/3031
diff --git a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php
new file mode 100644
index 0000000..7d198ef
--- /dev/null
+++ b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php
@@ -0,0 +1,38 @@
+<?php declare(strict_types = 1);
+
+namespace ShipMonk\PHPStan\Rule\data\ForbidArithmeticOperationOnNonNumberRule;
+use BcMath\Number;
+
+class BcMathNumberNoNumeric {
+
+    /**
+     * @param numeric-string $ns
+     */
+    public function testBcMathNumbers(Number $n, string $ns, int $int, float $float, int|float $intFloat): void {
+        +$n;
+        -$n;
+
+        $x = $n + $n;
+        $x = $n - $n;
+        $x = $n * $n;
+        $x = $n / $n;
+
+        $x = $n + $int;
+        $x = $int + $n;
+        $x = $n + $ns; // error: Using + over non-number (BcMath\Number + string)
+        $x = $ns + $n; // error: Using + over non-number (string + BcMath\Number)
+        $x = $n - $int;
+        $x = $int - $n;
+        $x = $n - $ns; // error: Using - over non-number (BcMath\Number - string)
+        $x = $ns - $n; // error: Using - over non-number (string - BcMath\Number)
+        $x = $n * $int;
+        $x = $int * $n;
+        $x = $n * $ns; // error: Using * over non-number (BcMath\Number * string)
+        $x = $ns * $n; // error: Using * over non-number (string * BcMath\Number)
+        $x = $n / $int;
+        $x = $int / $n;
+        $x = $n / $ns; // error: Using / over non-number (BcMath\Number / string)
+        $x = $ns / $n; // error: Using / over non-number (string / BcMath\Number)
+    }
+}
+
diff --git a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php
new file mode 100644
index 0000000..4318b84
--- /dev/null
+++ b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php
@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace ForbidArithmeticOperationOnNonNumberRule;
+use BcMath\Number;
+
+class BcMathNumber {
+
+    /**
+     * @param numeric-string $ns
+     */
+    public function testBcMathNumbers(Number $n, string $ns, int $int, float $float, int|float $intFloat): void {
+        +$n;
+        -$n;
+
+        $x = $n + $n;
+        $x = $n - $n;
+        $x = $n * $n;
+        $x = $n / $n;
+
+        $x = $n + $int;
+        $x = $int + $n;
+        $x = $n + $ns;
+        $x = $ns + $n;
+        $x = $n - $int;
+        $x = $int - $n;
+        $x = $n - $ns;
+        $x = $ns - $n;
+        $x = $n * $int;
+        $x = $int * $n;
+        $x = $n * $ns;
+        $x = $ns * $n;
+        $x = $n / $int;
+        $x = $int / $n;
+        $x = $n / $ns;
+        $x = $ns / $n;
+
+        $x = $n + $float; // error: Using + over BcMath\Number and float (BcMath\Number + float)
+        $x = $float + $n; // error: Using + over BcMath\Number and float (float + BcMath\Number)
+        $x = $n - $float; // error: Using - over BcMath\Number and float (BcMath\Number - float)
+        $x = $float - $n; // error: Using - over BcMath\Number and float (float - BcMath\Number)
+        $x = $n * $float; // error: Using * over BcMath\Number and float (BcMath\Number * float)
+        $x = $float * $n; // error: Using * over BcMath\Number and float (float * BcMath\Number)
+        $x = $n / $float; // error: Using / over BcMath\Number and float (BcMath\Number / float)
+        $x = $float / $n; // error: Using / over BcMath\Number and float (float / BcMath\Number)
+        $x = $n % $float; // error: Using % over BcMath\Number and float (BcMath\Number % float)
+        $x = $float % $n; // error: Using % over BcMath\Number and float (float % BcMath\Number)
+        $x = $n ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number ** float)
+        $x = $float ** $n; // error: Using ** over BcMath\Number and float (float ** BcMath\Number)
+
+        $x = $n + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number + float|int)
+        $x = $intFloat + $n; // error: Using + over BcMath\Number and float (float|int + BcMath\Number)
+    }
+}
+

From 8e6295cc60c3aa12ce8d9d49470f23c3b8b5224d Mon Sep 17 00:00:00 2001
From: Jan Nedbal <janedbal@gmail.com>
Date: Mon, 1 Dec 2025 11:12:26 +0100
Subject: [PATCH 2/5] Fix (object + float) classification as BcNumber issue,
 extend test dataset

---
 ...rbidArithmeticOperationOnNonNumberRule.php |  34 +--
 ...ArithmeticOperationOnNonNumberRuleTest.php |   9 -
 .../bcmath-number.php                         | 210 ++++++++++++++----
 3 files changed, 190 insertions(+), 63 deletions(-)

diff --git a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
index 493b873..acd26be 100644
--- a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
+++ b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
@@ -20,6 +20,7 @@
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 use function sprintf;
@@ -114,8 +115,8 @@ private function processBinary(
             return []; // array merge syntax
         }
 
-        if (($this->isBcMathNumber($leftType) && $this->isFloat($rightType))
-            || ($this->isFloat($leftType) && $this->isBcMathNumber($rightType))
+        if (($this->containsBcMathNumber($leftType) && $this->isFloat($rightType))
+            || ($this->isFloat($leftType) && $this->containsBcMathNumber($rightType))
         ) {
             return $this->buildBinaryErrors($operator, 'BcMath\\Number and float', $leftType, $rightType);
         }
@@ -138,13 +139,14 @@ private function isNumeric(Type $type): bool
     {
         $int = new IntegerType();
         $float = new FloatType();
-        $intOrFloat = new UnionType([$int, $float]);
+        $bcNumber = new ObjectType('BcMath\Number');
+        $intOrFloatOrBcNumber = new UnionType([$int, $float, $bcNumber]);
 
         return $int->isSuperTypeOf($type)->yes()
             || $float->isSuperTypeOf($type)->yes()
-            || $intOrFloat->isSuperTypeOf($type)->yes()
-            || ($this->allowNumericString && $type->isNumericString()->yes())
-            || $this->isBcMathNumber($type);
+            || $bcNumber->isSuperTypeOf($type)->yes()
+            || $intOrFloatOrBcNumber->isSuperTypeOf($type)->yes()
+            || ($this->allowNumericString && $type->isNumericString()->yes());
     }
 
     /**
@@ -172,13 +174,6 @@ private function buildBinaryErrors(
         return [$error];
     }
 
-    private function isBcMathNumber(Type $type): bool
-    {
-        $bcMathNumber = new ObjectType('BcMath\Number');
-
-        return $type->isSuperTypeOf($bcMathNumber)->yes();
-    }
-
     private function isFloat(Type $type): bool
     {
         $float = new FloatType();
@@ -186,4 +181,17 @@ private function isFloat(Type $type): bool
         return $type->isSuperTypeOf($float)->yes();
     }
 
+    private function containsBcMathNumber(Type $type): bool
+    {
+        $bcMathFound = false;
+        TypeTraverser::map($type, static function (Type $traversedTyped, callable $traverse) use (&$bcMathFound): Type {
+            $bcMathNumber = new ObjectType('BcMath\Number');
+            if ($bcMathNumber->isSuperTypeOf($traversedTyped)->yes()) {
+                $bcMathFound = true;
+            }
+            return $traverse($traversedTyped);
+        });
+        return $bcMathFound;
+    }
+
 }
diff --git a/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php b/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
index a0b340c..81f938e 100644
--- a/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
+++ b/tests/Rule/ForbidArithmeticOperationOnNonNumberRuleTest.php
@@ -5,7 +5,6 @@
 use LogicException;
 use PHPStan\Rules\Rule;
 use ShipMonk\PHPStan\RuleTestCase;
-use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<ForbidArithmeticOperationOnNonNumberRule>
@@ -38,20 +37,12 @@ public function testNoNumericString(): void
 
     public function testBcMathNumber(): void
     {
-        if (PHP_VERSION_ID < 80_400) {
-            self::markTestSkipped('Requires PHP 8.4');
-        }
-
         $this->allowNumericString = true;
         $this->analyseFile(__DIR__ . '/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php');
     }
 
     public function testBcMathNumberNoNumeric(): void
     {
-        if (PHP_VERSION_ID < 80_400) {
-            self::markTestSkipped('Requires PHP 8.4');
-        }
-
         $this->allowNumericString = false;
         $this->analyseFile(__DIR__ . '/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number-no-numeric.php');
     }
diff --git a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php
index 4318b84..f7dec26 100644
--- a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php
+++ b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/bcmath-number.php
@@ -1,6 +1,7 @@
 <?php declare(strict_types = 1);
 
 namespace ForbidArithmeticOperationOnNonNumberRule;
+
 use BcMath\Number;
 
 class BcMathNumber {
@@ -8,47 +9,174 @@ class BcMathNumber {
     /**
      * @param numeric-string $ns
      */
-    public function testBcMathNumbers(Number $n, string $ns, int $int, float $float, int|float $intFloat): void {
-        +$n;
-        -$n;
-
-        $x = $n + $n;
-        $x = $n - $n;
-        $x = $n * $n;
-        $x = $n / $n;
-
-        $x = $n + $int;
-        $x = $int + $n;
-        $x = $n + $ns;
-        $x = $ns + $n;
-        $x = $n - $int;
-        $x = $int - $n;
-        $x = $n - $ns;
-        $x = $ns - $n;
-        $x = $n * $int;
-        $x = $int * $n;
-        $x = $n * $ns;
-        $x = $ns * $n;
-        $x = $n / $int;
-        $x = $int / $n;
-        $x = $n / $ns;
-        $x = $ns / $n;
-
-        $x = $n + $float; // error: Using + over BcMath\Number and float (BcMath\Number + float)
-        $x = $float + $n; // error: Using + over BcMath\Number and float (float + BcMath\Number)
-        $x = $n - $float; // error: Using - over BcMath\Number and float (BcMath\Number - float)
-        $x = $float - $n; // error: Using - over BcMath\Number and float (float - BcMath\Number)
-        $x = $n * $float; // error: Using * over BcMath\Number and float (BcMath\Number * float)
-        $x = $float * $n; // error: Using * over BcMath\Number and float (float * BcMath\Number)
-        $x = $n / $float; // error: Using / over BcMath\Number and float (BcMath\Number / float)
-        $x = $float / $n; // error: Using / over BcMath\Number and float (float / BcMath\Number)
-        $x = $n % $float; // error: Using % over BcMath\Number and float (BcMath\Number % float)
-        $x = $float % $n; // error: Using % over BcMath\Number and float (float % BcMath\Number)
-        $x = $n ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number ** float)
-        $x = $float ** $n; // error: Using ** over BcMath\Number and float (float ** BcMath\Number)
-
-        $x = $n + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number + float|int)
-        $x = $intFloat + $n; // error: Using + over BcMath\Number and float (float|int + BcMath\Number)
+    public function testBcMathNumbers(
+        object $object,
+        Number $number,
+        string $ns,
+        int $int,
+        float $float,
+        bool|float $boolFloat,
+        int|float $intFloat,
+        Number|int $nInt,
+        Number|float $nFloat,
+        Number|int|float $nIntFloat,
+        Number|int|float|bool $nIntFloatBool
+    ): void {
+        +$number;
+        -$number;
+
+        $x = $object + $float; // error: Using + over non-number (object + float)
+        $x = $object + $number; // error: Using + over non-number (object + BcMath\Number)
+
+        $x = $number + $number;
+        $x = $number - $number;
+        $x = $number * $number;
+        $x = $number / $number;
+
+        $x = $number / $boolFloat; // error: Using / over BcMath\Number and float (BcMath\Number / bool|float)
+
+        $x = $number + $int;
+        $x = $int + $number;
+        $x = $number + $ns;
+        $x = $ns + $number;
+        $x = $number - $int;
+        $x = $int - $number;
+        $x = $number - $ns;
+        $x = $ns - $number;
+        $x = $number * $int;
+        $x = $int * $number;
+        $x = $number * $ns;
+        $x = $ns * $number;
+        $x = $number / $int;
+        $x = $int / $number;
+        $x = $number / $ns;
+        $x = $ns / $number;
+
+        $x = $nInt + $int;
+        $x = $int + $nInt;
+        $x = $nInt + $ns;
+        $x = $ns + $nInt;
+        $x = $nInt - $int;
+        $x = $int - $nInt;
+        $x = $nInt - $ns;
+        $x = $ns - $nInt;
+        $x = $nInt * $int;
+        $x = $int * $nInt;
+        $x = $nInt * $ns;
+        $x = $ns * $nInt;
+        $x = $nInt / $int;
+        $x = $int / $nInt;
+        $x = $nInt / $ns;
+        $x = $ns / $nInt;
+
+        $x = $nFloat + $int;
+        $x = $int + $nFloat;
+        $x = $nFloat + $ns;
+        $x = $ns + $nFloat;
+        $x = $nFloat - $int;
+        $x = $int - $nFloat;
+        $x = $nFloat - $ns;
+        $x = $ns - $nFloat;
+        $x = $nFloat * $int;
+        $x = $int * $nFloat;
+        $x = $nFloat * $ns;
+        $x = $ns * $nFloat;
+        $x = $nFloat / $int;
+        $x = $int / $nFloat;
+        $x = $nFloat / $ns;
+        $x = $ns / $nFloat;
+
+        $x = $nIntFloat + $int;
+        $x = $int + $nIntFloat;
+        $x = $nIntFloat + $ns;
+        $x = $ns + $nIntFloat;
+        $x = $nIntFloat - $int;
+        $x = $int - $nIntFloat;
+        $x = $nIntFloat - $ns;
+        $x = $ns - $nIntFloat;
+        $x = $nIntFloat * $int;
+        $x = $int * $nIntFloat;
+        $x = $nIntFloat * $ns;
+        $x = $ns * $nIntFloat;
+        $x = $nIntFloat / $int;
+        $x = $int / $nIntFloat;
+        $x = $nIntFloat / $ns;
+        $x = $ns / $nIntFloat;
+
+        $x = $number + $float; // error: Using + over BcMath\Number and float (BcMath\Number + float)
+        $x = $float + $number; // error: Using + over BcMath\Number and float (float + BcMath\Number)
+        $x = $number - $float; // error: Using - over BcMath\Number and float (BcMath\Number - float)
+        $x = $float - $number; // error: Using - over BcMath\Number and float (float - BcMath\Number)
+        $x = $number * $float; // error: Using * over BcMath\Number and float (BcMath\Number * float)
+        $x = $float * $number; // error: Using * over BcMath\Number and float (float * BcMath\Number)
+        $x = $number / $float; // error: Using / over BcMath\Number and float (BcMath\Number / float)
+        $x = $float / $number; // error: Using / over BcMath\Number and float (float / BcMath\Number)
+        $x = $number % $float; // error: Using % over BcMath\Number and float (BcMath\Number % float)
+        $x = $float % $number; // error: Using % over BcMath\Number and float (float % BcMath\Number)
+        $x = $number ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number ** float)
+        $x = $float ** $number; // error: Using ** over BcMath\Number and float (float ** BcMath\Number)
+        $x = $number + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number + float|int)
+        $x = $intFloat + $number; // error: Using + over BcMath\Number and float (float|int + BcMath\Number)
+
+        $x = $nInt + $float; // error: Using + over BcMath\Number and float (BcMath\Number|int + float)
+        $x = $float + $nInt; // error: Using + over BcMath\Number and float (float + BcMath\Number|int)
+        $x = $nInt - $float; // error: Using - over BcMath\Number and float (BcMath\Number|int - float)
+        $x = $float - $nInt; // error: Using - over BcMath\Number and float (float - BcMath\Number|int)
+        $x = $nInt * $float; // error: Using * over BcMath\Number and float (BcMath\Number|int * float)
+        $x = $float * $nInt; // error: Using * over BcMath\Number and float (float * BcMath\Number|int)
+        $x = $nInt / $float; // error: Using / over BcMath\Number and float (BcMath\Number|int / float)
+        $x = $float / $nInt; // error: Using / over BcMath\Number and float (float / BcMath\Number|int)
+        $x = $nInt % $float; // error: Using % over BcMath\Number and float (BcMath\Number|int % float)
+        $x = $float % $nInt; // error: Using % over BcMath\Number and float (float % BcMath\Number|int)
+        $x = $nInt ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number|int ** float)
+        $x = $float ** $nInt; // error: Using ** over BcMath\Number and float (float ** BcMath\Number|int)
+        $x = $nInt + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number|int + float|int)
+        $x = $intFloat + $nInt; // error: Using + over BcMath\Number and float (float|int + BcMath\Number|int)
+
+        $x = $nFloat + $float; // error: Using + over BcMath\Number and float (BcMath\Number|float + float)
+        $x = $float + $nFloat; // error: Using + over BcMath\Number and float (float + BcMath\Number|float)
+        $x = $nFloat - $float; // error: Using - over BcMath\Number and float (BcMath\Number|float - float)
+        $x = $float - $nFloat; // error: Using - over BcMath\Number and float (float - BcMath\Number|float)
+        $x = $nFloat * $float; // error: Using * over BcMath\Number and float (BcMath\Number|float * float)
+        $x = $float * $nFloat; // error: Using * over BcMath\Number and float (float * BcMath\Number|float)
+        $x = $nFloat / $float; // error: Using / over BcMath\Number and float (BcMath\Number|float / float)
+        $x = $float / $nFloat; // error: Using / over BcMath\Number and float (float / BcMath\Number|float)
+        $x = $nFloat % $float; // error: Using % over BcMath\Number and float (BcMath\Number|float % float)
+        $x = $float % $nFloat; // error: Using % over BcMath\Number and float (float % BcMath\Number|float)
+        $x = $nFloat ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number|float ** float)
+        $x = $float ** $nFloat; // error: Using ** over BcMath\Number and float (float ** BcMath\Number|float)
+        $x = $nFloat + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number|float + float|int)
+        $x = $intFloat + $nFloat; // error: Using + over BcMath\Number and float (float|int + BcMath\Number|float)
+
+        $x = $nIntFloat + $float; // error: Using + over BcMath\Number and float (BcMath\Number|float|int + float)
+        $x = $float + $nIntFloat; // error: Using + over BcMath\Number and float (float + BcMath\Number|float|int)
+        $x = $nIntFloat - $float; // error: Using - over BcMath\Number and float (BcMath\Number|float|int - float)
+        $x = $float - $nIntFloat; // error: Using - over BcMath\Number and float (float - BcMath\Number|float|int)
+        $x = $nIntFloat * $float; // error: Using * over BcMath\Number and float (BcMath\Number|float|int * float)
+        $x = $float * $nIntFloat; // error: Using * over BcMath\Number and float (float * BcMath\Number|float|int)
+        $x = $nIntFloat / $float; // error: Using / over BcMath\Number and float (BcMath\Number|float|int / float)
+        $x = $float / $nIntFloat; // error: Using / over BcMath\Number and float (float / BcMath\Number|float|int)
+        $x = $nIntFloat % $float; // error: Using % over BcMath\Number and float (BcMath\Number|float|int % float)
+        $x = $float % $nIntFloat; // error: Using % over BcMath\Number and float (float % BcMath\Number|float|int)
+        $x = $nIntFloat ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number|float|int ** float)
+        $x = $float ** $nIntFloat; // error: Using ** over BcMath\Number and float (float ** BcMath\Number|float|int)
+        $x = $nIntFloat + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number|float|int + float|int)
+        $x = $intFloat + $nIntFloat; // error: Using + over BcMath\Number and float (float|int + BcMath\Number|float|int)
+
+        $x = $nIntFloatBool + $float; // error: Using + over BcMath\Number and float (BcMath\Number|bool|float|int + float)
+        $x = $float + $nIntFloatBool; // error: Using + over BcMath\Number and float (float + BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool - $float; // error: Using - over BcMath\Number and float (BcMath\Number|bool|float|int - float)
+        $x = $float - $nIntFloatBool; // error: Using - over BcMath\Number and float (float - BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool * $float; // error: Using * over BcMath\Number and float (BcMath\Number|bool|float|int * float)
+        $x = $float * $nIntFloatBool; // error: Using * over BcMath\Number and float (float * BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool / $float; // error: Using / over BcMath\Number and float (BcMath\Number|bool|float|int / float)
+        $x = $float / $nIntFloatBool; // error: Using / over BcMath\Number and float (float / BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool % $float; // error: Using % over BcMath\Number and float (BcMath\Number|bool|float|int % float)
+        $x = $float % $nIntFloatBool; // error: Using % over BcMath\Number and float (float % BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool ** $float; // error: Using ** over BcMath\Number and float (BcMath\Number|bool|float|int ** float)
+        $x = $float ** $nIntFloatBool; // error: Using ** over BcMath\Number and float (float ** BcMath\Number|bool|float|int)
+        $x = $nIntFloatBool + $intFloat; // error: Using + over BcMath\Number and float (BcMath\Number|bool|float|int + float|int)
+        $x = $intFloat + $nIntFloatBool; // error: Using + over BcMath\Number and float (float|int + BcMath\Number|bool|float|int)
     }
 }
 

From 0f1c9bc580aee8ce2e76ba00a1eba67a08c46c19 Mon Sep 17 00:00:00 2001
From: Jan Nedbal <janedbal@gmail.com>
Date: Mon, 1 Dec 2025 12:44:21 +0100
Subject: [PATCH 3/5] Simplify isNumeric

---
 .../ForbidArithmeticOperationOnNonNumberRule.php   | 14 ++++++--------
 .../code.php                                       |  2 ++
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
index acd26be..c31102c 100644
--- a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
+++ b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
@@ -137,15 +137,13 @@ private function processBinary(
 
     private function isNumeric(Type $type): bool
     {
-        $int = new IntegerType();
-        $float = new FloatType();
-        $bcNumber = new ObjectType('BcMath\Number');
-        $intOrFloatOrBcNumber = new UnionType([$int, $float, $bcNumber]);
+        $numericUnion = new UnionType([
+            new IntegerType(),
+            new FloatType(),
+            new ObjectType('BcMath\Number'),
+        ]);
 
-        return $int->isSuperTypeOf($type)->yes()
-            || $float->isSuperTypeOf($type)->yes()
-            || $bcNumber->isSuperTypeOf($type)->yes()
-            || $intOrFloatOrBcNumber->isSuperTypeOf($type)->yes()
+        return $numericUnion->isSuperTypeOf($type)->yes()
             || ($this->allowNumericString && $type->isNumericString()->yes());
     }
 
diff --git a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/code.php b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/code.php
index 66643fa..3d4a38f 100644
--- a/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/code.php
+++ b/tests/Rule/data/ForbidArithmeticOperationOnNonNumberRule/code.php
@@ -130,6 +130,8 @@ public function testUnions(
         -$intFloat;
         -$intFloatString; // error: Using - over non-number (float|int|string)
         -$intArray; // error: Using - over non-number (array|int)
+
+        $intString - $intArray; // error: Using - over non-number (int|string - array|int)
     }
 
     /**

From 3e02d4c4a25b6a0a94d7a018e32563d2be077cb9 Mon Sep 17 00:00:00 2001
From: Jan Nedbal <janedbal@gmail.com>
Date: Mon, 1 Dec 2025 12:47:05 +0100
Subject: [PATCH 4/5] Minor optimization

---
 src/Rule/ForbidArithmeticOperationOnNonNumberRule.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
index c31102c..af48809 100644
--- a/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
+++ b/src/Rule/ForbidArithmeticOperationOnNonNumberRule.php
@@ -182,8 +182,9 @@ private function isFloat(Type $type): bool
     private function containsBcMathNumber(Type $type): bool
     {
         $bcMathFound = false;
-        TypeTraverser::map($type, static function (Type $traversedTyped, callable $traverse) use (&$bcMathFound): Type {
-            $bcMathNumber = new ObjectType('BcMath\Number');
+        $bcMathNumber = new ObjectType('BcMath\Number');
+
+        TypeTraverser::map($type, static function (Type $traversedTyped, callable $traverse) use (&$bcMathFound, $bcMathNumber): Type {
             if ($bcMathNumber->isSuperTypeOf($traversedTyped)->yes()) {
                 $bcMathFound = true;
             }

From d14dd70736986ad8b2c19161bc342adbb89f078b Mon Sep 17 00:00:00 2001
From: Jan Nedbal <janedbal@gmail.com>
Date: Mon, 1 Dec 2025 12:51:44 +0100
Subject: [PATCH 5/5] Readme adjustment

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index d911a55..0a035f4 100644
--- a/README.md
+++ b/README.md
@@ -227,10 +227,11 @@ class EnforceReadonlyPublicPropertyRule {
 ```
 
 ### forbidArithmeticOperationOnNonNumber
-- Disallows using [arithmetic operators](https://www.php.net/manual/en/language.operators.arithmetic.php) with non-numeric types (only float and int is allowed)
+- Disallows using [arithmetic operators](https://www.php.net/manual/en/language.operators.arithmetic.php) with non-numeric types (only `float`, `int` and `BcMath\Number` is allowed)
 - You can allow numeric-string by using `allowNumericString: true` configuration
 - Modulo operator (`%`) allows only integers as it [emits deprecation otherwise](https://3v4l.org/VpVoq)
 - Plus operator is allowed for merging arrays
+- `float` and `BcMath\Number` cannot be combined as it emits deprecations
 
 ```php
 function add(string $a, string $b) {