From 48a38a377f3fab5d9ab60ec5a785f1c67d0c8a41 Mon Sep 17 00:00:00 2001
From: Mikko Pesari <mikko@pesari.fi>
Date: Mon, 16 Feb 2026 19:41:12 +0200
Subject: [PATCH] Fix BcMath\Number unary plus/minus/bitwise-not

---
 .../InitializerExprTypeResolver.php           | 20 +++++++++++++++++++
 src/Type/ObjectType.php                       |  4 ++++
 tests/PHPStan/Analyser/nsrt/bcmath-number.php | 13 +++++++++---
 .../InvalidUnaryOperationRuleTest.php         | 11 ++++++++++
 .../Operators/data/unary-bcmath-number.php    | 17 ++++++++++++++++
 5 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 tests/PHPStan/Rules/Operators/data/unary-bcmath-number.php

diff --git a/src/Reflection/InitializerExprTypeResolver.php b/src/Reflection/InitializerExprTypeResolver.php
index 2794147dcc..feec1bf2ac 100644
--- a/src/Reflection/InitializerExprTypeResolver.php
+++ b/src/Reflection/InitializerExprTypeResolver.php
@@ -993,6 +993,10 @@ public function getBitwiseAndTypeFromTypes(Type $leftType, Type $rightType): Typ
 			return $this->getNeverType($leftType, $rightType);
 		}
 
+		if ((new ObjectType('BcMath\Number'))->isSuperTypeOf($leftType)->yes()) {
+			return new ErrorType();
+		}
+
 		$result = $this->getFiniteOrConstantScalarTypes($leftType, $rightType, static fn ($a, $b) => $a & $b);
 		if ($result instanceof Type) {
 			return $result;
@@ -1051,6 +1055,10 @@ public function getBitwiseOrTypeFromTypes(Type $leftType, Type $rightType): Type
 			return $this->getNeverType($leftType, $rightType);
 		}
 
+		if ((new ObjectType('BcMath\Number'))->isSuperTypeOf($leftType)->yes()) {
+			return new ErrorType();
+		}
+
 		$result = $this->getFiniteOrConstantScalarTypes($leftType, $rightType, static fn ($a, $b) => $a | $b);
 		if ($result instanceof Type) {
 			return $result;
@@ -1159,6 +1167,10 @@ public function getBitwiseXorTypeFromTypes(Type $leftType, Type $rightType): Typ
 			return $this->getNeverType($leftType, $rightType);
 		}
 
+		if ((new ObjectType('BcMath\Number'))->isSuperTypeOf($leftType)->yes()) {
+			return new ErrorType();
+		}
+
 		$result = $this->getFiniteOrConstantScalarTypes($leftType, $rightType, static fn ($a, $b) => $a ^ $b);
 		if ($result instanceof Type) {
 			return $result;
@@ -1765,6 +1777,10 @@ public function getShiftLeftTypeFromTypes(Expr $left, Expr $right, Type $leftTyp
 			return $this->getNeverType($leftType, $rightType);
 		}
 
+		if ((new ObjectType('BcMath\Number'))->isSuperTypeOf($leftType)->yes()) {
+			return new ErrorType();
+		}
+
 		$leftTypes = $leftType->getConstantScalarTypes();
 		$rightTypes = $rightType->getConstantScalarTypes();
 		$leftTypesCount = count($leftTypes);
@@ -1829,6 +1845,10 @@ public function getShiftRightTypeFromTypes(Expr $left, Expr $right, Type $leftTy
 			return $this->getNeverType($leftType, $rightType);
 		}
 
+		if ((new ObjectType('BcMath\Number'))->isSuperTypeOf($leftType)->yes()) {
+			return new ErrorType();
+		}
+
 		$leftTypes = $leftType->getConstantScalarTypes();
 		$rightTypes = $rightType->getConstantScalarTypes();
 		$leftTypesCount = count($leftTypes);
diff --git a/src/Type/ObjectType.php b/src/Type/ObjectType.php
index 8e295b9fc4..634770df9b 100644
--- a/src/Type/ObjectType.php
+++ b/src/Type/ObjectType.php
@@ -762,6 +762,10 @@ public function toNumber(): Type
 			]);
 		}
 
+		if ($this->isInstanceOf('BcMath\Number')->yes()) {
+			return new ObjectType('BcMath\Number');
+		}
+
 		return new ErrorType();
 	}
 
diff --git a/tests/PHPStan/Analyser/nsrt/bcmath-number.php b/tests/PHPStan/Analyser/nsrt/bcmath-number.php
index d78887e4ef..9002f9ce6c 100644
--- a/tests/PHPStan/Analyser/nsrt/bcmath-number.php
+++ b/tests/PHPStan/Analyser/nsrt/bcmath-number.php
@@ -380,9 +380,9 @@ public function bcVsNever(Number $a): void
 	{
 		for ($b = 1; $b < count([]); $b++) {
 			assertType('*NEVER*', $a + $b);
-			assertType('*ERROR*', $a - $b); // Inconsistency: getPlusType handles never types right at the beginning, getMinusType doesn't.
-			assertType('*ERROR*', $a * $b);
-			assertType('*ERROR*', $a / $b);
+			assertType('*NEVER*', $a - $b);
+			assertType('*NEVER*', $a * $b);
+			assertType('*NEVER*', $a / $b);
 			assertType('*NEVER*', $a % $b);
 			assertType('non-empty-string&numeric-string', $a . $b);
 			assertType('*ERROR*', $a ** $b);
@@ -413,4 +413,11 @@ public function bcIncDec(Number $a): void
 		assertType('BcMath\Number', --$a);
 		assertType('BcMath\Number', $a--);
 	}
+
+	public function bcUnaryOp(Number $a): void
+	{
+		assertType('BcMath\Number', +$a);
+		assertType('BcMath\Number', -$a);
+		assertType('*ERROR*', ~$a);
+	}
 }
diff --git a/tests/PHPStan/Rules/Operators/InvalidUnaryOperationRuleTest.php b/tests/PHPStan/Rules/Operators/InvalidUnaryOperationRuleTest.php
index 7300106db7..5fc873675a 100644
--- a/tests/PHPStan/Rules/Operators/InvalidUnaryOperationRuleTest.php
+++ b/tests/PHPStan/Rules/Operators/InvalidUnaryOperationRuleTest.php
@@ -169,4 +169,15 @@ public function testUnion(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.4')]
+	public function testBcMathNumber(): void
+	{
+		$this->analyse([__DIR__ . '/data/unary-bcmath-number.php'], [
+			[
+				'Unary operation "~" on BcMath\Number results in an error.',
+				16,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Operators/data/unary-bcmath-number.php b/tests/PHPStan/Rules/Operators/data/unary-bcmath-number.php
new file mode 100644
index 0000000000..de1dbbcab6
--- /dev/null
+++ b/tests/PHPStan/Rules/Operators/data/unary-bcmath-number.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace BcMathNumberUnaryOperators;
+
+use BcMath\Number;
+
+function testUnaryPlus(Number $x): void {
+	+$x;
+}
+
+function testUnaryMinus(Number $x): void {
+	-$x;
+}
+
+function testBitwiseNot(Number $x): void {
+	~$x;
+}