Fix TypeError dead catch when assigning mixed to int in property

src/Analyser/NodeScopeResolver.php

@@ -6366,8 +6366,23 @@
 				$declaringClass = $propertyReflection->getDeclaringClass();
 				if ($declaringClass->hasNativeProperty($propertyName)) {
 					$nativeProperty = $declaringClass->getNativeProperty($propertyName);
+					$propertyNativeType = $nativeProperty->getNativeType();
+
+					$assignedTypeIsCompatible = $propertyNativeType->isSuperTypeOf($assignedExprType)->yes();
+					if (!$assignedTypeIsCompatible && !$assignedExprType instanceof MixedType) {
+						foreach (TypeUtils::flattenTypes($assignedExprType->toCoercedArgumentType(true)) as $type) {
+							$accepts = $propertyNativeType->accepts($type, true);
+							if ($accepts->yes()) {
+								$assignedTypeIsCompatible = true;
+								continue;
+							}
+							$assignedTypeIsCompatible = false;
+							break;
+						}
+					}
+
 					if (
-						!$nativeProperty->getNativeType()->accepts($assignedExprType, true)->yes()
+						!$assignedTypeIsCompatible
 					) {
 						$throwPoints[] = InternalThrowPoint::createExplicit($scope, new ObjectType(TypeError::class), $assignedExpr, false);
 					}

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php

@@ -643,4 +643,32 @@ public function testPropertyHooks(): void
 		]);
 	}
 
+	public function testBug9146(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-9146.php'], [
+			[
+				'Dead catch - TypeError is never thrown in the try block.',
+				52,
+			],
+			[
+				'Dead catch - TypeError is never thrown in the try block.',
+				80,
+			],
+		]);
+	}
+
+	public function testBug9146NonStrict(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-9146-non-strict.php'], [
+			[
+				'Dead catch - TypeError is never thrown in the try block.',
+				52,
+			],
+			[
+				'Dead catch - TypeError is never thrown in the try block.',
+				80,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Exceptions/data/bug-9146-non-strict.php

@@ -0,0 +1,97 @@
+<?php declare(strict_types = 0);
+
+namespace Bug9146NonStrict;
+
+final class HelloWorld
+{
+	public int $number;
+	public function __construct(mixed $number)
+	{
+		try {
+			$this->number = $number;
+		} catch (\TypeError $e) {
+			throw new \UnexpectedValueException();
+		}
+	}
+}
+
+final class HelloWorld2
+{
+	public string $name;
+	public function setName(mixed $value): void
+	{
+		try {
+			$this->name = $value;
+		} catch (\TypeError $e) {
+			throw new \InvalidArgumentException('Expected string');
+		}
+	}
+}
+
+final class HelloWorld3
+{
+	public float $amount;
+	public function setAmount(mixed $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}
+
+// Dead catch: int assigned to ?float, PHP coerces int to float without TypeError
+final class FloatNullCoercion
+{
+	public ?float $amount;
+	public function setAmount(int $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) { // error: Dead catch - TypeError is never thrown in the try block.
+			echo "caught";
+		}
+	}
+}
+
+// Not dead: int|string assigned to int, string part could throw TypeError
+final class PartialTypeMatch
+{
+	public int $number;
+	/** @param int|string $value */
+	public function setNumber($value): void
+	{
+		try {
+			$this->number = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}
+
+final class MixedWillNotThrow
+{
+	public mixed $name;
+	public function setName(mixed $value): void
+	{
+		try {
+			$this->name = $value;
+		} catch (\TypeError $e) {
+			throw new \InvalidArgumentException('Expected string');
+		}
+	}
+}
+
+final class IntJustWarnsOnFloat
+{
+	public int $amount;
+	public function setAmount(float $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}

tests/PHPStan/Rules/Exceptions/data/bug-9146.php

@@ -0,0 +1,97 @@
+<?php declare(strict_types = 1);
+
+namespace Bug9146;
+
+final class HelloWorld
+{
+	public int $number;
+	public function __construct(mixed $number)
+	{
+		try {
+			$this->number = $number;
+		} catch (\TypeError $e) {
+			throw new \UnexpectedValueException();
+		}
+	}
+}
+
+final class HelloWorld2
+{
+	public string $name;
+	public function setName(mixed $value): void
+	{
+		try {
+			$this->name = $value;
+		} catch (\TypeError $e) {
+			throw new \InvalidArgumentException('Expected string');
+		}
+	}
+}
+
+final class HelloWorld3
+{
+	public float $amount;
+	public function setAmount(mixed $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}
+
+// Dead catch: int assigned to ?float, PHP coerces int to float without TypeError
+final class FloatNullCoercion
+{
+	public ?float $amount;
+	public function setAmount(int $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) { // error: Dead catch - TypeError is never thrown in the try block.
+			echo "caught";
+		}
+	}
+}
+
+// Not dead: int|string assigned to int, string part could throw TypeError
+final class PartialTypeMatch
+{
+	public int $number;
+	/** @param int|string $value */
+	public function setNumber($value): void
+	{
+		try {
+			$this->number = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}
+
+final class MixedWillNotThrow
+{
+	public mixed $name;
+	public function setName(mixed $value): void
+	{
+		try {
+			$this->name = $value;
+		} catch (\TypeError $e) {
+			throw new \InvalidArgumentException('Expected string');
+		}
+	}
+}
+
+final class IntDoesNotAcceptFloat
+{
+	public int $amount;
+	public function setAmount(float $value): void
+	{
+		try {
+			$this->amount = $value;
+		} catch (\TypeError $e) {
+			echo "caught";
+		}
+	}
+}