Avoid false inference with instanceof

[VincentLanglet]

No description provided.

[VincentLanglet]

I tried to copy the logic from MutatingScope::inferType with an uncertainty boolean:

phpstan-src/src/Analyser/MutatingScope.php

Lines 960 to 989 in adcabb3

	$classType = TypeTraverser::map($classType, static function (Type $type, callable $traverse) use (&$uncertainty): Type {
	if ($type instanceof UnionType || $type instanceof IntersectionType) {
	return $traverse($type);
	}
	if ($type->getObjectClassNames() !== []) {
	$uncertainty = true;
	return $type;
	}
	if ($type instanceof GenericClassStringType) {
	$uncertainty = true;
	return $type->getGenericType();
	}
	if ($type instanceof ConstantStringType) {
	return new ObjectType($type->getValue());
	}
	return new MixedType();
	});
	}
	if ($classType->isSuperTypeOf(new MixedType())->yes()) {
	return new BooleanType();
	}
	$isSuperType = $classType->isSuperTypeOf($expressionType);
	if ($isSuperType->no()) {
	return new ConstantBooleanType(false);
	} elseif ($isSuperType->yes() && !$uncertainty) {
	return new ConstantBooleanType(true);
	}

[VincentLanglet]

I'm unsure to say PHPStan that

• $e1 is not Throwable~LogicException but still Throwable
• the specific expression $e1 instanceof $e2 is false because already computed.

But I'm not sure it's a big loss.

[VincentLanglet]

If I call doFar($foo, $superBar) with superBar a class extending bar,
$foo is only Foo~SuperBar but can still being Bar.

[VincentLanglet]

if I pass class-string<SuperFoo> for $classString the subject will only be mixed~SuperFoo but not mixed~Foo.

[VincentLanglet]

Same idea.

[VincentLanglet]

Code is

	/**
	 * @template T of \Exception
	 * @param T $e
	 */
	public function test(\Throwable $t, $e): void {
		if ($t instanceof $e) return;
		if ($e instanceof $t) return;
	}

if I call it with test(new \Exception(), new \LogicException()) the second if is true.

[phpstan-bot]

This pull request has been marked as ready for review.