Implements BackedEnumFromDynamicStaticMethodThrowTypeExtension

[VincentLanglet]

Closes phpstan/phpstan#13297

Currently, even doing a simple Enum::from(1) where 1 is a value valid, reports missing @throws phpdoc.

[ondrejmirtes]

I really don't want people to discourage from defensive code. I don't want to report an error when someone catches an exception because the argument type is only guarded with a PHPDoc for example.

[ondrejmirtes]

getNativeType please

[VincentLanglet]

I really don't want people to discourage from defensive code. I don't want to report an error when someone catches an exception because the argument type is only guarded with a PHPDoc for example.

If I use getNative type, it will report a lot of false-positive when using ::from, as exemple this method https://github.com/phpstan/phpstan-src/pull/4156/files#diff-45aec6a97db9e1a9901c9edd9dbe1859275e5e55b5cfd4f373f051dfe040110eR12 will require to add @throws ValueError while I don't want to because I DO trust my phpdoc, since I'm the only user of my methods.

This is the same than DynamicReturnTypeExtension which remove false from the return type of a method based on the Type (and not the nativeType) which means that an extra-safety check === false will be reported as never true.

getNativeType please

Shouldn't it be at least conditioned by treatphpdoctypesascertain ? Other way it won't remove lot of useless @throws...

Or maybe DynamicMethodThrowTypeExtension should be thought differently...
I understand that you want to allow

try {
      Enum::from($foo);
} catch (...) {}

but what I try to avoid is the error

Method Foo::bar() throws checked exception

Can't the DynamicMethodThrowTypeExtension return a "BenevolentThrowType" then ? Something like an unchecked exception or an implicit throw point ?

[VincentLanglet]

Friendly ping @ondrejmirtes

Cf my comment #4156 (comment) I dunno how to move on this PR.

If I use the nativeType as asked

• I'll get a different behavior from all the other DynamicThrowTypeExtension.
• I won't solve the fact PHPStan ask for a @throws tag on such method.

    /** @param value-of<Foo> $int */
	public function sayHello(int $int): void
	{
		Foo::from($int);
	}

Moreover I feel like writing

try {
    $enum = Enum::from($foo);
} catch (ValueError) {
    // dothings
}

is kinda weird, because it's the purpose of the method tryFrom

$enum = Enum::tryFrom($foo);
if (null === $enum) {
    // dothings
}

[VincentLanglet]

I don't think the mutant

$valueType = $scope->getType($arguments[0]->value);
-        if (!$valueType->isConstantScalarValue()->yes()) {
+        if ($valueType->isConstantScalarValue()->no()) {
             return $methodReflection->getThrowType();
         }
         $enumCases = $methodReflection->getDeclaringClass()->getEnumCases();

is relevant because the whole if could be removed since there is later a check

if (!$backingValueType->isSuperTypeOf($valueType)->yes()) {
			return $methodReflection->getThrowType();
		}

It's just an early return to reduce the computation.

[ondrejmirtes]

Hi, I don't want to move on with this because I don't want to report dead catch for the following code:

/** @param 1|2|3 $i */
public function doFoo($i): void 
{
    try { IntBackedEnum::from($i); } catch (\Throwable $t) {}
}

Defensive code is good!

[VincentLanglet]

Hi, I don't want to move on with this because I don't want to report dead catch for the following code:

/** @param 1|2|3 $i */
public function doFoo($i): void 
{
    try { IntBackedEnum::from($i); } catch (\Throwable $t) {}
}

Defensive code is good!

I feel like if you want to write this, you should write instead /** @param int $i */ and it will work the same.

I have trouble to see any difference between your example and this one
https://phpstan.org/r/2db30e08-741d-4356-97e1-363aff35c8b0

I think others DynamicMethodExtension are working with getType rather than getNativeType.