Add Exception->getCode() return type provider

[VincentLanglet]

Close #4295

[VincentLanglet]

@orklah Seems like my return type provider is not used. Any idea why ?

[orklah]

Any idea why ?

Yeah, it's because I'm a moron 😄

MethodReturnTypes are actually registered here:

psalm/src/Psalm/Internal/Provider/MethodReturnTypeProvider.php

Line 60 in 97e6511

$this->registerClass(ClosureFromCallableReturnTypeProvider::class);

[orklah]

@weirdan This will be an important change. If you take a look at test with real projects, you'll see that phpunit for example has a lot of redundant casts now.

This is probably due to Psalm not being able to infer the exact type before, it pushed users into adding cast to please static analyzers, but now it will treat those as redundant.

I talked with @VincentLanglet about this and suggested adding this to Psalm 5, but he made a good point mentioning this PR is the equivalent of PHPStan behaviour right now and for users that like to use both, this difference makes things difficult. (they're forced to suppress everything on one analyzer or the other because behaviour is opposed)

What's your take on this? Can we release that on 4.x?

[weirdan]

If we marked the int type generated here with the from_calculation flag, casts would be allowed but not required:

psalm/src/Psalm/Internal/Analyzer/Statements/Expression/CastAnalyzer.php

Lines 71 to 75 in 33e9210

	if ($maybe_type->isInt()) {
	$valid_int_type = $maybe_type;
	if (!$maybe_type->from_calculation) {
	self::handleRedundantCast($maybe_type, $statements_analyzer, $stmt);
	}

[weirdan]

And then we could drop the flag in Psalm 5

[orklah]

Good,idea :)

@VincentLanglet can you apply the changes?

[VincentLanglet]

Done @orklah

[orklah]

Thanks!

[VincentLanglet]

Thanks!

You're welcome. Any plan for the next release ?