Specifiy json_decode default return type

[herndlm]

mixed is too vague IMO, this should be fine to specify with more details, see also https://3v4l.org/hEDja
But please somebody double and triple check that I didn't miss anything here. Together with #993 this allows us to get rid of stdClass for example.

I was also hoping that it would "fix" phpstan/phpstan#7073 but apparently NonexistentOffsetInArrayDimFetchRule is not happy with scalar null coalescing access. But not sure if that's coming from that rule or somewhere else CC @rajyan

[ondrejmirtes]

I've rejected this idea in phpstan/phpstan-nette#89 (comment) and that's why I suggested to subtract from MixedType instead.

[herndlm]

I've rejected this idea in phpstan/phpstan-nette#89 (comment) and that's why I suggested to subtract from MixedType instead.

ah I see, makes sense. ok then

[herndlm]

I always forget that adding more type information / getting rid of mixed will potentially lead to more errors below level 9. I instinctively want to get rid of mixed everywhere :D

[rajyan]

@herndlm
https://phpstan.org/r/de94db92-8cac-49f9-bac4-4eb8b7e76ec8
As you mentioned, this case (not related to json_decode) can be solved, but we have to be careful that the union type doesn't contain object related type, because array access on object throws a fatal error.
We can change here

phpstan-src/src/Rules/Arrays/NonexistentOffsetInArrayDimFetchRule.php

Line 59 in 356250a

if (($scope->isInExpressionAssign($node) || $scope->isUndefinedExpressionAllowed($node)) && $isOffsetAccessible->yes()) {

like I changed in AccessPropertiesRule with additional check for object? I think.

phpstan-src/src/Rules/Properties/AccessPropertiesRule.php

Line 82 in f13c2c7

if ($type->canAccessProperties()->no() || $type->canAccessProperties()->maybe() && !$scope->isUndefinedExpressionAllowed($node)) {

It's just not fixed yet :)

[rajyan]

I'll send a pull request for it!

[herndlm]

ok sounds interesting, just don't spend too much time on the json_decode case. since mixed or mixed~stdClass is returned it might not work. but that's fine :)

[rajyan]

My assumption was not correct...
https://phpstan.org/r/ff9a5441-1529-42a3-b1f6-3b7cb318a7da
While null and string is offsetAccessible. IntegerType, FloatType, BooleanType is not.
This means that we need a little more complicated check in case of $scope->isUndefinedExpressionAllowed($node) === true

phpstan-src/src/Rules/Arrays/NonexistentOffsetInArrayDimFetchRule.php

Line 59 in 356250a

if (($scope->isInExpressionAssign($node) || $scope->isUndefinedExpressionAllowed($node)) && $isOffsetAccessible->yes()) {

I'm not gonna try it now...

[rajyan]

so, in case of $scope->isUndefinedExpressionAllowed($node) === true what we have to check is not $isOffsetAccessible->yes() but whether there is a Type that throws a fatal error on offset access even in null-coalesce scope. I will address this issue if more related issues are reported.