[CodeQuality] Add merge of 2 arrays of unnested items to array

[TomasVotruba]

-$nodes = array_merge([$declareNode], [$node]);
+$nodes = [$declareNode, $node];

[rvanlaak]

This seems to cause array_merge to get replaced by splat operators although these issues have strings as keys, causing the following error:

Cannot unpack array with string keys

e.g.

$res = array_merge($array1, $array2);

results in

$res = [...$array1, ...$array2];

How to test

docker run --rm -v $(DIR):/project -w /project jakzal/phpqa:alpine rector process src --set php74

[TomasVotruba]

What do you think would be the best solution for this rule?

[rvanlaak]

Would it be possible to more safely check whether the input arrays could possibly have string keys? If not, maybe mark the replacement as risky?

[TomasVotruba]

Could you provide test case of arrays that should be merged and arrays that should be skipped?

Better if based on real data, so we can make rule as close to reality as possible.

[rvanlaak]

I'll try diving into a reproduction scenario a bit further, because just found out that \Rector\Php74\Tests\Rector\FuncCall\ArraySpreadInsteadOfArrayMergeRector\Fixture\SkipStringKeys actually is there to verify string keys should get skipped.

[TomasVotruba]

It might be not good enough.
How does your minimal failing code look like?

[rvanlaak]

@TomasVotruba running make upgrade-php will show the change: https://github.com/rvanlaak/rector-tests

[TomasVotruba]

Could you put it into minimal code that doesn't need any dependency? It would be easier to put into test fixture.

And link it here: https://getrector.org/demo