YieldValue mutator does not generate any mutations

[maks-rafalko]

Question	Answer
Infection version	0.19.0, master
Test Framework version	PHPUnit
PHP version	7.4
Platform	-

See https://infection-php.dev/r/4r6

Introduced in #1342

[sanmai]

There's something wrong with the playground:

[mutators] The property YieldValue is not defined and the definition does not allow additional properties

[maks-rafalko]

it's in progress, I've updated JSON schema locally, but it still does not work when I add it explicitly

{
    "mutators": {
        "@default": true,
        "YieldValue": true
    }
}

[sanmai]

$ php vendor/bin/infection --version
Infection - PHP Mutation Testing Framework version 0.19.0@e28e9ed25217dd8a9f5ffb480347ba96e3a39d3f

$ grep -A2 mutators infection.json.dist
    "mutators": {
        "YieldValue": true
    },

And then:

$ php vendor/bin/infection -j2

Processing source code files: 4/4
.: killed, M: escaped, U: uncovered, E: fatal error, T: timed out, S: skipped

..                                                   (2 / 2)

2 mutations were generated:
       2 mutants were killed

It does generate mutants as far as I can see, not for the very this example though.

[maks-rafalko]

I took this example from tests :)

$a = function () {
    (yield $a => $b);
};

so this is still an issue

[sanmai]

Well, I can't reproduce it no matter how I try :(

[maks-rafalko]

Reason of the bug: two different mutators mutated the same Node. Nodes must be immutable

Thanks @sanmai