Enhancement: Implement UnwrapArrayReplace mutator

[localheinz]

This PR

• Adds new feature UnwrapArrayReplace mutator
• Covered by tests
• Doc PR: Enhancement: Implement UnwrapArrayReplace mutator site#78

Related to #514.

💁‍♂️ Follows the example in #513.

[maks-rafalko]

LGTM

[localheinz]

@borNfreee

I could imagine that this mutator could create as many mutations as arguments are passed to array_replace(), what do you think?

[maks-rafalko]

Do you mean this

- $d = array_replace(['a'], ['b'], ['c']);
+ $d = ['a'];
+ $d = ['b'];
+ $d = ['c'];

?

I didn't do any analyzing but this sounds good to me.

[localheinz]

@borNfreee

Exactly!

[sanmai]

So there go mutators for array_merge(), array_diff(), array_replace_recursive(),array_intersect(), array_intersect_assoc(), array_uintersect()... Many of them. I had these on my mind for some time, but implementing them now is like putting #494 back even further. And this important PR already needs some work to cover these new mutators.

But probably it is not a bad idea to update this mutator to use the current API now, rather than wait for #494. For inspiration see #500.

In a nutshell for this to work AbstractUnwrapMutator needs to be updated as such:

@@ -50,12 +50,16 @@ abstract class AbstractUnwrapMutator extends Mutator
      */
     final public function mutate(Node $node)
     {
-        return $node->args[$this->getParameterIndex()];
+        foreach ($this->getParameterIndex() as $index) {
+            if (array_key_exists($index, $node->args)) {
+                yield $node->args[$index];
+            }
+        }
     }
 
     abstract protected function getFunctionName(): string;
 
-    abstract protected function getParameterIndex(): int;
+    abstract protected function getParameterIndex(): \Generator;
 
     final protected function mutatesNode(Node $node): bool

And concrete mutators:

-    protected function getParameterIndex(): int
+    protected function getParameterIndex(): \Generator
     {
-        return 0;
+        yield 0;
     }

Seems doable, what do you think?

[localheinz]

@sanmai

Seems doable, what do you think?

Absolutely! For now I implemented it for the UnwrapArrayReplace mutator specifically, but I don't mind adjusting.

[localheinz]

@borNfreee @sanmai

What do you think about aaa1f75?

[maks-rafalko]

Awesome!

[maks-rafalko]

We should probably merge this one (after resolving conflict) and then rebase #534 to use yield

[sanmai]

There's something PHPStan did not like.

[maks-rafalko]

Thank you @localheinz

[localheinz]

Thank you, @borNfreee and @sanmai!