IncrementInteger and preg_match_all #1559

mfn · 2021-08-22T18:41:19Z

mfn
Aug 22, 2021

Hi there,

infection ~~n00b~~ newcomer here 😄

If an existing (much more complex) regex I use like this (very simplified example, no errors checks etc.):

function foo($a) {
  if (preg_match_all("/(\d)/", $a, $m)) {
    return $m[0];
  }
  return [];
}

foo("1234");

var_dump of $m in the positive if branch:

array(2) {
  [0]=>
  array(4) {
    [0]=>
    string(1) "1"
    [1]=>
    string(1) "2"
    [2]=>
    string(1) "3"
    [3]=>
    string(1) "4"
  }
  [1]=>
  array(4) {
    [0]=>
    string(1) "1"
    [1]=>
    string(1) "2"
    [2]=>
    string(1) "3"
    [3]=>
    string(1) "4"
  }
}

My problem: the IncrementInteger mutator change the code to $m[1];:

---     return $m[0];
+++     return $m[1];

But how can I "fix" this, i.e I don't see what test could cover this.

Thanks! 🙏

Answered by maks-rafalko

Aug 23, 2021

Hi, on your example, $m[0] returns 1 while $m[1] returns 2, so we can write a test that checks exact value.

If it doesn't matter which integer value is returned, then probably you can do the following:

replace return $m[0] with current($m). IncrementInteger mutator in this case won't be applied
Ignore IncrementInteger mutator in this method or even line of code. See how: https://infection.github.io/guide/how-to.html#How-to-disable-Mutators-and-profiles

View full answer

maks-rafalko · 2021-08-23T08:08:40Z

maks-rafalko
Aug 23, 2021
Maintainer

Hi, on your example, $m[0] returns 1 while $m[1] returns 2, so we can write a test that checks exact value.

If it doesn't matter which integer value is returned, then probably you can do the following:

replace return $m[0] with current($m). IncrementInteger mutator in this case won't be applied
Ignore IncrementInteger mutator in this method or even line of code. See how: https://infection.github.io/guide/how-to.html#How-to-disable-Mutators-and-profiles

1 reply

mfn Aug 23, 2021
Author

Hi, on your example, $m[0] returns 1 while $m[1] returns 2, so we can write a test that checks exact value.

Apologies I don't follow here 😅 $m[0] and $m[1] return the exact same array of 4 string (integer looking) values.
But…

2. Ignore IncrementInteger mutator in this method or even line of code

Thanks, this is what I ended up doing for now!

I'm not sure I like to use current() but I think I understand what you're trying to see. If I use a method like array_value_first it would also be safe, unless there's a mutator turning it into a fictional array_value_last or so 😅

Thank you 🙏

sanmai · 2021-08-23T09:29:19Z

sanmai
Aug 23, 2021
Collaborator

If you won't use the parentheses as in "/\d/" you won't have $m[1] and the test would fail on this change.

1 reply

mfn Aug 23, 2021
Author

Thanks, I'm ware of this behaviour.

In reality the regex is super complex and I don't dare to touch it; so I'll definitely stay with ignoring it

But thanks for pointing this out again, I'll remember this the next time and maybe can improve this then 👍

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

IncrementInteger and preg_match_all #1559

Uh oh!

{{title}}

Uh oh!

Replies: 2 comments 2 replies

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{title}}

Uh oh!

Select a reply

Uh oh!

Uh oh!

IncrementInteger and preg_match_all #1559

Uh oh!

mfn Aug 22, 2021

Replies: 2 comments · 2 replies

Uh oh!

maks-rafalko Aug 23, 2021 Maintainer

Uh oh!

mfn Aug 23, 2021 Author

Uh oh!

sanmai Aug 23, 2021 Collaborator

Uh oh!

mfn Aug 23, 2021 Author

mfn
Aug 22, 2021

Replies: 2 comments 2 replies

maks-rafalko
Aug 23, 2021
Maintainer

mfn Aug 23, 2021
Author

sanmai
Aug 23, 2021
Collaborator

mfn Aug 23, 2021
Author