Str::afterLast()

[m8d3]

• Laravel Version: v6.10.1
• PHP Version: 7.2

Description:

I think there is a bug in Str::afterLast().

Steps To Reproduce:

The statement Str::afterLast('----Foo','---') delivers "-Foo" instead of "Foo".

[devcircus]

Which, to me, would be correct. Explain your expectation.
It says "give me everything after the last occurrence of "---". Which in the given case, is "-Foo"

[m8d3]

strpos 0: -
strpos 1: -
strpos 2: -
strpos 3: -
strpos 4: F
strpos 5: o
strpos 6: o

My expectation is, that the last occurrence of "---" is at strpos 1-3. So the Result has to be "Foo".

[Miguel-Serejo]

This does indeed look odd.

I would expect Str::afterLast($subject, $search) to be the equivalent of substr($string, strrpos($string, $search) + strlen($search)). Instead, it explodes the string by search and then returns the last part.

This is only a problem when the search string is only one character and there is a sequence of the same character in the subject string of a length that is not a multiple of the search string's length.

[driesvints]

This works as expected.

[devcircus]

Definitely see the issue now upon further inspection. 🤷🏻‍♂️

[m8d3]

@driesvints Could you please explain, why the last occurrence of "---" is not at strpos 1-3?

[driesvints]

Hmm, you're indeed correct. I misread this. Wondering what's causing this.

[Miguel-Serejo]

I tried to explain the cause in my first post.

The current implementation explodes the string using the search string as a delimiter. This works fine for almost all cases.

It only breaks when the search string is a sequence of the same character and there is a sequence of that character of length greater than the search string and not a multiple of the length of the search string, because the string explodes on the first occurrence of the search string. ----Foo explodes into [ '', '-Foo'].

For the example being used here, the search string -- would work fine, because the length of the sequence ---- in ----Foo is a multiple of the length of --.

If we want to fix this edge case, Str::last could just return substr($string, strrpos($string, $search) + strlen($search)). I don't know the performance impact.

[driesvints]

I tried substr($string, strrpos($string, $search) + strlen($search)) but that breaks some of the other use cases unfortunately.

[driesvints]

I've sent in a fix for this. Thanks for reporting 👍