Extend statement with & selector causes crash

[bassplayer7]

I have this situation in one of my SCSS stylesheets which I'm compiling with libsass (with CodeKit 2):

At the time of writing, I didn't put it together that @extend & will always extend the current selector and as such doesn't make sense. However, CodeKit crashed with that and I'm guessing that it threw an unrecoverable exception. I suppose it is conceivable that others would make the same mistake that I did, and it would be nice to have an error saying that the "current select cannot be extended". Obviously, had it compiled or told me, I would have immediately realized the error of my thought at that moment.

[mgreter]

I can confirm that this segfaults. Fix seems simple as we just need to error when we extend '&'

Can't extend &: can't extend parent selectors

@bassplayer7 thanks for the report! I just don't understand why quite a few people actually like to post pictures of code instead of just pasting the code (it keeps us from transcribing the test case) 😕

foo {
  @extend &;
}

[bassplayer7]

@mgreter, I'm sorry about that. I absolutely should have included the code: I'm not sure why it didn't cross my mind.

---

Here's where it happened to me, in case it affects your error message:

.column {
  & {
    width: 31%;
    margin: 1rem 1.5%;
    display: inline-block;
    vertical-align: top;

    &-half {
      @extend &;
    }
  }
}

That was perhaps what made me miss the error of my way originally is that it was not extending a parent selector. I was trying to extend .column, but would have extended .column-half unintentionally. I'm not sure if that would impact the error message.

Thanks for working on this! I appreciate libsass very much.

[mgreter]

Not sure if you expect this to compile, but ruby sass gives this error (and libsass segfaults):

Error: Can't extend &: can't extend parent selectors
        on line 9 of foo.scss
  Use --trace for backtrace.

So we need add this check to libsass, but the given code is not valid sass ...

[bassplayer7]

Ok. Great. Right, I didn't expect the SCSS to compile, I was just commenting on the error message. And, & could, and often would be a parent selector, so that message would make sense. Again, I really appreciate your work on that.

[mgreter]

Ah, I guess I got you now. The error seems to repeat what you tried to extend. Ie. @extend &.xyz will lead to Can't extend &.xyz.

[mgreter]

Fix was merged and will be in 3.3

[xzyfer]

Spec added and activated in sass/sass-spec#689

[brookjordan]

Why not allow extending of parent selectors?
I was hoping this would work — I'm using B__E--M and would love for modifiers to be able to extend their parent without having to type the full parent selector out.

[xzyfer]

@brookjordan LibSass just implements the Sass language. Questions and suggestions about the language should be raised with Sass - https://github.com/sass/sass

[brookjordan]

Oops, sorry. Thanks @xzyfer !