Astro.slots.has() wrongly returns true

[silveltman]

Astro Info

Astro                    v3.6.3
Node                     v18.17.1
System                   macOS (arm64)
Package Manager          yarn
Output                   static
Adapter                  none
Integrations             @astrojs/svelte
                         @astrojs/sitemap
                         astro-robots-txt
                         bookshop
                         unocss

If this issue only occurs in one browser, which browser is a problem?

/

Describe the Bug

Astro.slots.has('default') return true, even though the slot is empty.

my usecase:

<List {...list}>
      <Socials {socials} />
</List>

after running Astro.slots.render('default') I found out that it returns 2 empty spaces. When changing my component to the following it does work as expected:

<List {...list}> <Socials {socials} /></List>

What's the expected result?

I expect Astro to not count it as a slot if it's just empty spaces. Otherwise we would need to write very uggly code, especially when having a more nested structure. This quickly looks like this:

<Section {...section}><Segment {...segment}><List {...list}><Socials {socials} /></List></Segment></Section>

Not only is it way too hard to read, prettier actually wont allow it with the astro plugin.

Link to Minimal Reproducible Example

na

Participation

• I am willing to submit a pull request for this issue.

[florian-lefebvre]

@natemoo-re do you think it's caused by withastro/compiler#893 ?

[matthewp]

Pretty sure this is intentional, we just check that the slot exists, it hasn't rendered until you call render(). You can call render() and check for non-whitespace to do the same thing.

[matthewp]

Adding the need discussion label but I'm pretty sure this is just a known limitation of how slots are rendered.

[matthewp]

Talked about this with some others on the core team and this is indeed expected behavior, has() just says that a slot was passed. Use render() to check on its value.