feat(i18n): domain support

[ematipico]

Changes

Closes PLT-1317

This PR adds domain support for i18n routing.

Here's the relevant RFC: withastro/roadmap#798

Technical changes

As stated in the RFC, there are a bunch of restrictions when enabling this functionality:

• base must be set
• output must be server
• we shouldn't have pre-rendered pages

Hence, I added a bunch of errors and validation for the configuration schema

Theoretically, the Node.js adapter is the only one that would require less work to set up domains. Some work is still needed because the reserve proxy of the application needs to send the proper headers to the Node.js server, as explained in the RFC. Regardless, I preferred to mark the support as experimental.

Regarding the Vercel adapter, I decided to mark it unsupported for now, although I am open to considering "experimental" too. I want to highlight that serverless environments require more work to set multiple domains, and I am not sure if we were able to set them up from the vercel.json; for this reason I am not sure how to communicate it, and that's why I set unsupported.

Update: myself and @matthewp decided to flag the support as experimental.

Testing

I added new tests that should verify the new behaviour of the *Absolute functions.

I added new integrations tests to very that the Requests are correctly handled when we send the proper headers.

Docs

/cc @withastro/maintainers-docs for feedback!

[changeset-bot]

🦋 Changeset detected

Latest commit: 666f3e3

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[sarah11918]

Did a quick review of the changeset first! (Have not yet looked at the API docs) because I want to make sure I understand what's happening here to get the API descriptions just right!

[matthewp]

I think it's better to use the 1 arg form of new URL unless there's a reason to do it the other way that I can't think of?

[matthewp]

We're going to release this in 4.x

[sarah11918]

Thanks for your help with this one, @ematipico ! I fixed some silly formatting/typos in the changeset, but I think it's now quite good!

Had a suggestion for each of the config items. They might be a bit verbose, but we can always refine them, and once we've finalized the guide, we'll know for sure which info we want there vs here. I think these are still the minimum we might want someone to see when they're looking things up in reference, though? Let's see what we think!

[sarah11918]

OK! These update to the agreed-upon configuration set up! I'm happy with the changeset as is, but still want to fine-tune the docs entry, especially because of the experimental-ness of it. (This entry doesn't explicitly mention the experimental flag, for example and we must do that!

I'm thinking that maybe we should put the docs entry under Experimental Flags. I think that makes the most organizational sense, and would make the instruction to enable a flag, then add a domains to a pre-configured i18n site easier to include here. Being experimental, this feature might change anyway. And even if it doesn't that means editing more than just the name of this entry to update config-reference here. So I'm not convinced we save much by having it here vs experimental.

Another option could be to write this entry here as if it were NOT experimental, just not expose it to docs. Then, add a complete corresponding entry as if it IS expermental in the Experimental flags section that DOES show up in docs. When it's no longer experimental, we entirely delete the experimental entry and (making sure it's updated), then add back @docs here. (If I'm writing this once, copy and paste is free!)

Thoughts?

[sarah11918]

ALRIGHT! I am approving for the sake of completion! 🥳

If there are any syntax errors or nits, I'll find them after this is merged on Wed. and I can check and make any quick fixes well before releasing on Thursday. 🫡

Merge day

[jlarmstrongiv]

I’m getting errors, despite not using i18nDomains

19:01:17 [ERROR] [config] The feature "i18nDomains" is not supported (used by astro-sst).
19:01:17 [ERROR] The adapter astro-sst doesn't support the feature i18nDomains. Your project won't be built. You should not use it.