Server Islands does not seem to work with basepath

[sasoria]

Astro Info

Astro                    v4.13.4
Node                     v20.13.1
System                   macOS (arm64)
Package Manager          unknown
Output                   server
Adapter                  @astrojs/node
Integrations             none

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

No response

Describe the Bug

Server Islands does not seem to work when base is specified in the astro config, i.e

export default defineConfig({
  base: "/path",
  ...
});

The fetch to get the Server Island returns a 404 with the base missing a trailing slash. This happens both when I start the app with:

• npm run dev
• npm run preview

In the example above it tries to get the Server Island from: http://localhost:4321/path_server-islands/MyComponent

What's the expected result?

To fetch the Server Island correctly.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-4tmst8-5duvgl?file=astro.config.mjs

Participation

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

[sasoria]

When I go to this url: http://localhost:4321/path/_server-islands/MyComponent it returns the following error:

[matthewp]

We have tests for base actually, this is surprising. I'll take a look.

[matthewp]

Oh, it's specifically when the base doesn't contain the trailing slash. Will fix.

[matthewp]

Hm, our test is the same way. Very odd.

[matthewp]

I see, it's a combination of the base not ending with a trailing slash and trailingSlash config being set to ignore.

[sasoria]

Thank you for fixing this so fast! 🙌