Percent sign in getStaticPaths params breaks astro build, throws a URI malformed error.

[finpluto]

Astro Info

Astro                    v5.1.1
Node                     v22.12.0
System                   Windows (x64)
Package Manager          pnpm
Output                   static
Adapter                  none
Integrations             none

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

No browser involved.

Describe the Bug

When creating dynamic routing under SSG mode, if the params returned by getStaticPaths() contain a percent sign (%) in any of route parameters, astro build will throw an URI malformed error.

I create a minimal reproducing example at percent-in-route-parameter-bug-reproduce. When building with astro build, it will exit with belowing log:

 generating static routes 
22:30:44 ▶ src/pages/[name].astro
22:30:44   └─ /Astro%foobar/index.htmlURI malformed

I tried to resolve this issue and found there are two decodeURI invokes during the dynamic routing pages rendering:

1. astro/packages/astro/src/core/render-context.ts

   Line 93 in ebe2aa9

   decodeURI(pathname),

2. astro/packages/astro/src/core/render/params-and-props.ts

   Line 54 in ebe2aa9

   const params = getParams(route, decodeURI(pathname));

According to the docs about params in dynamic routing, we should call decodeURI on them before returning from getStaticPaths. But this decoded parameter will be decoded for 2 more times when render pages, one happens in creating RenderContext and the other happens in getProps call from the RenderContext.render.

I searched in issues and found similar one(#7374), but it's about double URI decoding in SSR mode, not SSG mode.

What's the expected result?

astro build completes without throwing error.

Link to Minimal Reproducible Example

https://github.com/finpluto/percent-in-route-parameter-bug-reproduce

Participation

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