[Next-9.5.4] Rewrites URLs are not masked properly and instead interpolated.

[umarsenpai]

Bug report

Describe the bug

Hi, I have a rewrite in my app for rewriting a slug based url to legacy id based urls like:

{
  source: "/blog/:slug",
  destination: "/page/[authorId]/[pageId]"
},

Before Next 9.5.3, I was using router.push like this to navigate to slug based URL:

router.push(
     "/page/[authorId]/[pageId]?authorId=123&pageId=456&slug=some-blog",
     "/blog/some-blog"
)

It works fine on 9.5.3 as well.

But, after moving to 9.5.4, the above rewrite gets interpolated and the URL on browser is displayed like: /page/123/456?slug=some-blog instead of /blog/some-blog.

Is there another way to navigate to /blog/some-blog? Or is it an issue with the interpolate?

Regression PR: #16774
Line which causes this: https://github.com/vercel/next.js/pull/16774/files#diff-5eff10c96fa6858c659318492c4cf7f7R637

To Reproduce

I have created two codesandbox, one with 9.5.2 and one with 9.5.4 to show the behavior:

Next 9.5.4

1. Go to https://codesandbox.io/s/nextjs-next-forked-6nh2z
2. Click on 'Go to blog page'
3. The URL displayed is /page/123/456?slug=some-blog

Expected behavior

1. Go to https://codesandbox.io/s/nextjs-next-forked-qq1tc
2. Click on 'Go to blog page'
3. The URL displayed is /blog/some-blog

System information

• Version of Next.js: 9.5.4

[ijjk]

This doesn't seem to be expected 🤔 the rewrites feature isn't meant to map the dynamic route like this and instead should have the full URL already provided. The dynamic route interpolation is a client-side feature as shown in the docs here https://nextjs.org/docs/routing/introduction#linking-to-dynamic-paths

The above rewrite should be something like this instead:

{
  source: "/blog/:authorId/:slug",
  destination: "/page/:authorId/:slug"
},

If you're using unconventional routing like this href/as shouldn't have breaking changes as mentioned in the issue and can still be used, if I'm misunderstanding and href/as aren't working anymore this would be a bug and does need to be corrected otherwise this appears to be more a feature request.

[balazsorban44]

This issue has been automatically locked due to no recent activity. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.