v3.2.0 Breaks Preview Mode?

Issue Summary

I upgraded from @sls-next/serverless-component@1.19.1-alpha.5 to @sls-next/serverless-component@v3.2.0 (as in my serverless.yml). Deployed with no other changes, and now preview mode isn’t working.

• @dphang I chose v3.2.0 to get the no-op rewrites support, also because it was a release version.

Actual behavior

Preview mode doesn’t work

Expected behavior

Preview mode works

Steps to reproduce

Use v3.2.0

Screenshots/Code/Configuration/Logs

Versions

• OS/Environment: Mac OS
• @sls-next/serverless-component version: v3.2.0
• Next.js version: 10.2.4-canary.2 (was on this version before upgrading serverless-next.js and everything worked fine.)

[J3tto]

Thanks @J3tto! Just to confirm – does that explain why it would have been working for the “base” page of the dynamic route?

@patricktyndall Correct the base page / evaluates to use the non dynamic SSR routes. As this SSG condition already had the !isPreview condition it bypass and pass to the SSR render just below it. https://github.com/serverless-nextjs/serverless-next.js/blob/800de8740980e103b4fc71b5fe6c8c5fdc2f8274/packages/libs/core/src/route/page.ts#L43

However the rest of the paths for [[...slug]] would evaluate to a dynamic route. With no check for preview bypass so it would serve the SSG version rather than the SSR version. https://github.com/serverless-nextjs/serverless-next.js/blob/800de8740980e103b4fc71b5fe6c8c5fdc2f8274/packages/libs/core/src/route/page.ts#L96

[J3tto]

After a little debugging I found the cause. See PR with fix.

When route was dynamic e.g. [[...slug]] data and page routes would return the SSG content, rather than the SSR.
Added the same && !isPreview to ensure it matches the same logic used on non dynamic routes.