JS Bundle size increased significantly since upgrade to 2.9.4 (~25k page site)

Summary

We have recently upgraded Gatsby from v2.3.4 to v2.9.4. We have since noticed a dramatic increase in the app[content-hash].js file size, it has gone from ~650kb to 3.1mb. After close inspection it is due to a massive array containing objects of matchPath data:

{
   path: "/path/example",
   matchPath: "/path/example/*"
}

Is there a reason why this data is now built to the bundle app.js file now? On the previous version we don’t get anything like this in the bundled js.

Relevant information

• Our site contains ~25k pages, each with a matchPath set for dynamic routing.
• We have static sub-router entry points for a large majority of these pages, as in our Router sits in the template passed to createPage.

[pieh]

@ConorLindsay94 Previously it was in separate file (pages-manifest), but still was loaded eagerly.

This is not easy thing to solve. Can you provide some details on why you want to create 25k pages with matchPath instead of single one?

[ConorLindsay94]

Closing this as initial approach was incorrect with matchPath assignment.