bug(gatsby-plugin-fastify): Error fetching page data for /using-ssr when pagePrefix is set

[syckki]

The error happens when I use pathPrefix (e.g: /gatsby) in gatsby-config.js. I am serving SSR pages.

ERROR: Error processing /gatsby/page-data/using-ssr/page-data.json, Error fetching page data for /using-ssr: Page for "/gatsby/page-data/using-ssr/page-data.json" not found

To Reproduce

Steps to reproduce the behavior:

1. Run the following boilerplate npx gatsby new gatsby-starter-rendering-modes
2. Add the following packagesnpm install gatsby-plugin-fastify fastify
3. Set pathPrefix (e.g: /gatsby) in gatsby-config.js
4. Add the plugin plugins: [ { resolve: 'gatsby-plugin-fastify' }] in gatsby-config.js,
5. Add the script { "scripts": { "start": "gserve" } } in package.json
6. Run the command npm run start
7. The error appears in Console Tab

A quick search in the gatsby-plugin-fastify code reveals me, the reason of the error.

Use potentialPagePath instead of workingURL variable as pathName param in the getData method.

[Additionally to solve problem with trailingSlash]
Use path instead of workingURL variable as param of reverseFixedPagePath method.

Expected behavior

A quick change in the compiled code solves the problem.

Code line 56 is modified to use the variable potentialPagePath.

[Additionally to solve problem with trailingSlash]
Code line 93 is modified to use the variable path.

eureka!!!

System Info

• After running the command: yarn gatsby info --clipboard in my project directory

  System:
  OS: Windows 11 10.0.22621
  CPU: (4) x64 Apple Silicon
  Binaries:
  Node: 19.9.0 - C:\Users\JHONNY1\AppData\Local\Temp\xfs-fea441dd\node.CMD
  Yarn: 4.0.2 - C:\Users\JHONNY1\AppData\Local\Temp\xfs-fea441dd\yarn.CMD
  npm: 9.6.3 - C:\Program Files\nodejs\npm.CMD
  Languages:
  Python: 3.12.0
  Browsers:
  Edge: Chromium (119.0.2151.97)
  npmPackages:
  gatsby: 5.12.12 => 5.12.12
  gatsby-plugin-alias-imports: 1.0.5 => 1.0.5
  gatsby-plugin-fastify: 0.13.1 => 0.13.1
  gatsby-plugin-federation: 2.5.0 => 2.5.0
  gatsby-plugin-image: 3.12.3 => 3.12.3
  gatsby-plugin-manifest: 5.12.3 => 5.12.3
  gatsby-plugin-offline: 6.12.3 => 6.12.3
  gatsby-plugin-preconnect: 1.4.0 => 1.4.0
  gatsby-plugin-robots-txt: 1.8.0 => 1.8.0
  gatsby-plugin-sharp: 5.12.3 => 5.12.3
  gatsby-plugin-sitemap: 6.12.3 => 6.12.3
  gatsby-plugin-styled-components: 6.12.0 => 6.12.0
  gatsby-source-filesystem: 5.12.1 => 5.12.1
  gatsby-transformer-sharp: 5.12.3 => 5.12.3

[moonmeister]

This fix seems incorrect to me...those assets should still be served from /gatsby. Are you following the Gatsby Docs and correctly running the build with gatsby build --prefix-paths?

[syckki]

@moonmeister

Yes, I did!

I am using gatsby build --prefix-paths in order to build with prefixPath. Right now I am serving my app with that configuration and with that minimal change. I would appreciate to you that you can reproduce my issue following my instrucction.

Include the gatsby build --prefix-paths in the script, since I omite mentioned it before.

Note: in fact gatsby serve --prefix-paths has problems using SSR. And your plugin is better than gatsby serve

[moonmeister]

The many problems with gatsby serve are why this plugin exists.

Okay, I'll try to find some time to look at this.

From my current understanding your current solution shouldn't be correct, the assumption is...if you have a prefix, the non-prefixed path is probably an entirely different server and thus wouldn't be able to handle these routes.

[moonmeister]

Okay, confirmed. I understand what's happening. potentialPagePath seems like the correct move since we already have that. I'm happy to merge a PR on this if you can get that submitted.

[syckki]

Thank you for the confirmation! I agree with proceeding with "potentialPagePath". I plan to submit the Pull Request, but I'll do so after the Christmas holidays. I hope you have a wonderful holiday season with your loved ones as well. 🎄☃️

[moonmeister]

Deprecating Package. See: #495 for more info.