Type error in main gatsby package index.d.ts: Type 'Node' is not generic

[timmywil]

Description

Not a dupe of #31135

PR #30819 is causing a type error on type checks. This is an issue with gatsby@3.6.0-next.0 and the default branch.

node_modules/gatsby/index.d.ts(746,9): error TS2315: Type 'Node' is not generic.

Specifically, this change where the Node type is treated as generic, but you can see here that it is not.

Steps to reproduce

Run a typescript type checker on packages/gatsby/index.d.ts. I noticed that the typescript checker in this repo only checks files in package src folders. It may be worth adding *.d.ts files as well, at least those in the main gatsby package to avoid errors like this in the future.

Expected result

No type error.

Actual result

node_modules/gatsby/index.d.ts(746,9): error TS2315: Type 'Node' is not generic.

Environment

  System:
    OS: Windows 10 10.0.19042
    CPU: (8) x64 Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
  Binaries:
    Node: 14.16.1 - C:\Program Files\nodejs\node.EXE
    npm: 6.14.12 - C:\Program Files\nodejs\npm.CMD
  Languages:
    Python: 2.7.15 - C:\Users\4timm\.windows-build-tools\python27\python.EXE
  Browsers:
    Edge: Spartan (44.19041.906.0), Chromium (90.0.818.51)
  npmPackages:
    gatsby: ^3.6.0-next.0 => 3.6.0-next.0 
    gatsby-link: ^3.4.0 => 3.4.0 
    gatsby-plugin-canonical-urls: ^3.4.0 => 3.4.0 
    gatsby-plugin-create-client-paths: ^3.4.0 => 3.4.0 
    gatsby-plugin-emotion: ^6.4.0 => 6.4.0 
    gatsby-plugin-feed: ^3.4.0 => 3.4.0 
    gatsby-plugin-google-analytics: ^3.4.0 => 3.4.0 
    gatsby-plugin-google-tagmanager: ^3.4.0 => 3.4.0 
    gatsby-plugin-image: ^1.4.0 => 1.4.0 
    gatsby-plugin-manifest: ^3.4.0 => 3.4.0 
    gatsby-plugin-offline: ^4.4.0 => 4.4.0 
    gatsby-plugin-optimize-svgs: ^1.0.5 => 1.0.5 
    gatsby-plugin-react-helmet: ^4.4.0 => 4.4.0 
    gatsby-plugin-react-svg: ^3.0.1 => 3.0.1 
    gatsby-plugin-remove-trailing-slashes: ^3.4.0 => 3.4.0 
    gatsby-plugin-s3: ^0.3.8 => 0.3.8 
    gatsby-plugin-sharp: ^3.4.1 => 3.4.1 
    gatsby-plugin-sitemap: ^4.0.0 => 4.0.0 
    gatsby-plugin-twitter: ^3.4.0 => 3.4.0 
    gatsby-plugin-typescript: ^3.4.0 => 3.4.0 
    gatsby-plugin-web-font-loader: ^1.0.4 => 1.0.4 
    gatsby-react-router-scroll: ^4.4.0 => 4.4.0 
    gatsby-remark-autolink-headers: ^4.1.0 => 4.1.0 
    gatsby-remark-check-links: ^2.1.0 => 2.1.0 
    gatsby-remark-copy-linked-files: ^4.1.0 => 4.1.0 
    gatsby-remark-embed-video: ^3.1.1 => 3.1.1 
    gatsby-remark-embedder: ^5.0.0 => 5.0.0 
    gatsby-remark-find-replace: ^0.3.0 => 0.3.0 
    gatsby-remark-images: ^5.1.0 => 5.1.0 
    gatsby-remark-prismjs: ^5.1.0 => 5.1.0 
    gatsby-remark-responsive-iframe: ^4.1.0 => 4.1.0 
    gatsby-remark-smartypants: ^4.1.0 => 4.1.0 
    gatsby-source-filesystem: ^3.4.0 => 3.4.0 
    gatsby-source-graphql: ^3.4.0 => 3.4.0 
    gatsby-transformer-remark: ^4.1.0 => 4.1.0 
    gatsby-transformer-sharp: ^3.4.0 => 3.4.0 

[vladar]

Makes sense to me 👍 Are you interested in putting up a PR with this change? We will gratefully merge it (make sure to tag me in the PR if you are up to it).

[timmywil]

I can do that. I assume that line would just return to an intersection: Node & TNode, rather than making the Node type generic?

[LekoArts]

Yeah, Node & TNode would be better! This was also done here: aa09e6f#diff-15724d4352562f842e4eb9df3a864711b1617ea4ebabc56c2aee4e975bca6767R1087

[LekoArts]

I'll get it fixed before the stable release

[LekoArts]

So unfortunately we won't be able to immediately run our type checking on *.d.ts files in gatsby as we're blocked by this feature request: microsoft/TypeScript#30511

The https://github.com/gatsbyjs/gatsby/blob/master/scripts/check-ts.js file picks up directories that have .ts files or a tsconfig (which gatsby has) and adds the directory to the -p flag.

Then the existing tsconfig.json decides what to do: https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/tsconfig.json

Since we have skipLibCheck in our root tsconfig this file needs to add skipLibCheck: false. However, @types/webpack v4 seems to mess up this:

So while it shows the incorrect type it also has too much other stuff in there.
For now I'll just fix the error and then see in a follow-up PR if maybe the types can be fixed with yarn resolutions.

[timmywil]

Thanks, sorry I didn't get to it. Regarding the skipLibCheck issue, check-ts could probably run a distinct sanity check on *.d.ts* without -p in a separate typescript run, but I understand if you want to wait until you can run them all together.