Use of `unknown` type from Typescript 3 breaks all other TypeScript versions

[matthewmeyer]

Thanks for adding Typescript type definitions but use of Typescrpt 3 features suddenly started breaking my Typescript 2.7 build.

node_modules/@types/unist/index.d.ts(31,20): error TS2304: Cannot find name 'unknown'.
node_modules/@types/unist/index.d.ts(40,20): error TS2304: Cannot find name 'unknown'.
node_modules/@types/unist/index.d.ts(97,12): error TS2304: Cannot find name 'unknown'.

[matthewmeyer]

For now I've updated my semver to "vfile-message": "1.0.2" as a workaround.

[ChristianMurphy]

Requirement of TypeScript 3+ is intended

vfile-message/types/index.d.ts

Line 1 in 1b0d298

// TypeScript Version: 3.0

There is an open discussion of TypeScript versions on Spectrum https://spectrum.chat/unified/type-definitions?thread=7c1f6266-6be2-4d0a-b599-4ff93a6d0efd
Feel free to add your perspective on why TypeScript 2 should be supported.

[rjimenezda]

@matthewmeyer I got the same issue. I was able to suppress the error adding "skipLibCheck": true to tsconfig compiler options, although I'm not sure that's the best way of addressing it.

[wooorm]

• Is there a way typescript 2 could ignore typescript 3 definitions?
• What was the v2 version of unknown, could we use that instead?

[matthewmeyer]

The v2 version of unknown would be any, but it is not an equivalent type. any allows any type whereas unknown is a bit stricter and was added to allow a but more strictness.

[matthewmeyer]

@matthewmeyer I got the same issue. I was able to suppress the error adding "skipLibCheck": true to tsconfig compiler options, although I'm not sure that's the best way of addressing it.

I could also try this in a pinch but I'n not excited about losing all that type checking :)

[mogafk]

+1 same problem

[antonpodolsky]

Please bump major version, this is a breaking change.

@type/unist now uses unknown which is supported in Typescript 3 only.
https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/unist/index.d.ts#L40

[Lukermelesh]

Suddenly breaking everyone who is using typescript <3.0.0 without a major version bump wouldn't be very nice.

[skreis]

For a little more context on how this can ruin your (my) day, I'm working within the context of a TypeScript 2.9 application with a dependency tree that looks like:

• react-markdown ^3.6.0
  • depends on unified ^6.1.5
    • depends on vfile ^2.0.0
      • depends on vfile-message ^1.0.0

[rjimenezda]

Here's mine 😅

└─┬ stylelint@9.9.0
  └─┬ postcss-markdown@0.34.0
    └─┬ remark@9.0.0
      └─┬ unified@6.2.0
        └─┬ vfile@2.3.0
          └── vfile-message@1.1.0

[sshetty]

This is mine

[wooorm]

Hey folks. Sorry about this. I don’t use typescript myself.
Would a fix be to use any instead of unknown here?