Typing inaccuracies does not allow for configureFonts to be used with MD2 under TypeScript 5.0

[NightScript370]

Current behaviour

configureFonts's typings does not calculate isV3 correctly, meaning that it will fail with any Material Design 2 configuration

Expected behaviour

configureFonts should allow me to insert a Material Design 2 font configuration if the isV3 flag is set correctly

How to reproduce?

1. Copy the code from the documentation
2. Paste it into a brand new file anywhere with the codebase, as long as the dependencies can be found
3. Remove the third line; ./src/App is not a guaranteed file and very much example exclusive
4. Remove the export default lines at the bottom; we're trying to find type errors.

Congrats; we now have documentation-sourced code that crashes on us.

Preview

Underlined under config:

No overload matches this call.
The last overload gave the following error.
Type '{ web: { regular: { fontFamily: string; fontWeight: string; }; medium: { fontFamily: string; fontWeight: string; }; light: { fontFamily: string; fontWeight: string; }; thin: { fontFamily: string; fontWeight: string; }; }; ios: { ...; }; android: { ...; }; }' is not assignable to type 'Record<string, MD3Type>'.
Property 'web' is incompatible with index signature.
Type '{ regular: { fontFamily: string; fontWeight: string; }; medium: { fontFamily: string; fontWeight: string; }; light: { fontFamily: string; fontWeight: string; }; thin: { fontFamily: string; fontWeight: string; }; }' is missing the following properties from type 'MD3Type': fontFamily, letterSpacing, fontWeight, lineHeight, fontSize
Type 'false' is not assignable to type 'true'.ts(2769)
fonts.d.ts(78, 5): The expected type comes from property 'config' which is declared here on type '{ config: Record<string, MD3Type>; isV3?: true | undefined; }'
fonts.d.ts(77, 25): The last overload is declared here.

Underlined under isV3:

No overload matches this call.
The last overload gave the following error.
Type '{ web: { regular: { fontFamily: string; fontWeight: string; }; medium: { fontFamily: string; fontWeight: string; }; light: { fontFamily: string; fontWeight: string; }; thin: { fontFamily: string; fontWeight: string; }; }; ios: { ...; }; android: { ...; }; }' is not assignable to type 'Record<string, MD3Type>'.
Property 'web' is incompatible with index signature.
Type '{ regular: { fontFamily: string; fontWeight: string; }; medium: { fontFamily: string; fontWeight: string; }; light: { fontFamily: string; fontWeight: string; }; thin: { fontFamily: string; fontWeight: string; }; }' is missing the following properties from type 'MD3Type': fontFamily, letterSpacing, fontWeight, lineHeight, fontSize
Type 'false' is not assignable to type 'true'.ts(2769)
fonts.d.ts(79, 5): The expected type comes from property 'isV3' which is declared here on type '{ config: Record<string, MD3Type>; isV3?: true | undefined; }'
fonts.d.ts(77, 25): The last overload is declared here.

What have you tried so far?

Use official code from the people who provided the service; that proved the same thing.

Your Environment

The standard-table is non-applicable for this instance. Since this is a type error, I am using VSCodium 1.76.2's Intellisense under TypeScript 5.0.2

[DimitarNestorov]

Thanks for reporting this issue! I was able to reproduce the error and what worked for me was adding as const after the fontConfig object definition:

      thin: {
        fontFamily: 'sans-serif-thin',
        fontWeight: 'normal',
      },
    }
- };
+ } as const;
  
  const theme = {

Can you let us know if this works for you too?

[billomore]

@lukewalczak worked for me, thanks. Happened to me while running the example from this doc (full copypaste)

[rmargolinross]

This solution does not seem to work any more.