TS2379 error it @codemirror/language

v6
1

In an effort to tighten up my own coding practices, I have enabled exactOptionalPropertyTypes for the TypeScript compiler. In setting up CodeMirror extensions, I have the following:

private readonly _extensions: Extension[] = [
    // ...
    syntaxHighlighting(defaultHighlightStyle, {
        fallback: true
    }),
    //...
];

That generates the following error:

TS2379: Argument of type HighlightStyle is not assignable to parameter of type Highlighter with ‘exactOptionalPropertyTypes: true’. Consider adding undefined to the types of the target’s properties.
Types of property scope are incompatible.
Type ((type: NodeType) => boolean) | undefined is not assignable to type (node: NodeType) => boolean
Type undefined is not assignable to type (node: NodeType) => boolean

I can work around it with defaultHighlightStyle as Omit<HighlightStyle, "scope">, but I thought it best to raise it here.

2

I think this patch should help, by moving the strict-optional violation into the library, code in way that it isn’t visible anymore in the external types.

3

That looks like it would solve it, thanks. Any ETA on when it will be available via NPM?

4

There’s a @codemirror/language 6.10.3 tagged now.