tsconfig schema: disallow additional properties?

[OliverJAsh]

Area with issue?

JSON Schema

✔️ Expected Behavior

This should fail validation due to the typo: includes should be include.

tsconfig.json:

{
    "includes": ["foo.ts"]
}

❌ Actual Behavior

This does not fail validation, presumably because include is optional and includes is considered an additional property which is allowed.

Could we disallow additional properties to make it easier to catch typo mistakes like this?

YAML or JSON file that does not work.

See above.

IDE or code editor.

Visual Studio Code

Are you making a PR for this?

Yes, I will create a PR, once I understand more.

[hyperupcall]

I'm not opposed to this change. I think it's possible to keep the semantics of the existing schema with requires on all the subschemas that are a child of allOf. (the allOf and anyOf probably need to be removed to play well with additionalProperties: false. The exact same changes need to be made to the jsconfig.json schemas as well.