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Issue Description

The default options for the@typescript-eslint/consistent-type-assertions rule are:

defaultOptions:[{assertionStyle:'as',objectLiteralTypeAssertions:'allow',},],

If a user wishes to override just theobjectLiteralTypeAssertions option to'never', but retain the defaultassertionStyle option'as', the expectation is that they could omit theassertionStyle option from their config, e.g.

"@typescript-eslint/consistent-type-assertions":["error",{objectLiteralTypeAssertions:'never',},],

Default rule options should be deeply merged with any user-supplied config, so the expected merged result would be:

{assertionStyle:'as',objectLiteralTypeAssertions:'never',},

However this results in the following error:

❯ eslintOops! Something went wrong! :(ESLint: 9.16.0Error: Key "rules": Key "@typescript-eslint/consistent-type-assertions":        Value {"objectLiteralTypeAssertions":"never"} should NOT have additional properties.                Unexpected property "objectLiteralTypeAssertions". Expected properties: "assertionStyle".        Value {"objectLiteralTypeAssertions":"never"} should have required property 'assertionStyle'.        Value {"objectLiteralTypeAssertions":"never"} should match exactly one schema in oneOf.

It would seem that the user-supplied config is completely replacing the default options instead of being merged?

Reproduction Repository Link

https://github.com/scottohara/ts-eslint-consistent-type-assertions

Repro Steps

1. clone the repo
2. npm install
3. eslint

Versions