I'm not sure if this code will get attributes starting with a # and with a _. Those two ways, are common in javascript to declare an attribute as private.

This suggestion implies also to methods.

We decided in the agreement that all private attributes will be defined by #, as it is the native way to define private attributes in the latest versions of ECMAScript.

I'm not sure if the condition is well, it's intentionally with one | or should it be ||?

This is a good approach and this rule will cover a lot of cases, but it will not check classes without names but under the correct place (valueObjects or entities folders).

To achieve that, with the lines below, you can check if the file is inside those folders and run this rule inside them too.

    const filePath = context.getFilename()
    const relativePath = path.relative(context.getCwd(), filePath)

    // Check if the file is inside the requierd folders (entities, services, repositories, ...)
    const entitiesPattern = /entities|Entities/i
    const isEntityPath = entitiesPattern.test(relativePath)

    // ... same with value objects

See this PR lines, and follow the code to understand.

I suggest you detect different cases in our code base and run it there to see if this rule is working fine in different scenarios.