Dev Analyzer: "Anonymous Class" naming and visibility rules

[paulirwin]

Is there an existing issue for this?

• I have searched the existing issues

Task description

We should add dev analyzer rules to help contributors catch issues around classes that were anonymous classes in Java in our codebase.

1. Per our project naming conventions, the type name should end in "AnonymousClass", optionally followed by one or more digits. i.e. ThreadAnonymousClass, ThreadAnonymousClass1, and ThreadAnonymousClass123 are all valid, but AnonymousClassThread and ThreadAnonymousClassForSomeTest are not valid.
2. The type should be private and sealed (unless there is some good reason otherwise which could be suppressed).
3. All fields on this type should be private.

These rules should fire if "AnonymousClass" appears anywhere in the type name.

(Another option, and could be broken out separately: we could also have a custom attribute that indicates that it maps to an anonymous class in Java. This would help us apply extra scrutiny in analysis to these types, and might even let us drop the conventional name suffix at a later time if we wanted.)

Related: #666, #715

[NightOwl888]

Per our project naming conventions, the type name should end in "AnonymousClass".

I guess we should qualify this rule. When I scanned the codebase there are many classes that are named like ThreadAnonymousClass1 and ThreadAnonymousClass2 because not enough imagination was given to add a prefix to each one. So, we should probably allow a positive integer at the end of the name rather than going through and giving each class a unique prefix. Some of these went into 2 digits.