Mark internal classes and functions as @internal

[36degrees]

What

Annotate all of our 'internal' classes or functions (like the I18n class and the mergeConfigs function) as @internal.

Remove any other access annotations (like @private) from classes and functions. (Individual properties within an @internal class can still be marked as private)

Why

This is part of our decision to reset the public JavaScript API.

When using access related annotations we want to be clearer about whether the annotation refers to:

• access in context of the class – whether a particular method can be called from outside the class, including by other classes in GOV.UK Frontend
• access in context of the library – whether a particular method is considered to be available for use outside of GOV.UK Frontend

Using @private, @protected and @public only for describing class-level access helps with this.

We can then use @internal (and potentially in the future the other release tags) for library level access annotations.

Who needs to work on this

Developers

Who needs to review this

Developers

Done when

• All 'internal' classes and functions are marked as @internal
• Other access annotations are removed from the class JSDoc and any internal functions

[colinrotherham]

Related PR (and commit) regarding comment removal for @internal etc

• Configure Babel to remove non-public comments #3958

[colinrotherham]

Split out into:

• Mark internal classes and functions as @internal #4060