`debug.enable()` flushes enabled namespaces

[dbo]

Calling enable is disruptive to any enabled namespaces, which has changed in the recent minor version, caused by #409

$ DEBUG=foo node -e 'var dbg = require("debug"); dbg.enable("bar"); console.log(dbg.enabled("foo"))'
=> false

[geonanorch]

The new implementation allows full control (i.e. override of the original DEBUG settings), which seems desireable (even more in the context of changing this dynamically later on, see issue #433 ).
I submit that the main problem here is that public method enable() is not documented.
Actually debug lacks an API reference document – does obviously not prevent it from being appreciated and widely used, but makes integration with other tools more difficult...

[Qix-]

I disagree with @geonanorch slightly - I feel like .enable() should be able to take -* and .disable() should be able to take * in order to clear the enabled namespaces.

In fact, the default behavior if no namespaces are passed (e.g. literally debug.enable() and debug.disable() alike) should be to implicitly pass *, which would enable/disable all namespaces, respectively.

[geonanorch]

@Qix- I don't think that we disagree, your proposal for a reset makes plenty of sense!
Personally I prefer the 'no parameter provided' approach to a wildcard, i.e. .enable() rather than .enable(*), but that is cosmetic really.

[Qix-]

Well realistically both should be supported, I think.

[mblarsen]

It seems this issue is a wont-fix? @Qix- @geonanorch ?

In other words: the bug is a feature :)

The implicit and explicit * and -* seems to be a different feature/issue.

[Qix-]

@mblarsen Definitely not a wontfix, it's just a breaking change and requires a lot of work.