Make `Named` work with nested loggers

[cmoog]

Similar to the issue with nested loggers not respecting Leveled, the same problem exists for Named.

[nhooyr]

Can you clarify here with a small example? I'm not sure how Named couldn't work with nested loggers.

The implementation is dead simple, see https://github.com/cdr/slog/blob/5519752b31c469cf4e04c220ec381eea4341f953/slog.go#L129

[cmoog]

Ah, so I'd say this is more of a confusion I have with the Make API... so this issue should probably be closed. Take the example below: what I'm really trying to do is "append" a Sink to a logger but keep the name, level, etc.

func TestNestedNamed(t *testing.T) {
	t.Parallel()

	s1 := &fakeSink{}
	s2 := &fakeSink{}

	l := slog.Make(s1).Named("s1")
	l = slog.Make(l, s2).Named("s2")

	l.Info(bg, "")

	// passes
	assert.Len(t, "s1 has 2 names", 2, s1.entries[0].LoggerNames)

	// fails
	assert.Len(t, "s2 has 2 names", 2, s2.entries[0].LoggerNames)
}

This "append" operation is essentially what func WithSentryIfEnabled(ctx context.Context, log slog.Logger, db *database.DB) slog.Logger is trying to do.

[cmoog]

Maybe something like func (l Logger) AppendSinks(sinks ...Sink) Logger would be useful.

[nhooyr]

Ah, I see what you mean.

Yea unfortunately, you have to use Make to combine all the loggers at the top level before you start using Named.

Can you do that in this case? If so, I'm thinking we forgo AppendSinks for now.