lint to discourage `.new` constructor declarations?

[pq]

With constructor tear-offs, there is a "new" way to define the unnamed constructor for a class.

class A {
  A.new();
}

It's a little surprising that this is equivalent to the shorter version:

class A {
  A();
}

We might consider a lint to discourage people from using this new syntax.

See also: dart-lang/site-www#3525

[pq]

Puzzling about what such a lint would be called... Maybe:

• use_unnamed_constructors (or use_unnamed_constructors )
• use_implicit_unnamed_constructors (or implicit_unnamed_constructors)

(See dart-lang/language#1826 for some more useful context.)

/cc @bwilkerson @lrhn

[bwilkerson]

Will the lint only flag the use of .new in declarations, or will it also flag it in constructor invocations and anywhere else where it might appear but not be necessary? Seems like most people would want all these cases covered, but knowing the answer might influence the name of the lint.

[pq]

Excellent point. Yes, I think we'd want to recommend against both declarations and invocations.

Thoughts on naming?

[pq]

Maybe something prefixed w/ "unnecesary_" (like unnecessary_new and unnecessary_const).

unnecessary_named_unnamed_constructors ?

(A mouthful.)

[lrhn]

Name-wise, you could just wrap it into unnecessary_new 😁.
However, since it's still new, and the dominant style might change over time, it's probably a good idea to keep it separately selectable.
How about unnecessesary_constructor_new or unnecessary_new_name

[bwilkerson]

Or unnecessesary_constructor_name.

[pq]

Name-wise, you could just wrap it into unnecessary_new

That was my initial thought too but ultimately came to the same conclusion we should keep it separate.

Thanks for the name suggestions!

Or unnecessesary_constructor_name.

I'm leaning towards this one myself.

[lrhn]

We could also add a symmetric lint, "always_use_constructor_name", and see if someone wants to use that.
Just to not bias people before we know what they really want :)