public_member_api_docs quickfix for primary constructor "this;" insertion

[navaronbracke]

This is a follow up to #64316

As of today the public_member_api_docs lint flags a primary constructor that does not have documentation.

There are two cases where it gets ambiguous:

1. There is no this; declaration: The lint flags the line where the class is declared, i.e. class Foo( {, but then it is not obvious because there are class docs above it.
2. There is a this; declaration, without a doc comment above it. The lint flags the line where the class is declared, i.e. class Foo( { and the this; declaration. Here you get two lint warnings, but the one on class Foo( { is the same ambiguity as noted above.

The quickfixes that I get today are:

• ignores for the lint (line, file, analisys_options file; not very helpful)
• convert to in-body constructor (unrelated)
• add a name to the constructor (unrelated)

But nothing suggests adding this;.

I suggest a two fold fix:

• New Quickfix: If there is no this;, then add it, which should move the linted line to the this; declaration (which still doesn't fix the lint, but now the warning is more clear)
• Make it less ambiguous: If there is a this;, then lint only on that, instead of the primary constructor itself, since the warning is really about the this; missing a doc comment, and not the Foo() {

cc @bwilkerson @FMorschel

Dart SDK version: 3.13.3 (stable) (Tue Sep 1 01:07:17 2026 -0700) on "windows_x64"

[bwilkerson]

I like both of those suggestions and I'll add one more.

I noticed that the message reads "Missing documentation for a public member.", which isn't helpful in the case where a single site is used to declare two members, such as a class name also representing the primary constructor, or a declaring parameter also declaring a field. It would be good if the message included the kind of member being referenced ('constructor', 'field', etc.) in place of the generic 'member'.