"Use primary constructor" does not produce a diagnostic for an empty public parameterless constructor

[JakeYallop]

Version Used: Compiler version: 4.10.0-3.24230.3 (abc35d6)

Steps to Reproduce:

public class MyClass
{
    public MyClass()
    {
    }
}

Diagnostic Id: IDE0290

Expected Behavior:
IDE0290 "Use primary constructor" diagnostic is raised.

Actual Behavior:
No diagnostic is raised.

Other notes
Just adding a parameter to the constructor:

public class MyClass
{
    public MyClass(string prop)
    {
    }
}

causes the diagnostic be raised.

[CyrusNajmabadi]

This was intentional, to avoid noisyness. An empty primary constructor doesn't really help at all, since there are no parameters to capture or assign to fields.

[CyrusNajmabadi]

Note: we can def consider this.

[JakeYallop]

Maybe a better fix for this, rather than offering to convert to a primary constructor, should just be to remove the default public parameterless constructor completely?

[CyrusNajmabadi]

Agreed.

[DoctorKrolic]

An empty primary constructor doesn't really help at all, since there are no parameters to capture or assign to fields.

If such constructor has attributes, it might be benifitial to make it a primary one. A common example pattern is an osbolete MEF import constructors in roslyn

[CyrusNajmabadi]

@DoctorKrolic i like that idea. let me go do that.