x/tools/gopls: feature: offer a quickfix to define a struct field on "has no field or method" error

[dennypenta]

gopls version

v0.16.2

go env

-

What did you do?

Having a cursor on a non defined field doesn't suggest a quickfix to declare a new struct field.
Recently a similar feature was merged #69692 to define a missing method.
However, the ability to make a field is missing.

What did you see happen?

no action suggested

What did you expect to see?

A suggested quick fix "Define a struct field" exists and create a field

Editor and settings

Logs

[gabyhelp]

Related Issues and Documentation

• x/tools/gopls: handle undefined struct type in `undeclaredname` autofix code action #69947
• x/tools/gopls: feature: offer quickfix for variable name that is incorrectly initialized #69980
• x/tools/gopls: multiple "Fill anonymous struct" quick fixes are confusing #48563 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[adonovan]

Sure, that seems like a reasonable feature.

[dennypenta]

great, I will start the implementation taking the issue I mentioned into account as an example.
I didn't investigate the codebase deep enough, but the plan is the following:

• I handle the same message "has no field or method"
• define a struct field info and pass this message to the code action
• define a fixer and apply it

I couldn't find a similar GetCallStubInfo for structs, if Im just seeking poorly pls let me know

[xzbdmw]

I handle the same message "has no field or method"

There is probably another case to consider:

f := Foo{
    a: 3, // unknown field a in struct literal of type Foo
}

This can be one more case for TypesFromContext, I've add
more in golang/tools#538, maybe you can
take a look.

[dennypenta]

@xzbdmw thanks, would be useful to extract the type properly.
I will rebase on your branch then.
I anticipate we should create another issue for unknown field, will do as soon as finish with this, because half of the solution can be reused.

[xzbdmw]

@dennypenta You don’t need to rebase! I will rebase on yours if your cl merge first :)