Update `Punctuated` to handle the `final_value_opt`

[kayagokalp]

Currently, if there is no trailing , after the last enum variant, the variant is completely removed from the formatted output.

Example:

contract;

enum Color {
 Red : (),
 Blue : ()
}

is formatted to

contract;

enum Color {
 Red : (),
}

[eureka-cpu]

This problem extends to attributes that don't have a comma like so:

#[storage(read)]

turns into:

#[storage()]

I've tested it, and if I add the comma back in:

#[storage(read,)]

it returns back the same line...

this may actually be a problem with sway-parse!

[eureka-cpu]

cc @canndrew & @mohammadfawaz for thoughts/suggestions

[mohammadfawaz]

Sorry just noticed that I'm mentioned here. Marking this as critical.

@eureka-cpu I'm not super familiar with how the formatter uses the parser tbh... Can you elaborate on what you think the issue with the parser is?

[eureka-cpu]

@mohammadfawaz
So when you get the inner scope of a punctuated pair there isn't an optional punctuation, it's as if it assumes there will always be punctuation. This is my interpretation since the information we are looking at from the parser is Punctuated<T, P> and not Punctuated<T, Option<P>>. @canndrew correct me if I'm mistaken here 😅

[xffxff]

I investigated it and we may need to take final_value_opt into consider when we try to get the fields of the enum during formatting, now we only consider value_separator_pairs

sway/sway-parse/src/punctuated.rs

Lines 3 to 7 in 1958617

	#[derive(Clone, Debug)]
	pub struct Punctuated<T, P> {
	pub value_separator_pairs: Vec<(T, P)>,
	pub final_value_opt: Option<Box<T>>,
	}

sway/sway-fmt-v2/src/items/item_enum.rs

Line 32 in 1958617

let type_fields = &self.fields.clone().into_inner().value_separator_pairs;

I printed the ItemEnum that parser gave us, there is a filed called Blue in final_value_opt

ItemEnum {
    visibility: None,
    enum_token: ...,
    name: ...,
    generics: None,
    where_clause_opt: None,
    fields: Braces {
        inner: Punctuated {
            value_separator_pairs: [
                (
                    TypeField {
                        name: Ident {
                            name_override_opt: None,
                            span: Span {
                                src (ptr): 0x00007fcc90000c10,
                                path: None,
                                start: 25,
                                end: 28,
                                as_str(): "Red",
                            },
                        },
                        colon_token: ColonToken {
                            span: Span {
                                src (ptr): 0x00007fcc90000c10,
                                path: None,
                                start: 29,
                                end: 30,
                                as_str(): ":",
                            },
                        },
                        ty: Tuple(
                            Parens {
                                inner: Nil,
                                span: Span {
                                    src (ptr): 0x00007fcc90000c10,
                                    path: None,
                                    start: 31,
                                    end: 33,
                                    as_str(): "()",
                                },
                            },
                        ),
                    },
                    CommaToken {
                        span: Span {
                            src (ptr): 0x00007fcc90000c10,
                            path: None,
                            start: 33,
                            end: 34,
                            as_str(): ",",
                        },
                    },
                ),
            ],
            final_value_opt: Some(
                TypeField {
                    name: Ident {
                        name_override_opt: None,
                        span: Span {
                            src (ptr): 0x00007fcc90000c10,
                            path: None,
                            start: 36,
                            end: 40,
                            as_str(): "Blue",
                        },
                    },
                    colon_token: ColonToken {
                        span: Span {
                            src (ptr): 0x00007fcc90000c10,
                            path: None,
                            start: 41,
                            end: 42,
                            as_str(): ":",
                        },
                    },
                    ty: Tuple(
                        Parens {
                            inner: Nil,
                            span: Span {
                                src (ptr): 0x00007fcc90000c10,
                                path: None,
                                start: 43,
                                end: 45,
                                as_str(): "()",
                            },
                        },
                    ),
                },
            ),
        },
        span: ...,
    },
}

[eureka-cpu]

Hey @xffxff thanks for investigating, I did take into account the final_value_opt in my generics PR here: #2110 but I wasn't sure how to go about getting any formattable information from its fields

[eureka-cpu]

Ah, I see now. I'll take another whack at it, thanks again!