[rustdoc] Fix handling of stripped enum variant in JSON output format

[GuillaumeGomez]

Fixes #100529.

cc @aDotInTheVoid @Enselic
r? @notriddle

[aDotInTheVoid]

This doesn't test that the field was hidden, as

// @has enum_variant_hidden.json "$.index[*][?(@.name=='ParseError')]"
// @has enum_variant_hidden.json "$.index[*][?(@.name=='UnexpectedEndTag')]"
// @!has enum_variant_hidden.json "$.index[*][?(@.name=='u32')]"

pub enum ParseError {
    UnexpectedEndTag(u32),
}

will also pass the test.

Primitives arn't stored in the index, but in a varient of Type, so the output of the above is

    "inner": {
        "variant_inner": [
          {"inner": "u32", "kind": "primitive"}
        ],
        "variant_kind": "tuple"
      },

Instead, just directly check that the variant doesn't list having any fields.

Suggested change

	// @!has enum_variant_hidden.json "$.index[*][?(@.name=='u32')]"
	// @is - "$.index[*][?(@.name=='UnexpectedEndTag')].inner.variant_kind" '"tuple"'
	// @is - "$.index[*][?(@.name=='UnexpectedEndTag')].inner.variant_inner" []

[GuillaumeGomez]

Thanks for the suggestion!

[aDotInTheVoid]

At some point their should also be a has_striped_fields for Variant, and probably a way to tell what position each of the non stripped items are, as currently each of these 3 variants are documented with the same inner.

enum Foo {
  A(i32)
  B(i32, #[doc(hidden)] i32)
  C(#[doc(hidden)] i32, i32)
}

but HTML gets a good representation:

The solution is probably to do what we do for structs, and store the StructType, and a Vec<Id>, such that each field of a varient gets an Item to hold the name. We also should have a num_fields, as even in that schema, you can't tell the difference between

enum Foo {
  A(#[doc(hidden)] i32),
  B(#[doc(hidden)]i32, #[doc(hidden)]i32)
}

This also effects struct AFAIKT.

I don't think this needs to be done now. I'll file an issue for it.

[GuillaumeGomez]

It makes sense. Let's do it in another PR as you suggested then (and thanks for opening the issue!).

[aDotInTheVoid]

Some stylistic nitpicks (feel free to ignore)

• I don't find it's worth using #![no_std], as it doesnt remove enought to make inspecing the output plesent. (wc -c for empty rust file: 371,664 for nothing, 97,448 for #[no_std], 478 for #![no_core]`
• For json, only the first selection needs to use a the path to a json file, the rest can just use - (Also, we should change jsondocck to know the name of the json file)
• A link to the issue would be convenient for future reference.

[GuillaumeGomez]

All very good points. I'll apply them all. Can you open an issue for jsondocck improvement idea please?

[GuillaumeGomez]

Applied your comments. :)

[notriddle]

@bors r+

[bors]

📌 Commit 36758a2 has been approved by notriddle

It is now in the queue for this repository.

[GuillaumeGomez]

@bors r=aDotInTheVoid

[bors]

💡 This pull request was already approved, no need to approve it again.

• There's another pull request that is currently being tested, blocking this pull request: Rollup of 10 pull requests #100595

[bors]

📌 Commit 36758a2 has been approved by aDotInTheVoid

It is now in the queue for this repository.

[GuillaumeGomez]

Woups, the update didn't appear until I commented. Sorry.