Rollup merge of #81500 - CraftSpider:union-kind, r=jyn514

Remove struct_type from union output

Also bumps the format number and adds a test

Rationale: It's illegal to have unions of the form `union Union(i32, f32);`, or `union Union;`. The struct_type field was recently removed from the rustdoc Union AST, at which time this field was changed to always just read "union". It makes sense to completely remove it, as it provides no information.

4 files changed, 20 insertions, 6 deletions

diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 438a8d57cc2..026d8f96dee 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -154,7 +154,7 @@ impl From<clean::ItemKind> for ItemEnum {
             }
             ImportItem(i) => ItemEnum::ImportItem(i.into()),
             StructItem(s) => ItemEnum::StructItem(s.into()),
-            UnionItem(u) => ItemEnum::StructItem(u.into()),
+            UnionItem(u) => ItemEnum::UnionItem(u.into()),
             StructFieldItem(f) => ItemEnum::StructFieldItem(f.into()),
             EnumItem(e) => ItemEnum::EnumItem(e.into()),
             VariantItem(v) => ItemEnum::VariantItem(v.into()),
@@ -205,11 +205,10 @@ impl From<clean::Struct> for Struct {
     }
 }
 
-impl From<clean::Union> for Struct {
+impl From<clean::Union> for Union {
     fn from(struct_: clean::Union) -> Self {
         let clean::Union { generics, fields, fields_stripped } = struct_;
-        Struct {
-            struct_type: StructType::Union,
+        Union {
             generics: generics.into(),
             fields_stripped,
             fields: ids(fields),
diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index a7c875fb748..876b1b56dee 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -243,7 +243,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
                     )
                 })
                 .collect(),
-            format_version: 2,
+            format_version: 3,
         };
         let mut p = self.out_path.clone();
         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 3fb2a32d5a0..083f99e4a68 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -194,6 +194,7 @@ pub enum ItemEnum {
     },
     ImportItem(Import),
 
+    UnionItem(Union),
     StructItem(Struct),
     StructFieldItem(Type),
     EnumItem(Enum),
@@ -239,6 +240,14 @@ pub struct Module {
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+pub struct Union {
+    pub generics: Generics,
+    pub fields_stripped: bool,
+    pub fields: Vec<Id>,
+    pub impls: Vec<Id>,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub struct Struct {
     pub struct_type: StructType,
     pub generics: Generics,
@@ -270,7 +279,6 @@ pub enum StructType {
     Plain,
     Tuple,
     Unit,
-    Union,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
diff --git a/src/test/rustdoc-json/unions/union.rs b/src/test/rustdoc-json/unions/union.rs
new file mode 100644
index 00000000000..ac2eb797791
--- /dev/null
+++ b/src/test/rustdoc-json/unions/union.rs
@@ -0,0 +1,7 @@
+// @has union.json "$.index[*][?(@.name=='Union')].visibility" \"public\"
+// @has - "$.index[*][?(@.name=='Union')].kind" \"union\"
+// @!has - "$.index[*][?(@.name=='Union')].inner.struct_type"
+pub union Union {
+    int: i32,
+    float: f32,
+}