1 files changed, 95 insertions, 0 deletions

diff --git a/crates/completion/src/render/enum_variant.rs b/crates/completion/src/render/enum_variant.rs
new file mode 100644
index 000000000..26cfdfeea
--- /dev/null
+++ b/crates/completion/src/render/enum_variant.rs
@@ -0,0 +1,95 @@
+use hir::{HasAttrs, HirDisplay, ModPath, StructKind};
+use itertools::Itertools;
+use test_utils::mark;
+
+use crate::{
+    item::{CompletionItem, CompletionItemKind, CompletionKind},
+    render::{builder_ext::Params, RenderContext},
+};
+
+#[derive(Debug)]
+pub(crate) struct EnumVariantRender<'a> {
+    ctx: RenderContext<'a>,
+    name: String,
+    variant: hir::EnumVariant,
+    path: Option<ModPath>,
+    qualified_name: String,
+    short_qualified_name: String,
+    variant_kind: StructKind,
+}
+
+impl<'a> EnumVariantRender<'a> {
+    pub(crate) fn new(
+        ctx: RenderContext<'a>,
+        local_name: Option<String>,
+        variant: hir::EnumVariant,
+        path: Option<ModPath>,
+    ) -> EnumVariantRender<'a> {
+        let name = local_name.unwrap_or_else(|| variant.name(ctx.db()).to_string());
+        let variant_kind = variant.kind(ctx.db());
+
+        let (qualified_name, short_qualified_name) = match &path {
+            Some(path) => {
+                let full = path.to_string();
+                let short =
+                    path.segments[path.segments.len().saturating_sub(2)..].iter().join("::");
+                (full, short)
+            }
+            None => (name.to_string(), name.to_string()),
+        };
+
+        EnumVariantRender {
+            ctx,
+            name,
+            variant,
+            path,
+            qualified_name,
+            short_qualified_name,
+            variant_kind,
+        }
+    }
+
+    pub(crate) fn render(self) -> CompletionItem {
+        let mut builder = CompletionItem::new(
+            CompletionKind::Reference,
+            self.ctx.source_range(),
+            self.qualified_name.clone(),
+        )
+        .kind(CompletionItemKind::EnumVariant)
+        .set_documentation(self.variant.docs(self.ctx.db()))
+        .set_deprecated(self.ctx.is_deprecated(self.variant))
+        .detail(self.detail());
+
+        if self.variant_kind == StructKind::Tuple {
+            mark::hit!(inserts_parens_for_tuple_enums);
+            let params = Params::Anonymous(self.variant.fields(self.ctx.db()).len());
+            builder =
+                builder.add_call_parens(self.ctx.completion, self.short_qualified_name, params);
+        } else if self.path.is_some() {
+            builder = builder.lookup_by(self.short_qualified_name);
+        }
+
+        builder.build()
+    }
+
+    fn detail(&self) -> String {
+        let detail_types = self
+            .variant
+            .fields(self.ctx.db())
+            .into_iter()
+            .map(|field| (field.name(self.ctx.db()), field.signature_ty(self.ctx.db())));
+
+        match self.variant_kind {
+            StructKind::Tuple | StructKind::Unit => format!(
+                "({})",
+                detail_types.map(|(_, t)| t.display(self.ctx.db()).to_string()).format(", ")
+            ),
+            StructKind::Record => format!(
+                "{{ {} }}",
+                detail_types
+                    .map(|(n, t)| format!("{}: {}", n, t.display(self.ctx.db()).to_string()))
+                    .format(", ")
+            ),
+        }
+    }
+}