Add doc(alias)-based field completion

Author: hecatia-elegua

crates/ide-completion/src/completions.rs

@@ -430,8 +430,9 @@ impl Completions {
             Visible::Editable => true,
             Visible::No => return,
         };
+        let doc_aliases = ctx.doc_aliases(&field);
         let item = render_field(
-            RenderContext::new(ctx).private_editable(is_private_editable),
+            RenderContext::new(ctx).private_editable(is_private_editable).doc_aliases(doc_aliases),
             dot_access,
             receiver,
             field,

crates/ide-completion/src/context.rs

@@ -441,6 +441,14 @@ impl<'a> CompletionContext<'a> {
         self.is_visible_impl(&vis, &attrs, item.krate(self.db))
     }
 
+    pub(crate) fn doc_aliases<I>(&self, item: &I) -> Vec<SmolStr>
+    where
+        I: hir::HasAttrs + Copy,
+    {
+        let attrs = item.attrs(self.db);
+        attrs.doc_aliases().collect()
+    }
+
     /// Check if an item is `#[doc(hidden)]`.
     pub(crate) fn is_item_hidden(&self, item: &hir::ItemInNs) -> bool {
         let attrs = item.attrs(self.db);
@@ -499,7 +507,7 @@ impl<'a> CompletionContext<'a> {
             if self.is_scope_def_hidden(def) {
                 return;
             }
-            let doc_aliases = self.doc_aliases(def);
+            let doc_aliases = self.doc_aliases_in_scope(def);
             f(name, def, doc_aliases);
         });
     }
@@ -547,7 +555,7 @@ impl<'a> CompletionContext<'a> {
         self.krate != defining_crate && attrs.has_doc_hidden()
     }
 
-    fn doc_aliases(&self, scope_def: ScopeDef) -> Vec<SmolStr> {
+    fn doc_aliases_in_scope(&self, scope_def: ScopeDef) -> Vec<SmolStr> {
         if let Some(attrs) = scope_def.attrs(self.db) {
             attrs.doc_aliases().collect()
         } else {

crates/ide-completion/src/item.rs

@@ -4,6 +4,7 @@ use std::fmt;
 
 use hir::{Documentation, Mutability};
 use ide_db::{imports::import_assets::LocatedImport, SnippetCap, SymbolKind};
+use itertools::Itertools;
 use smallvec::SmallVec;
 use stdx::{impl_from, never};
 use syntax::{SmolStr, TextRange, TextSize};
@@ -353,7 +354,7 @@ impl CompletionItem {
             relevance: CompletionRelevance::default(),
             ref_match: None,
             imports_to_add: Default::default(),
-            doc_aliases: None,
+            doc_aliases: vec![],
         }
     }
 
@@ -386,7 +387,7 @@ pub(crate) struct Builder {
     source_range: TextRange,
     imports_to_add: SmallVec<[LocatedImport; 1]>,
     trait_name: Option<SmolStr>,
-    doc_aliases: Option<SmolStr>,
+    doc_aliases: Vec<SmolStr>,
     label: SmolStr,
     insert_text: Option<String>,
     is_snippet: bool,
@@ -418,7 +419,8 @@ impl Builder {
         let mut lookup = self.lookup.unwrap_or_else(|| label.clone());
         let insert_text = self.insert_text.unwrap_or_else(|| label.to_string());
 
-        if let Some(doc_aliases) = self.doc_aliases {
+        if !self.doc_aliases.is_empty() {
+            let doc_aliases = self.doc_aliases.into_iter().join(", ");
             label = SmolStr::from(format!("{label} (alias {doc_aliases})"));
             lookup = SmolStr::from(format!("{lookup} {doc_aliases}"));
         }
@@ -464,8 +466,8 @@ impl Builder {
         self.trait_name = Some(trait_name);
         self
     }
-    pub(crate) fn doc_aliases(&mut self, doc_aliases: SmolStr) -> &mut Builder {
-        self.doc_aliases = Some(doc_aliases);
+    pub(crate) fn doc_aliases(&mut self, doc_aliases: Vec<SmolStr>) -> &mut Builder {
+        self.doc_aliases = doc_aliases;
         self
     }
     pub(crate) fn insert_text(&mut self, insert_text: impl Into<String>) -> &mut Builder {

crates/ide-completion/src/render.rs

@@ -152,6 +152,7 @@ pub(crate) fn render_field(
             }
         }
     }
+    item.doc_aliases(ctx.doc_aliases);
     item.build()
 }
 
@@ -361,11 +362,7 @@ fn render_resolution_simple_(
         item.add_import(import_to_add);
     }
 
-    let doc_aliases = ctx.doc_aliases;
-    if !doc_aliases.is_empty() {
-        let doc_aliases = doc_aliases.into_iter().join(", ").into();
-        item.doc_aliases(doc_aliases);
-    }
+    item.doc_aliases(ctx.doc_aliases);
     item
 }
 

crates/ide-completion/src/tests/special.rs

@@ -1086,3 +1086,22 @@ fn here_we_go() {
         "#]],
     );
 }
+
+#[test]
+fn completes_field_name_via_doc_alias_in_fn_body() {
+    check(
+        r#"
+struct Foo {
+    #[doc(alias = "qux")]
+    bar: u8
+};
+
+fn here_we_go() {
+    let foo = Foo { q$0 }
+}
+"#,
+        expect![[r#"
+            fd bar (alias qux) u8
+        "#]],
+    );
+}