feat(completion): reduce relevance for deprecated items

crates/ide-completion/src/context/analysis.rs

@@ -2094,12 +2094,12 @@ fn next_non_trivia_token(e: impl Into<SyntaxElement>) -> Option<SyntaxToken> {
 }
 
 fn next_non_trivia_sibling(ele: SyntaxElement) -> Option<SyntaxElement> {
-    let mut e = ele.next_sibling_or_token();
-    while let Some(inner) = e {
-        if !inner.kind().is_trivia() {
-            return Some(inner);
+    let mut e = ele;
+    while let Some(next) = e.next_sibling_or_token() {
+        if !next.kind().is_trivia() {
+            return Some(next);
         } else {
-            e = inner.next_sibling_or_token();
+            e = next;
         }
     }
     None

crates/ide-completion/src/item.rs

@@ -61,6 +61,9 @@ pub struct CompletionItem {
     pub documentation: Option<Documentation<'static>>,
 
     /// Whether this item is marked as deprecated
+    ///
+    /// NOTE: this field is used in the LSP protocol. For the use of this information in completion
+    /// scoring, see [`CompletionRelevance::is_deprecated`].
     pub deprecated: bool,
 
     /// If completing a function call, ask the editor to show parameter popup
@@ -186,6 +189,11 @@ pub struct CompletionRelevance {
     pub is_skipping_completion: bool,
     /// if inherent impl already exists in current module, user may not want to implement it again.
     pub has_local_inherent_impl: bool,
+    /// Set when the completion item is deprecated.
+    ///
+    /// NOTE: This is duplicated from [`CompletionItem::deprecated`] in order to allow using this
+    /// information in the calculation of the relevance score.
+    pub is_deprecated: bool,
 }
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub struct CompletionRelevanceTraitInfo {
@@ -278,6 +286,7 @@ impl CompletionRelevance {
             function,
             is_skipping_completion,
             has_local_inherent_impl,
+            is_deprecated,
         } = self;
 
         // only applicable for completions within use items
@@ -354,6 +363,11 @@ impl CompletionRelevance {
             score -= 5;
         }
 
+        // lower rank for deprecated items
+        if is_deprecated {
+            score -= 5;
+        }
+
         score
     }
 
@@ -582,6 +596,9 @@ impl Builder {
             None => TextEdit::replace(self.source_range, insert_text),
         };
 
+        // Copy `deprecated` to `self.relevance.is_deprecated`
+        let relevance = CompletionRelevance { is_deprecated: self.deprecated, ..self.relevance };
+
         let import_to_add = self
             .imports_to_add
             .into_iter()
@@ -603,7 +620,7 @@ impl Builder {
             kind: self.kind,
             deprecated: self.deprecated,
             trigger_call_info: self.trigger_call_info,
-            relevance: self.relevance,
+            relevance,
             ref_match: self.ref_match,
             import_to_add,
         }
@@ -674,6 +691,15 @@ impl Builder {
         self
     }
     pub(crate) fn set_relevance(&mut self, relevance: CompletionRelevance) -> &mut Builder {
+        // The default value of `CompletionRelevance.is_deprecated` is `false`, so it being `true`
+        // would mean it was set manually. Advise using the other function instead.
+        //
+        // This is technically not necessary, because `deprecated` will get reconciled in
+        // `Builder::build` anyway -- it just helps keep the callers consistent.
+        assert!(
+            !relevance.is_deprecated,
+            "`deprecated` should be set using `Builder::set_deprecated` instead"
+        );
         self.relevance = relevance;
         self
     }
@@ -708,9 +734,25 @@ mod tests {
     use test_utils::assert_eq_text;
 
     use super::{
-        CompletionRelevance, CompletionRelevancePostfixMatch, CompletionRelevanceTypeMatch,
+        CompletionItem, CompletionItemKind, CompletionRelevance, CompletionRelevancePostfixMatch,
+        CompletionRelevanceTypeMatch,
     };
 
+    #[test]
+    fn builder_deprecated_from_set_deprecated() {
+        // setting just `item.deprecated` also sets `item.relevance.is_deprecated`
+        let mut builder = CompletionItem::new(
+            CompletionItemKind::Expression,
+            Default::default(),
+            "",
+            syntax::Edition::DEFAULT,
+        );
+        builder.set_deprecated(true);
+        let item = builder.build(&Default::default());
+        assert!(item.deprecated);
+        assert!(item.relevance.is_deprecated);
+    }
+
     /// Check that these are CompletionRelevance are sorted in ascending order
     /// by their relevance score.
     ///