Hash completion items to properly match them during /resolve

crates/ide-completion/src/item.rs

@@ -346,8 +346,7 @@ pub enum CompletionItemKind {
 impl_from!(SymbolKind for CompletionItemKind);
 
 impl CompletionItemKind {
-    #[cfg(test)]
-    pub(crate) fn tag(self) -> &'static str {
+    pub fn tag(self) -> &'static str {
         match self {
             CompletionItemKind::SymbolKind(kind) => match kind {
                 SymbolKind::Attribute => "at",

crates/ide-completion/src/lib.rs

@@ -34,6 +34,7 @@ pub use crate::{
     config::{CallableSnippets, CompletionConfig},
     item::{
         CompletionItem, CompletionItemKind, CompletionRelevance, CompletionRelevancePostfixMatch,
+        CompletionRelevanceReturnType, CompletionRelevanceTypeMatch,
     },
     snippet::{Snippet, SnippetScope},
 };

crates/rust-analyzer/Cargo.toml

@@ -21,9 +21,11 @@ path = "src/bin/main.rs"
 
 [dependencies]
 anyhow.workspace = true
+base64 = "0.22"
 crossbeam-channel.workspace = true
 dirs = "5.0.1"
 dissimilar.workspace = true
+ide-completion.workspace = true
 itertools.workspace = true
 scip = "0.5.1"
 lsp-types = { version = "=0.95.0", features = ["proposed"] }
@@ -34,6 +36,7 @@ rayon.workspace = true
 rustc-hash.workspace = true
 serde_json = { workspace = true, features = ["preserve_order"] }
 serde.workspace = true
+tenthash = "0.4.0"
 num_cpus = "1.15.0"
 mimalloc = { version = "0.1.30", default-features = false, optional = true }
 lsp-server.workspace = true

crates/rust-analyzer/src/config.rs

@@ -1440,7 +1440,7 @@ impl Config {
             limit: self.completion_limit(source_root).to_owned(),
             enable_term_search: self.completion_termSearch_enable(source_root).to_owned(),
             term_search_fuel: self.completion_termSearch_fuel(source_root).to_owned() as u64,
-            fields_to_resolve: if self.client_is_helix() || self.client_is_neovim() {
+            fields_to_resolve: if self.client_is_neovim() {
                 CompletionFieldsToResolve::empty()
             } else {
                 CompletionFieldsToResolve::from_client_capabilities(&client_capability_fields)

crates/rust-analyzer/src/handlers/request.rs

@@ -10,6 +10,7 @@ use std::{
 
 use anyhow::Context;
 
+use base64::{prelude::BASE64_STANDARD, Engine};
 use ide::{
     AnnotationConfig, AssistKind, AssistResolveStrategy, Cancellable, CompletionFieldsToResolve,
     FilePosition, FileRange, HoverAction, HoverGotoTypeData, InlayFieldsToResolve, Query,
@@ -36,6 +37,7 @@ use triomphe::Arc;
 use vfs::{AbsPath, AbsPathBuf, FileId, VfsPath};
 
 use crate::{
+    completion_item_hash,
     config::{Config, RustfmtConfig, WorkspaceSymbolConfig},
     diagnostics::convert_diagnostic,
     global_state::{FetchWorkspaceRequest, GlobalState, GlobalStateSnapshot},
@@ -1127,30 +1129,39 @@ pub(crate) fn handle_completion_resolve(
     forced_resolve_completions_config.fields_to_resolve = CompletionFieldsToResolve::empty();
 
     let position = FilePosition { file_id, offset };
-    let Some(resolved_completions) = snap.analysis.completions(
+    let Some(completions) = snap.analysis.completions(
         &forced_resolve_completions_config,
         position,
         resolve_data.trigger_character,
     )?
     else {
         return Ok(original_completion);
     };
+    let Ok(resolve_data_hash) = BASE64_STANDARD.decode(resolve_data.hash) else {
+        return Ok(original_completion);
+    };
+
+    let Some(corresponding_completion) = completions.into_iter().find(|completion_item| {
+        // Avoid computing hashes for items that obviously do not match
+        // r-a might append a detail-based suffix to the label, so we cannot check for equality
+        original_completion.label.starts_with(completion_item.label.as_str())
+            && resolve_data_hash == completion_item_hash(completion_item, resolve_data.for_ref)
+    }) else {
+        return Ok(original_completion);
+    };
+
     let mut resolved_completions = to_proto::completion_items(
         &snap.config,
         &forced_resolve_completions_config.fields_to_resolve,
         &line_index,
         snap.file_version(position.file_id),
         resolve_data.position,
         resolve_data.trigger_character,
-        resolved_completions,
+        vec![corresponding_completion],
     );
-
-    let mut resolved_completion =
-        if resolved_completions.get(resolve_data.completion_item_index).is_some() {
-            resolved_completions.swap_remove(resolve_data.completion_item_index)
-        } else {
-            return Ok(original_completion);
-        };
+    let Some(mut resolved_completion) = resolved_completions.pop() else {
+        return Ok(original_completion);
+    };
 
     if !resolve_data.imports.is_empty() {
         let additional_edits = snap

crates/rust-analyzer/src/lib.rs

@@ -47,7 +47,9 @@ use self::lsp::ext as lsp_ext;
 #[cfg(test)]
 mod integrated_benchmarks;
 
+use ide::{CompletionItem, CompletionRelevance};
 use serde::de::DeserializeOwned;
+use tenthash::TentHasher;
 
 pub use crate::{
     lsp::capabilities::server_capabilities, main_loop::main_loop, reload::ws_to_crate_graph,
@@ -61,3 +63,79 @@ pub fn from_json<T: DeserializeOwned>(
     serde_json::from_value(json.clone())
         .map_err(|e| anyhow::format_err!("Failed to deserialize {what}: {e}; {json}"))
 }
+
+fn completion_item_hash(item: &CompletionItem, is_ref_completion: bool) -> [u8; 20] {
+    fn hash_completion_relevance(hasher: &mut TentHasher, relevance: &CompletionRelevance) {
+        use ide_completion::{
+            CompletionRelevancePostfixMatch, CompletionRelevanceReturnType,
+            CompletionRelevanceTypeMatch,
+        };
+
+        hasher.update([
+            u8::from(relevance.exact_name_match),
+            u8::from(relevance.is_local),
+            u8::from(relevance.is_name_already_imported),
+            u8::from(relevance.requires_import),
+            u8::from(relevance.is_private_editable),
+        ]);
+        if let Some(type_match) = &relevance.type_match {
+            let label = match type_match {
+                CompletionRelevanceTypeMatch::CouldUnify => "could_unify",
+                CompletionRelevanceTypeMatch::Exact => "exact",
+            };
+            hasher.update(label);
+        }
+        if let Some(trait_) = &relevance.trait_ {
+            hasher.update([u8::from(trait_.is_op_method), u8::from(trait_.notable_trait)]);
+        }
+        if let Some(postfix_match) = &relevance.postfix_match {
+            let label = match postfix_match {
+                CompletionRelevancePostfixMatch::NonExact => "non_exact",
+                CompletionRelevancePostfixMatch::Exact => "exact",
+            };
+            hasher.update(label);
+        }
+        if let Some(function) = &relevance.function {
+            hasher.update([u8::from(function.has_params), u8::from(function.has_self_param)]);
+            let label = match function.return_type {
+                CompletionRelevanceReturnType::Other => "other",
+                CompletionRelevanceReturnType::DirectConstructor => "direct_constructor",
+                CompletionRelevanceReturnType::Constructor => "constructor",
+                CompletionRelevanceReturnType::Builder => "builder",
+            };
+            hasher.update(label);
+        }
+    }
+
+    let mut hasher = TentHasher::new();
+    hasher.update([
+        u8::from(is_ref_completion),
+        u8::from(item.is_snippet),
+        u8::from(item.deprecated),
+        u8::from(item.trigger_call_info),
+    ]);
+    hasher.update(&item.label);
+    if let Some(label_detail) = &item.label_detail {
+        hasher.update(label_detail);
+    }
+    // NB: do not hash edits or source range, as those may change between the time the client sends the resolve request
+    // and the time it receives it: some editors do allow changing the buffer between that, leading to ranges being different.
+    //
+    // Documentation hashing is skipped too, as it's a large blob to process,
+    // while not really making completion properties more unique as they are already.
+    hasher.update(item.kind.tag());
+    hasher.update(&item.lookup);
+    if let Some(detail) = &item.detail {
+        hasher.update(detail);
+    }
+    hash_completion_relevance(&mut hasher, &item.relevance);
+    if let Some((mutability, text_size)) = &item.ref_match {
+        hasher.update(mutability.as_keyword_for_ref());
+        hasher.update(u32::from(*text_size).to_le_bytes());
+    }
+    for (import_path, import_name) in &item.import_to_add {
+        hasher.update(import_path);
+        hasher.update(import_name);
+    }
+    hasher.finalize()
+}

crates/rust-analyzer/src/lsp/capabilities.rs

@@ -41,7 +41,7 @@ pub fn server_capabilities(config: &Config) -> ServerCapabilities {
         })),
         hover_provider: Some(HoverProviderCapability::Simple(true)),
         completion_provider: Some(CompletionOptions {
-            resolve_provider: if config.client_is_helix() || config.client_is_neovim() {
+            resolve_provider: if config.client_is_neovim() {
                 config.completion_item_edit_resolve().then_some(true)
             } else {
                 Some(config.caps().completions_resolve_provider())

crates/rust-analyzer/src/lsp/ext.rs

@@ -826,7 +826,8 @@ pub struct CompletionResolveData {
     pub imports: Vec<CompletionImport>,
     pub version: Option<i32>,
     pub trigger_character: Option<char>,
-    pub completion_item_index: usize,
+    pub for_ref: bool,
+    pub hash: String,
 }
 
 #[derive(Debug, Serialize, Deserialize)]

crates/rust-analyzer/src/lsp/to_proto.rs

@@ -5,6 +5,7 @@ use std::{
     sync::atomic::{AtomicU32, Ordering},
 };
 
+use base64::{prelude::BASE64_STANDARD, Engine};
 use ide::{
     Annotation, AnnotationKind, Assist, AssistKind, Cancellable, CompletionFieldsToResolve,
     CompletionItem, CompletionItemKind, CompletionRelevance, Documentation, FileId, FileRange,
@@ -21,6 +22,7 @@ use serde_json::to_value;
 use vfs::AbsPath;
 
 use crate::{
+    completion_item_hash,
     config::{CallInfoConfig, Config},
     global_state::GlobalStateSnapshot,
     line_index::{LineEndings, LineIndex, PositionEncoding},
@@ -295,7 +297,7 @@ fn completion_item(
         // non-trivial mapping here.
         let mut text_edit = None;
         let source_range = item.source_range;
-        for indel in item.text_edit {
+        for indel in &item.text_edit {
             if indel.delete.contains_range(source_range) {
                 // Extract this indel as the main edit
                 text_edit = Some(if indel.delete == source_range {
@@ -347,7 +349,7 @@ fn completion_item(
         something_to_resolve |= item.documentation.is_some();
         None
     } else {
-        item.documentation.map(documentation)
+        item.documentation.clone().map(documentation)
     };
 
     let mut lsp_item = lsp_types::CompletionItem {
@@ -371,10 +373,10 @@ fn completion_item(
         } else {
             lsp_item.label_details = Some(lsp_types::CompletionItemLabelDetails {
                 detail: item.label_detail.as_ref().map(ToString::to_string),
-                description: item.detail,
+                description: item.detail.clone(),
             });
         }
-    } else if let Some(label_detail) = item.label_detail {
+    } else if let Some(label_detail) = &item.label_detail {
         lsp_item.label.push_str(label_detail.as_str());
     }
 
@@ -383,6 +385,7 @@ fn completion_item(
     let imports =
         if config.completion(None).enable_imports_on_the_fly && !item.import_to_add.is_empty() {
             item.import_to_add
+                .clone()
                 .into_iter()
                 .map(|(import_path, import_name)| lsp_ext::CompletionImport {
                     full_import_path: import_path,
@@ -393,16 +396,15 @@ fn completion_item(
             Vec::new()
         };
     let (ref_resolve_data, resolve_data) = if something_to_resolve || !imports.is_empty() {
-        let mut item_index = acc.len();
         let ref_resolve_data = if ref_match.is_some() {
             let ref_resolve_data = lsp_ext::CompletionResolveData {
                 position: tdpp.clone(),
                 imports: Vec::new(),
                 version,
                 trigger_character: completion_trigger_character,
-                completion_item_index: item_index,
+                for_ref: true,
+                hash: BASE64_STANDARD.encode(completion_item_hash(&item, true)),
             };
-            item_index += 1;
             Some(to_value(ref_resolve_data).unwrap())
         } else {
             None
@@ -412,7 +414,8 @@ fn completion_item(
             imports,
             version,
             trigger_character: completion_trigger_character,
-            completion_item_index: item_index,
+            for_ref: false,
+            hash: BASE64_STANDARD.encode(completion_item_hash(&item, false)),
         };
         (ref_resolve_data, Some(to_value(resolve_data).unwrap()))
     } else {

docs/dev/lsp-extensions.md

@@ -1,5 +1,5 @@
 <!---
-lsp/ext.rs hash: 96f88b7a5d0080c6
+lsp/ext.rs hash: 14b7fb1309f5bb00
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue: