5 files changed, 120 insertions, 105 deletions

diff --git a/crates/completion/src/item.rs b/crates/completion/src/item.rs
index 0e59f73cb..dc67df075 100644
--- a/crates/completion/src/item.rs
+++ b/crates/completion/src/item.rs
@@ -12,6 +12,7 @@ use crate::config::SnippetCap;
 /// `CompletionItem` describes a single completion variant in the editor pop-up.
 /// It is basically a POD with various properties. To construct a
 /// `CompletionItem`, use `new` method and the `Builder` struct.
+#[derive(Clone)]
 pub struct CompletionItem {
     /// Used only internally in tests, to check only specific kind of
     /// completion (postfix, keyword, reference, etc).
diff --git a/crates/completion/src/test_utils.rs b/crates/completion/src/test_utils.rs
index 4c1b1a839..516a63b4d 100644
--- a/crates/completion/src/test_utils.rs
+++ b/crates/completion/src/test_utils.rs
@@ -97,6 +97,7 @@ pub(crate) fn check_edit_with_config(
         .unwrap_or_else(|| panic!("can't find {:?} completion in {:#?}", what, completions));
     let mut actual = db.file_text(position.file_id).to_string();
     completion.text_edit().apply(&mut actual);
+    // TODO kb how to apply imports now?
     assert_eq_text!(&ra_fixture_after, &actual)
 }
 
diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index ba4bf2eeb..e12651937 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -7,7 +7,7 @@ use std::{sync::Arc, time::Instant};
 
 use crossbeam_channel::{unbounded, Receiver, Sender};
 use flycheck::FlycheckHandle;
-use ide::{Analysis, AnalysisHost, Change, FileId, ImportToAdd};
+use ide::{Analysis, AnalysisHost, Change, CompletionItem, FileId};
 use ide_db::base_db::{CrateId, VfsPath};
 use lsp_types::{SemanticTokens, Url};
 use parking_lot::{Mutex, RwLock};
@@ -51,6 +51,11 @@ pub(crate) struct Handle<H, C> {
 pub(crate) type ReqHandler = fn(&mut GlobalState, lsp_server::Response);
 pub(crate) type ReqQueue = lsp_server::ReqQueue<(String, Instant), ReqHandler>;
 
+pub(crate) struct CompletionResolveData {
+    pub(crate) file_id: FileId,
+    pub(crate) item: CompletionItem,
+}
+
 /// `GlobalState` is the primary mutable state of the language server
 ///
 /// The most interesting components are `vfs`, which stores a consistent
@@ -69,7 +74,7 @@ pub(crate) struct GlobalState {
     pub(crate) config: Config,
     pub(crate) analysis_host: AnalysisHost,
     pub(crate) diagnostics: DiagnosticCollection,
-    pub(crate) additional_imports: FxHashMap<usize, ImportToAdd>,
+    pub(crate) completion_resolve_data: FxHashMap<usize, CompletionResolveData>,
     pub(crate) mem_docs: FxHashMap<VfsPath, DocumentData>,
     pub(crate) semantic_tokens_cache: Arc<Mutex<FxHashMap<Url, SemanticTokens>>>,
     pub(crate) vfs: Arc<RwLock<(vfs::Vfs, FxHashMap<FileId, LineEndings>)>>,
@@ -122,7 +127,7 @@ impl GlobalState {
             config,
             analysis_host,
             diagnostics: Default::default(),
-            additional_imports: FxHashMap::default(),
+            completion_resolve_data: FxHashMap::default(),
             mem_docs: FxHashMap::default(),
             semantic_tokens_cache: Arc::new(Default::default()),
             vfs: Arc::new(RwLock::new((vfs::Vfs::default(), FxHashMap::default()))),
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index d9fdf0434..a186d2e5d 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -5,14 +5,12 @@
 use std::{
     io::Write as _,
     process::{self, Stdio},
-    sync::Arc,
 };
 
 use ide::{
-    FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, ImportToAdd, LineIndex,
-    NavigationTarget, Query, RangeInfo, Runnable, RunnableKind, SearchScope, TextEdit,
+    FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, NavigationTarget, Query,
+    RangeInfo, Runnable, RunnableKind, SearchScope, TextEdit,
 };
-use ide_db::helpers::{insert_use, mod_path_to_ast};
 use itertools::Itertools;
 use lsp_server::ErrorCode;
 use lsp_types::{
@@ -36,10 +34,10 @@ use crate::{
     cargo_target_spec::CargoTargetSpec,
     config::RustfmtConfig,
     from_json, from_proto,
-    global_state::{GlobalState, GlobalStateSnapshot},
-    line_endings::LineEndings,
+    global_state::{CompletionResolveData, GlobalState, GlobalStateSnapshot},
     lsp_ext::{self, InlayHint, InlayHintsParams},
-    to_proto, LspError, Result,
+    to_proto::{self, append_import_edits},
+    LspError, Result,
 };
 
 pub(crate) fn handle_analyzer_status(
@@ -538,12 +536,6 @@ pub(crate) fn handle_runnables(
     Ok(res)
 }
 
-#[derive(Debug, Copy, Clone, Serialize, Deserialize)]
-pub(crate) struct ResolveCompletionData {
-    completion_id: usize,
-    completion_file_id: u32,
-}
-
 pub(crate) fn handle_completion(
     global_state: &mut GlobalState,
     params: lsp_types::CompletionParams,
@@ -579,38 +571,31 @@ pub(crate) fn handle_completion(
     };
     let line_index = snap.analysis.file_line_index(position.file_id)?;
     let line_endings = snap.file_line_endings(position.file_id);
-    let mut additional_imports = FxHashMap::default();
+    let mut completion_resolve_data = FxHashMap::default();
 
     let items: Vec<CompletionItem> = items
         .into_iter()
         .enumerate()
         .flat_map(|(item_index, item)| {
-            let resolve_completion_data = ResolveCompletionData {
-                completion_id: item_index,
-                completion_file_id: position.file_id.0,
-            };
-            let import_to_add = item.import_to_add().cloned();
-            let mut new_completion_items =
-                to_proto::completion_item(&line_index, line_endings, item);
-
-            if let Some(import_to_add) = import_to_add {
-                for new_item in &mut new_completion_items {
-                    match serde_json::to_value(&resolve_completion_data) {
-                        Ok(resolve_value) => {
-                            new_item.data = Some(resolve_value);
-                            additional_imports.insert(item_index, import_to_add.clone());
-                        }
-                        Err(e) => {
-                            log::error!("Failed to serialize completion resolve metadata: {}", e)
-                        }
-                    }
-                }
+            let mut new_completion_items = to_proto::completion_item(
+                &line_index,
+                line_endings,
+                item.clone(),
+                &snap.config.completion.resolve_capabilities,
+            );
+
+            let item_id = serde_json::to_value(&item_index)
+                .expect(&format!("Should be able to serialize usize value {}", item_index));
+            completion_resolve_data
+                .insert(item_index, CompletionResolveData { file_id: position.file_id, item });
+            for new_item in &mut new_completion_items {
+                new_item.data = Some(item_id.clone());
             }
             new_completion_items
         })
         .collect();
 
-    global_state.additional_imports = additional_imports;
+    global_state.completion_resolve_data = completion_resolve_data;
 
     let completion_list = lsp_types::CompletionList { is_incomplete: true, items };
     Ok(Some(completion_list.into()))
@@ -622,71 +607,38 @@ pub(crate) fn handle_resolve_completion(
 ) -> Result<lsp_types::CompletionItem> {
     let _p = profile::span("handle_resolve_completion");
 
-    match original_completion.data.as_ref() {
-        Some(completion_data) => {
-            match serde_json::from_value::<ResolveCompletionData>(completion_data.clone()) {
-                Ok(resolve_completion_data) => {
-                    if let Some(import_to_add) =
-                        global_state.additional_imports.get(&resolve_completion_data.completion_id)
-                    {
-                        let snap = global_state.snapshot();
-                        let file_id = FileId(resolve_completion_data.completion_file_id);
-                        let line_index = snap.analysis.file_line_index(file_id)?;
-                        let line_endings = snap.file_line_endings(file_id);
-
-                        let resolved_edits =
-                            resolve_additional_edits(import_to_add, line_index, line_endings);
-
-                        original_completion.additional_text_edits =
-                            match original_completion.additional_text_edits {
-                                Some(mut original_additional_edits) => {
-                                    if let Some(mut new_edits) = resolved_edits {
-                                        original_additional_edits.extend(new_edits.drain(..))
-                                    }
-                                    Some(original_additional_edits)
-                                }
-                                None => resolved_edits,
-                            };
-                    } else {
-                        log::error!(
-                            "Got no import data for completion with label {}, id {}",
-                            original_completion.label,
-                            resolve_completion_data.completion_id
-                        )
-                    }
+    let server_completion_data = match original_completion
+        .data
+        .as_ref()
+        .map(|data| serde_json::from_value::<usize>(data.clone()))
+        .transpose()?
+        .and_then(|server_completion_id| {
+            global_state.completion_resolve_data.get(&server_completion_id)
+        }) {
+        Some(data) => data,
+        None => return Ok(original_completion),
+    };
+
+    let snap = &global_state.snapshot();
+    for supported_completion_resolve_cap in &snap.config.completion.resolve_capabilities {
+        match supported_completion_resolve_cap {
+            ide::CompletionResolveCapability::AdditionalTextEdits => {
+                // TODO kb actually add all additional edits here?
+                if let Some(import_to_add) = server_completion_data.item.import_to_add() {
+                    append_import_edits(
+                        &mut original_completion,
+                        import_to_add,
+                        snap.analysis.file_line_index(server_completion_data.file_id)?.as_ref(),
+                        snap.file_line_endings(server_completion_data.file_id),
+                    );
                 }
-                Err(e) => log::error!("Failed to deserialize completion resolve metadata: {}", e),
             }
+            // TODO kb calculate the rest also?
+            _ => {}
         }
-        None => (),
     }
-    Ok(original_completion)
-}
 
-// TODO kb what to do when no resolve is available on the client?
-fn resolve_additional_edits(
-    import_to_add: &ImportToAdd,
-    line_index: Arc<LineIndex>,
-    line_endings: LineEndings,
-) -> Option<Vec<lsp_types::TextEdit>> {
-    let _p = profile::span("resolve_additional_edits");
-
-    let rewriter = insert_use::insert_use(
-        &import_to_add.import_scope,
-        mod_path_to_ast(&import_to_add.import_path),
-        import_to_add.merge_behaviour,
-    );
-    let old_ast = rewriter.rewrite_root()?;
-    let mut import_insert = TextEdit::builder();
-    algo::diff(&old_ast, &rewriter.rewrite(&old_ast)).into_text_edit(&mut import_insert);
-    let text_edit = import_insert.finish();
-
-    Some(
-        text_edit
-            .into_iter()
-            .map(|indel| to_proto::text_edit(&line_index, line_endings, indel))
-            .collect_vec(),
-    )
+    Ok(original_completion)
 }
 
 pub(crate) fn handle_folding_range(
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 01eabe852..aa542f5d1 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -5,14 +5,19 @@ use std::{
 };
 
 use ide::{
-    Assist, AssistKind, CallInfo, CompletionItem, CompletionItemKind, Documentation,
-    FileSystemEdit, Fold, FoldKind, Highlight, HighlightModifier, HighlightTag, HighlightedRange,
-    Indel, InlayHint, InlayKind, InsertTextFormat, LineIndex, Markup, NavigationTarget,
-    ReferenceAccess, ResolvedAssist, Runnable, Severity, SourceChange, SourceFileEdit, TextEdit,
+    Assist, AssistKind, CallInfo, CompletionItem, CompletionItemKind, CompletionResolveCapability,
+    Documentation, FileSystemEdit, Fold, FoldKind, Highlight, HighlightModifier, HighlightTag,
+    HighlightedRange, ImportToAdd, Indel, InlayHint, InlayKind, InsertTextFormat, LineIndex,
+    Markup, NavigationTarget, ReferenceAccess, ResolvedAssist, Runnable, Severity, SourceChange,
+    SourceFileEdit, TextEdit,
+};
+use ide_db::{
+    base_db::{FileId, FileRange},
+    helpers::{insert_use, mod_path_to_ast},
 };
-use ide_db::base_db::{FileId, FileRange};
 use itertools::Itertools;
-use syntax::{SyntaxKind, TextRange, TextSize};
+use rustc_hash::FxHashSet;
+use syntax::{algo, SyntaxKind, TextRange, TextSize};
 
 use crate::{
     cargo_target_spec::CargoTargetSpec, global_state::GlobalStateSnapshot,
@@ -158,6 +163,7 @@ pub(crate) fn completion_item(
     line_index: &LineIndex,
     line_endings: LineEndings,
     completion_item: CompletionItem,
+    resolve_capabilities: &FxHashSet<CompletionResolveCapability>,
 ) -> Vec<lsp_types::CompletionItem> {
     fn set_score(res: &mut lsp_types::CompletionItem, label: &str) {
         res.preselect = Some(true);
@@ -231,9 +237,17 @@ pub(crate) fn completion_item(
         None => vec![res],
     };
 
+    let unapplied_import_data = completion_item.import_to_add().filter(|_| {
+        !resolve_capabilities.contains(&CompletionResolveCapability::AdditionalTextEdits)
+    });
+
     for mut r in all_results.iter_mut() {
         r.insert_text_format = Some(insert_text_format(completion_item.insert_text_format()));
+        if let Some(unapplied_import_data) = unapplied_import_data {
+            append_import_edits(r, unapplied_import_data, line_index, line_endings);
+        }
     }
+
     all_results
 }
 
@@ -817,6 +831,47 @@ pub(crate) fn markup_content(markup: Markup) -> lsp_types::MarkupContent {
     lsp_types::MarkupContent { kind: lsp_types::MarkupKind::Markdown, value }
 }
 
+pub(crate) fn import_into_edits(
+    import_to_add: &ImportToAdd,
+    line_index: &LineIndex,
+    line_endings: LineEndings,
+) -> Option<Vec<lsp_types::TextEdit>> {
+    let _p = profile::span("add_import_edits");
+
+    let rewriter = insert_use::insert_use(
+        &import_to_add.import_scope,
+        mod_path_to_ast(&import_to_add.import_path),
+        import_to_add.merge_behaviour,
+    );
+    let old_ast = rewriter.rewrite_root()?;
+    let mut import_insert = TextEdit::builder();
+    algo::diff(&old_ast, &rewriter.rewrite(&old_ast)).into_text_edit(&mut import_insert);
+    let import_edit = import_insert.finish();
+
+    Some(
+        import_edit
+            .into_iter()
+            .map(|indel| text_edit(line_index, line_endings, indel))
+            .collect_vec(),
+    )
+}
+
+pub(crate) fn append_import_edits(
+    completion: &mut lsp_types::CompletionItem,
+    import_to_add: &ImportToAdd,
+    line_index: &LineIndex,
+    line_endings: LineEndings,
+) {
+    let new_edits = import_into_edits(import_to_add, line_index, line_endings);
+    if let Some(original_additional_edits) = completion.additional_text_edits.as_mut() {
+        if let Some(mut new_edits) = new_edits {
+            original_additional_edits.extend(new_edits.drain(..))
+        }
+    } else {
+        completion.additional_text_edits = new_edits;
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use ide::Analysis;
@@ -836,6 +891,7 @@ mod tests {
         let (offset, text) = test_utils::extract_offset(fixture);
         let line_index = LineIndex::new(&text);
         let (analysis, file_id) = Analysis::from_single_file(text);
+        let resolve_caps = FxHashSet::default();
         let completions: Vec<(String, Option<String>)> = analysis
             .completions(
                 &ide::CompletionConfig::default(),
@@ -845,7 +901,7 @@ mod tests {
             .unwrap()
             .into_iter()
             .filter(|c| c.label().ends_with("arg"))
-            .map(|c| completion_item(&line_index, LineEndings::Unix, c))
+            .map(|c| completion_item(&line_index, LineEndings::Unix, c, &resolve_caps))
             .flat_map(|comps| comps.into_iter().map(|c| (c.label, c.sort_text)))
             .collect();
         expect_test::expect![[r#"