YAGNI active_resolve_capabilities

This leaks a lot of LSP details into ide layer, which we want to avoid:

https://github.com/rust-analyzer/rust-analyzer/tree/c9cec381bcfd97e5f3536e31a9c546ab5c0665e6/docs/dev#lsp-independence

Additionally, all what this infra does is providing a toggle for
auto-import completion, but we already have one!

7 files changed, 32 insertions, 78 deletions

diff --git a/crates/completion/src/completions/unqualified_path.rs b/crates/completion/src/completions/unqualified_path.rs
index 2f41a3f96..896f167ff 100644
--- a/crates/completion/src/completions/unqualified_path.rs
+++ b/crates/completion/src/completions/unqualified_path.rs
@@ -46,7 +46,7 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         acc.add_resolution(ctx, name.to_string(), &res)
     });
 
-    if ctx.config.enable_autoimport_completions && ctx.config.resolve_additional_edits_lazily() {
+    if ctx.config.enable_autoimport_completions {
         fuzzy_completion(acc, ctx);
     }
 }
@@ -206,11 +206,7 @@ mod tests {
     }
 
     fn fuzzy_completion_config() -> CompletionConfig {
-        let mut completion_config = CompletionConfig::default();
-        completion_config
-            .active_resolve_capabilities
-            .insert(crate::CompletionResolveCapability::AdditionalTextEdits);
-        completion_config
+        CompletionConfig::default()
     }
 
     #[test]
diff --git a/crates/completion/src/config.rs b/crates/completion/src/config.rs
index 30577dc11..9f82b0346 100644
--- a/crates/completion/src/config.rs
+++ b/crates/completion/src/config.rs
@@ -5,7 +5,6 @@
 //! completions if we are allowed to.
 
 use ide_db::helpers::insert_use::MergeBehavior;
-use rustc_hash::FxHashSet;
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CompletionConfig {
@@ -15,32 +14,12 @@ pub struct CompletionConfig {
     pub add_call_argument_snippets: bool,
     pub snippet_cap: Option<SnippetCap>,
     pub merge: Option<MergeBehavior>,
-    /// A set of capabilities, enabled on the client and supported on the server.
-    pub active_resolve_capabilities: FxHashSet<CompletionResolveCapability>,
-}
-
-/// A resolve capability, supported on the server.
-/// If the client registers any completion resolve capabilities,
-/// the server is able to render completion items' corresponding fields later,
-/// not during an initial completion item request.
-/// See https://github.com/rust-analyzer/rust-analyzer/issues/6366 for more details.
-#[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]
-pub enum CompletionResolveCapability {
-    Documentation,
-    Detail,
-    AdditionalTextEdits,
 }
 
 impl CompletionConfig {
     pub fn allow_snippets(&mut self, yes: bool) {
         self.snippet_cap = if yes { Some(SnippetCap { _private: () }) } else { None }
     }
-
-    /// Whether the completions' additional edits are calculated when sending an initional completions list
-    /// or later, in a separate resolve request.
-    pub fn resolve_additional_edits_lazily(&self) -> bool {
-        self.active_resolve_capabilities.contains(&CompletionResolveCapability::AdditionalTextEdits)
-    }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -57,7 +36,6 @@ impl Default for CompletionConfig {
             add_call_argument_snippets: true,
             snippet_cap: Some(SnippetCap { _private: () }),
             merge: Some(MergeBehavior::Full),
-            active_resolve_capabilities: FxHashSet::default(),
         }
     }
 }
diff --git a/crates/completion/src/lib.rs b/crates/completion/src/lib.rs
index c57d05bbe..366aced71 100644
--- a/crates/completion/src/lib.rs
+++ b/crates/completion/src/lib.rs
@@ -20,7 +20,7 @@ use text_edit::TextEdit;
 use crate::{completions::Completions, context::CompletionContext, item::CompletionKind};
 
 pub use crate::{
-    config::{CompletionConfig, CompletionResolveCapability},
+    config::CompletionConfig,
     item::{CompletionItem, CompletionItemKind, CompletionScore, ImportEdit, InsertTextFormat},
 };
 
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index a450794f3..72c8bfd09 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -82,8 +82,8 @@ pub use crate::{
 };
 pub use assists::{Assist, AssistConfig, AssistId, AssistKind};
 pub use completion::{
-    CompletionConfig, CompletionItem, CompletionItemKind, CompletionResolveCapability,
-    CompletionScore, ImportEdit, InsertTextFormat,
+    CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, ImportEdit,
+    InsertTextFormat,
 };
 pub use hir::{Documentation, Semantics};
 pub use ide_db::base_db::{
diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index 80e46bf7f..3db0d55c5 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -1,7 +1,6 @@
 //! Advertizes the capabilities of the LSP Server.
 use std::env;
 
-use ide::CompletionResolveCapability;
 use lsp_types::{
     CallHierarchyServerCapability, ClientCapabilities, CodeActionKind, CodeActionOptions,
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
@@ -14,7 +13,6 @@ use lsp_types::{
     WorkDoneProgressOptions, WorkspaceFileOperationsServerCapabilities,
     WorkspaceServerCapabilities,
 };
-use rustc_hash::FxHashSet;
 use serde_json::json;
 
 use crate::semantic_tokens;
@@ -118,37 +116,31 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
 }
 
 fn completions_resolve_provider(client_caps: &ClientCapabilities) -> Option<bool> {
-    if enabled_completions_resolve_capabilities(client_caps)?.is_empty() {
+    if completion_item_edit_resolve(client_caps) {
+        Some(true)
+    } else {
         log::info!("No `additionalTextEdits` completion resolve capability was found in the client capabilities, autoimport completion is disabled");
         None
-    } else {
-        Some(true)
     }
 }
 
 /// Parses client capabilities and returns all completion resolve capabilities rust-analyzer supports.
-pub(crate) fn enabled_completions_resolve_capabilities(
-    caps: &ClientCapabilities,
-) -> Option<FxHashSet<CompletionResolveCapability>> {
-    Some(
-        caps.text_document
-            .as_ref()?
-            .completion
-            .as_ref()?
-            .completion_item
-            .as_ref()?
-            .resolve_support
-            .as_ref()?
-            .properties
-            .iter()
-            .filter_map(|cap_string| match cap_string.as_str() {
-                "additionalTextEdits" => Some(CompletionResolveCapability::AdditionalTextEdits),
-                "detail" => Some(CompletionResolveCapability::Detail),
-                "documentation" => Some(CompletionResolveCapability::Documentation),
-                _unsupported => None,
-            })
-            .collect(),
-    )
+pub(crate) fn completion_item_edit_resolve(caps: &ClientCapabilities) -> bool {
+    (|| {
+        Some(
+            caps.text_document
+                .as_ref()?
+                .completion
+                .as_ref()?
+                .completion_item
+                .as_ref()?
+                .resolve_support
+                .as_ref()?
+                .properties
+                .iter()
+                .any(|cap_string| cap_string.as_str() == "additionalTextEdits"),
+        )
+    })() == Some(true)
 }
 
 fn code_action_capabilities(client_caps: &ClientCapabilities) -> CodeActionProviderCapability {
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 24e7936fc..ce9526315 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -20,7 +20,7 @@ use rustc_hash::FxHashSet;
 use serde::{de::DeserializeOwned, Deserialize};
 use vfs::AbsPathBuf;
 
-use crate::{caps::enabled_completions_resolve_capabilities, diagnostics::DiagnosticsMapConfig};
+use crate::{caps::completion_item_edit_resolve, diagnostics::DiagnosticsMapConfig};
 
 config_data! {
     struct ConfigData {
@@ -536,12 +536,11 @@ impl Config {
     pub fn completion(&self) -> CompletionConfig {
         let mut res = CompletionConfig::default();
         res.enable_postfix_completions = self.data.completion_postfix_enable;
-        res.enable_autoimport_completions = self.data.completion_autoimport_enable;
+        res.enable_autoimport_completions =
+            self.data.completion_autoimport_enable && completion_item_edit_resolve(&self.caps);
         res.add_call_parenthesis = self.data.completion_addCallParenthesis;
         res.add_call_argument_snippets = self.data.completion_addCallArgumentSnippets;
         res.merge = self.merge_behavior();
-        res.active_resolve_capabilities =
-            enabled_completions_resolve_capabilities(&self.caps).unwrap_or_default();
 
         res.allow_snippets(try_or!(
             self.caps
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 33661325a..a7bf0ec6a 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -9,9 +9,8 @@ use std::{
 };
 
 use ide::{
-    CompletionResolveCapability, FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData,
-    LineIndex, NavigationTarget, Query, RangeInfo, Runnable, RunnableKind, SearchScope,
-    SourceChange, SymbolKind, TextEdit,
+    FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, LineIndex, NavigationTarget,
+    Query, RangeInfo, Runnable, RunnableKind, SearchScope, SourceChange, SymbolKind, TextEdit,
 };
 use itertools::Itertools;
 use lsp_server::ErrorCode;
@@ -634,10 +633,9 @@ pub(crate) fn handle_completion(
             let mut new_completion_items =
                 to_proto::completion_item(&line_index, line_endings, item.clone());
 
-            if completion_config.resolve_additional_edits_lazily() {
+            if completion_config.enable_autoimport_completions {
                 for new_item in &mut new_completion_items {
-                    let _ = fill_resolve_data(&mut new_item.data, &item, &text_document_position)
-                        .take();
+                    fill_resolve_data(&mut new_item.data, &item, &text_document_position);
                 }
             }
 
@@ -663,15 +661,6 @@ pub(crate) fn handle_completion_resolve(
         .into());
     }
 
-    // FIXME resolve the other capabilities also?
-    let completion_config = &snap.config.completion();
-    if !completion_config
-        .active_resolve_capabilities
-        .contains(&CompletionResolveCapability::AdditionalTextEdits)
-    {
-        return Ok(original_completion);
-    }
-
     let resolve_data = match original_completion
         .data
         .take()
@@ -690,7 +679,7 @@ pub(crate) fn handle_completion_resolve(
     let additional_edits = snap
         .analysis
         .resolve_completion_edits(
-            &completion_config,
+            &snap.config.completion(),
             FilePosition { file_id, offset },
             &resolve_data.full_import_path,
             resolve_data.imported_name,