Merge #6706

6706: Move import text edit calculation into a completion resolve request r=matklad a=SomeoneToIgnore

Part of https://github.com/rust-analyzer/rust-analyzer/issues/6612 (presumably fixing it)
Part of https://github.com/rust-analyzer/rust-analyzer/issues/6366 (does not cover all possible resolve capabilities we can do)
Closes https://github.com/rust-analyzer/rust-analyzer/issues/6594

Further improves imports on completion performance by deferring the computations for import inserts.

To use the new mode, you have to have the experimental completions enabled and use the LSP 3.16-compliant client that reports `additionalTextEdits` in its `CompletionItemCapabilityResolveSupport` field in the client capabilities.
rust-analyzer VSCode extension does this already hence picks up the changes completely.

Performance implications are descrbed in: https://github.com/rust-analyzer/rust-analyzer/issues/6633#issuecomment-737295182

Co-authored-by: Kirill Bulatov <[email protected]>

1 files changed, 24 insertions, 2 deletions

diff --git a/crates/completion/src/config.rs b/crates/completion/src/config.rs
index 654a76f7b..5175b9d69 100644
--- a/crates/completion/src/config.rs
+++ b/crates/completion/src/config.rs
@@ -5,21 +5,42 @@
 //! completions if we are allowed to.
 
 use ide_db::helpers::insert_use::MergeBehaviour;
+use rustc_hash::FxHashSet;
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CompletionConfig {
     pub enable_postfix_completions: bool,
-    pub enable_experimental_completions: bool,
+    pub enable_autoimport_completions: bool,
     pub add_call_parenthesis: bool,
     pub add_call_argument_snippets: bool,
     pub snippet_cap: Option<SnippetCap>,
     pub merge: Option<MergeBehaviour>,
+    /// 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)]
@@ -31,11 +52,12 @@ impl Default for CompletionConfig {
     fn default() -> Self {
         CompletionConfig {
             enable_postfix_completions: true,
-            enable_experimental_completions: true,
+            enable_autoimport_completions: true,
             add_call_parenthesis: true,
             add_call_argument_snippets: true,
             snippet_cap: Some(SnippetCap { _private: () }),
             merge: Some(MergeBehaviour::Full),
+            active_resolve_capabilities: FxHashSet::default(),
         }
     }
 }