feat: Implement inlay hint tooltips

Author: Veykril

crates/rust-analyzer/src/caps.rs

@@ -4,7 +4,8 @@ use lsp_types::{
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions, DeclarationCapability,
     DocumentOnTypeFormattingOptions, FileOperationFilter, FileOperationPattern,
     FileOperationPatternKind, FileOperationRegistrationOptions, FoldingRangeProviderCapability,
-    HoverProviderCapability, ImplementationProviderCapability, OneOf, RenameOptions, SaveOptions,
+    HoverProviderCapability, ImplementationProviderCapability, InlayHintOptions,
+    InlayHintServerCapabilities, OneOf, RenameOptions, SaveOptions,
     SelectionRangeProviderCapability, SemanticTokensFullOptions, SemanticTokensLegend,
     SemanticTokensOptions, ServerCapabilities, SignatureHelpOptions, TextDocumentSyncCapability,
     TextDocumentSyncKind, TextDocumentSyncOptions, TypeDefinitionProviderCapability,
@@ -112,7 +113,12 @@ pub fn server_capabilities(config: &Config) -> ServerCapabilities {
             .into(),
         ),
         moniker_provider: None,
-        inlay_hint_provider: Some(OneOf::Left(true)),
+        inlay_hint_provider: Some(OneOf::Right(InlayHintServerCapabilities::Options(
+            InlayHintOptions {
+                work_done_progress_options: Default::default(),
+                resolve_provider: Some(true),
+            },
+        ))),
         experimental: Some(json!({
             "externalDocs": true,
             "hoverRange": true,

crates/rust-analyzer/src/handlers.rs

@@ -1348,6 +1348,19 @@ pub(crate) fn handle_inlay_hints(
     ))
 }
 
+pub(crate) fn handle_inlay_hints_resolve(
+    _snap: GlobalStateSnapshot,
+    mut hint: InlayHint,
+) -> Result<InlayHint> {
+    if let lsp_types::InlayHintLabel::String(s) = &hint.label {
+        hint.tooltip = Some(lsp_types::InlayHintTooltip::MarkupContent(lsp_types::MarkupContent {
+            kind: lsp_types::MarkupKind::PlainText,
+            value: s.clone(),
+        }));
+    }
+    Ok(hint)
+}
+
 pub(crate) fn handle_call_hierarchy_prepare(
     snap: GlobalStateSnapshot,
     params: CallHierarchyPrepareParams,

crates/rust-analyzer/src/main_loop.rs

@@ -612,6 +612,7 @@ impl GlobalState {
             .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)
             .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)
             .on::<lsp_types::request::InlayHintRequest>(handlers::handle_inlay_hints)
+            .on::<lsp_types::request::InlayHintResolveRequest>(handlers::handle_inlay_hints_resolve)
             .on::<lsp_types::request::Completion>(handlers::handle_completion)
             .on::<lsp_types::request::ResolveCompletionItem>(handlers::handle_completion_resolve)
             .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)