Allow inlay hint tooltips to trigger hovers

crates/ide/src/inlay_hints.rs

@@ -48,7 +48,7 @@ pub enum ReborrowHints {
 pub enum InlayKind {
     BindingModeHint,
     ChainingHint,
-    ClosingBraceHint(Option<TextSize>),
+    ClosingBraceHint,
     ClosureReturnTypeHint,
     GenericParamListHint,
     ImplicitReborrowHint,
@@ -57,11 +57,19 @@ pub enum InlayKind {
     TypeHint,
 }
 
+// FIXME: This should live somewhere more general
+#[derive(Debug)]
+pub enum RangeOrOffset {
+    Range(TextRange),
+    Offset(TextSize),
+}
+
 #[derive(Debug)]
 pub struct InlayHint {
     pub range: TextRange,
     pub kind: InlayKind,
     pub label: String,
+    pub hover_trigger: Option<RangeOrOffset>,
 }
 
 // Feature: Inlay Hints
@@ -253,8 +261,9 @@ fn closing_brace_hints(
 
     acc.push(InlayHint {
         range: closing_token.text_range(),
-        kind: InlayKind::ClosingBraceHint(name_offset),
+        kind: InlayKind::ClosingBraceHint,
         label,
+        hover_trigger: name_offset.map(RangeOrOffset::Offset),
     });
 
     None
@@ -273,6 +282,7 @@ fn lifetime_fn_hints(
         range: t.text_range(),
         kind: InlayKind::LifetimeHint,
         label,
+        hover_trigger: None,
     };
 
     let param_list = func.param_list()?;
@@ -431,6 +441,7 @@ fn lifetime_fn_hints(
             range: func.name()?.syntax().text_range(),
             kind: InlayKind::GenericParamListHint,
             label: format!("<{}>", allocated_lifetimes.iter().format(", "),).into(),
+            hover_trigger: None,
         }),
     }
     Some(())
@@ -464,6 +475,7 @@ fn closure_ret_hints(
         kind: InlayKind::ClosureReturnTypeHint,
         label: hint_iterator(sema, &famous_defs, config, &ty)
             .unwrap_or_else(|| ty.display_truncated(sema.db, config.max_length).to_string()),
+        hover_trigger: None,
     });
     Some(())
 }
@@ -490,6 +502,7 @@ fn reborrow_hints(
         range: expr.syntax().text_range(),
         kind: InlayKind::ImplicitReborrowHint,
         label: label.to_string(),
+        hover_trigger: None,
     });
     Some(())
 }
@@ -548,6 +561,7 @@ fn chaining_hints(
                 label: hint_iterator(sema, &famous_defs, config, &ty).unwrap_or_else(|| {
                     ty.display_truncated(sema.db, config.max_length).to_string()
                 }),
+                hover_trigger: Some(RangeOrOffset::Range(expr.syntax().text_range())),
             });
         }
     }
@@ -588,6 +602,8 @@ fn param_name_hints(
             range,
             kind: InlayKind::ParameterHint,
             label: param_name.into(),
+            // FIXME: Show hover for parameter
+            hover_trigger: None,
         });
 
     acc.extend(hints);
@@ -613,7 +629,12 @@ fn binding_mode_hints(
             (true, false) => "&",
             _ => return,
         };
-        acc.push(InlayHint { range, kind: InlayKind::BindingModeHint, label: r.to_string() });
+        acc.push(InlayHint {
+            range,
+            kind: InlayKind::BindingModeHint,
+            label: r.to_string(),
+            hover_trigger: None,
+        });
     });
     match pat {
         ast::Pat::IdentPat(pat) if pat.ref_token().is_none() && pat.mut_token().is_none() => {
@@ -623,7 +644,12 @@ fn binding_mode_hints(
                 hir::BindingMode::Ref(Mutability::Mut) => "ref mut",
                 hir::BindingMode::Ref(Mutability::Shared) => "ref",
             };
-            acc.push(InlayHint { range, kind: InlayKind::BindingModeHint, label: bm.to_string() });
+            acc.push(InlayHint {
+                range,
+                kind: InlayKind::BindingModeHint,
+                label: bm.to_string(),
+                hover_trigger: None,
+            });
         }
         _ => (),
     }
@@ -673,6 +699,7 @@ fn bind_pat_hints(
         },
         kind: InlayKind::TypeHint,
         label,
+        hover_trigger: pat.name().map(|it| it.syntax().text_range()).map(RangeOrOffset::Range),
     });
 
     Some(())

crates/ide/src/lib.rs

@@ -80,7 +80,9 @@ pub use crate::{
     folding_ranges::{Fold, FoldKind},
     highlight_related::{HighlightRelatedConfig, HighlightedRange},
     hover::{HoverAction, HoverConfig, HoverDocFormat, HoverGotoTypeData, HoverResult},
-    inlay_hints::{InlayHint, InlayHintsConfig, InlayKind, LifetimeElisionHints, ReborrowHints},
+    inlay_hints::{
+        InlayHint, InlayHintsConfig, InlayKind, LifetimeElisionHints, RangeOrOffset, ReborrowHints,
+    },
     join_lines::JoinLinesConfig,
     markup::Markup,
     moniker::{MonikerKind, MonikerResult, PackageInformation},

crates/rust-analyzer/src/handlers.rs

@@ -1360,21 +1360,23 @@ pub(crate) fn handle_inlay_hints_resolve(
     mut hint: InlayHint,
 ) -> Result<InlayHint> {
     let _p = profile::span("handle_inlay_hints_resolve");
-    let succ = (|| {
     let data = match hint.data.take() {
         Some(it) => it,
-            None => return Ok(None),
+        None => return Ok(hint),
     };
 
     let resolve_data: lsp_ext::InlayHintResolveData = serde_json::from_value(data)?;
 
     let file_range = from_proto::file_range(
         &snap,
-            resolve_data.position.text_document,
+        resolve_data.text_document,
-            Range::new(resolve_data.position.position, resolve_data.position.position),
+        match resolve_data.position {
+            PositionOrRange::Position(pos) => Range::new(pos, pos),
+            PositionOrRange::Range(range) => range,
+        },
     )?;
     let info = match snap.analysis.hover(&snap.config.hover(), file_range)? {
-            None => return Ok(None),
+        None => return Ok(hint),
         Some(info) => info,
     };
 
@@ -1386,20 +1388,6 @@ pub(crate) fn handle_inlay_hints_resolve(
         info.info.markup,
         markup_kind,
     )));
-        Result::<_, crate::Error>::Ok(Some(()))
-    })()?
-    .is_some();
-
-    if !succ {
-        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)
 }
 

crates/rust-analyzer/src/lsp_ext.rs

@@ -520,7 +520,8 @@ pub struct CompletionResolveData {
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct InlayHintResolveData {
-    pub position: lsp_types::TextDocumentPositionParams,
+    pub text_document: TextDocumentIdentifier,
+    pub position: PositionOrRange,
 }
 
 #[derive(Debug, Serialize, Deserialize)]

crates/rust-analyzer/src/to_proto.rs

@@ -432,11 +432,11 @@ pub(crate) fn inlay_hint(
             | InlayKind::ChainingHint
             | InlayKind::GenericParamListHint
             | InlayKind::LifetimeHint
-            | InlayKind::ClosingBraceHint(_) => position(line_index, inlay_hint.range.end()),
+            | InlayKind::ClosingBraceHint => position(line_index, inlay_hint.range.end()),
         },
         padding_left: Some(match inlay_hint.kind {
             InlayKind::TypeHint => !render_colons,
-            InlayKind::ChainingHint | InlayKind::ClosingBraceHint(_) => true,
+            InlayKind::ChainingHint | InlayKind::ClosingBraceHint => true,
             InlayKind::BindingModeHint
             | InlayKind::ClosureReturnTypeHint
             | InlayKind::GenericParamListHint
@@ -450,7 +450,7 @@ pub(crate) fn inlay_hint(
             | InlayKind::GenericParamListHint
             | InlayKind::ImplicitReborrowHint
             | InlayKind::TypeHint
-            | InlayKind::ClosingBraceHint(_) => false,
+            | InlayKind::ClosingBraceHint => false,
             InlayKind::BindingModeHint => inlay_hint.label != "&",
             InlayKind::ParameterHint | InlayKind::LifetimeHint => true,
         }),
@@ -458,7 +458,7 @@ pub(crate) fn inlay_hint(
             InlayKind::ParameterHint if render_colons => format!("{}:", inlay_hint.label),
             InlayKind::TypeHint if render_colons => format!(": {}", inlay_hint.label),
             InlayKind::ClosureReturnTypeHint => format!(" -> {}", inlay_hint.label),
-            _ => inlay_hint.label,
+            _ => inlay_hint.label.clone(),
         }),
         kind: match inlay_hint.kind {
             InlayKind::ParameterHint => Some(lsp_types::InlayHintKind::PARAMETER),
@@ -469,22 +469,24 @@ pub(crate) fn inlay_hint(
             | InlayKind::GenericParamListHint
             | InlayKind::LifetimeHint
             | InlayKind::ImplicitReborrowHint
-            | InlayKind::ClosingBraceHint(_) => None,
+            | InlayKind::ClosingBraceHint => None,
         },
         text_edits: None,
-        tooltip: None,
+        tooltip: Some(lsp_types::InlayHintTooltip::String(inlay_hint.label)),
-        data: match inlay_hint.kind {
+        data: inlay_hint.hover_trigger.map(|range_or_offset| {
-            InlayKind::ClosingBraceHint(Some(offset)) => Some(
             to_value(lsp_ext::InlayHintResolveData {
-                    position: lsp_types::TextDocumentPositionParams {
                 text_document: text_document.clone(),
-                        position: position(line_index, offset),
+                position: match range_or_offset {
+                    ide::RangeOrOffset::Offset(offset) => {
+                        lsp_ext::PositionOrRange::Position(position(line_index, offset))
+                    }
+                    ide::RangeOrOffset::Range(text_range) => {
+                        lsp_ext::PositionOrRange::Range(range(line_index, text_range))
+                    }
                 },
             })
-                .unwrap(),
+            .unwrap()
-            ),
+        }),
-            _ => None,
-        },
     }
 }