2 files changed, 14 insertions, 9 deletions

diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index a6ca68d86..d6a51b833 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,9 +1,9 @@
 use std::{fmt, any::Any};
 
-use ra_syntax::{SyntaxNodePtr, AstPtr, ast};
+use ra_syntax::{SyntaxNodePtr, TreeArc, AstPtr, TextRange, ast, SyntaxNode};
 use relative_path::RelativePathBuf;
 
-use crate::HirFileId;
+use crate::{HirFileId, HirDatabase};
 
 /// Diagnostic defines hir API for errors and warnings.
 ///
@@ -20,11 +20,18 @@ use crate::HirFileId;
 pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
     fn message(&self) -> String;
     fn file(&self) -> HirFileId;
-    fn syntax_node(&self) -> SyntaxNodePtr;
+    fn syntax_node_ptr(&self) -> SyntaxNodePtr;
+    fn highlight_range(&self) -> TextRange {
+        self.syntax_node_ptr().range()
+    }
     fn as_any(&self) -> &(dyn Any + Send + 'static);
 }
 
 impl dyn Diagnostic {
+    pub fn syntax_node(&self, db: &impl HirDatabase) -> TreeArc<SyntaxNode> {
+        let source_file = db.hir_parse(self.file());
+        self.syntax_node_ptr().to_node(&source_file).to_owned()
+    }
     pub fn downcast_ref<D: Diagnostic>(&self) -> Option<&D> {
         self.as_any().downcast_ref()
     }
@@ -77,7 +84,7 @@ impl Diagnostic for NoSuchField {
     fn file(&self) -> HirFileId {
         self.file
     }
-    fn syntax_node(&self) -> SyntaxNodePtr {
+    fn syntax_node_ptr(&self) -> SyntaxNodePtr {
         self.field.into()
     }
     fn as_any(&self) -> &(Any + Send + 'static) {
@@ -99,7 +106,7 @@ impl Diagnostic for UnresolvedModule {
     fn file(&self) -> HirFileId {
         self.file
     }
-    fn syntax_node(&self) -> SyntaxNodePtr {
+    fn syntax_node_ptr(&self) -> SyntaxNodePtr {
         self.decl.into()
     }
     fn as_any(&self) -> &(Any + Send + 'static) {
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index 08f927bb4..aeab6b180 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -9,7 +9,7 @@ use relative_path::RelativePathBuf;
 use test_utils::{parse_fixture, CURSOR_MARKER, extract_offset};
 use rustc_hash::FxHashMap;
 
-use crate::{db, HirInterner, diagnostics::DiagnosticSink, DefDatabase};
+use crate::{db, HirInterner, diagnostics::DiagnosticSink};
 
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
 
@@ -79,9 +79,7 @@ impl MockDatabase {
             module.diagnostics(
                 self,
                 &mut DiagnosticSink::new(|d| {
-                    let source_file = self.hir_parse(d.file());
-                    let syntax_node = d.syntax_node().to_node(&source_file);
-                    buf += &format!("{:?}: {}\n", syntax_node.text(), d.message());
+                    buf += &format!("{:?}: {}\n", d.syntax_node(self).text(), d.message());
                 }),
             )
         }