display Doctest code lens before comment #4785

Signed-off-by: Benjamin Coenen <5719034+bnjjj@users.noreply.github.com>

Author: bnjjj

crates/ra_ide/src/display/navigation_target.rs

@@ -4,6 +4,7 @@ use either::Either;
 use hir::{original_range, AssocItem, FieldSource, HasSource, InFile, ModuleSource};
 use ra_db::{FileId, SourceDatabase};
 use ra_ide_db::{defs::Definition, RootDatabase};
+use ra_syntax::ast::AstToken;
 use ra_syntax::{
     ast::{self, DocCommentsOwner, NameOwner},
     match_ast, AstNode, SmolStr,
@@ -135,8 +136,8 @@ impl NavigationTarget {
         db: &RootDatabase,
         node: InFile<&dyn ast::NameOwner>,
     ) -> NavigationTarget {
-        //FIXME: use `_` instead of empty string
-        let name = node.value.name().map(|it| it.text().clone()).unwrap_or_default();
+        let name =
+            node.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
         let focus_range =
             node.value.name().map(|it| original_range(db, node.with_value(it.syntax())).range);
         let frange = original_range(db, node.map(|it| it.syntax()));
@@ -150,6 +151,26 @@ impl NavigationTarget {
         )
     }
 
+    /// Allows `NavigationTarget` to be created from a `DocCommentsOwner` and a `NameOwner`
+    pub(crate) fn from_doc_commented(
+        db: &RootDatabase,
+        named: InFile<&dyn ast::NameOwner>,
+        node: InFile<&dyn ast::DocCommentsOwner>,
+    ) -> NavigationTarget {
+        let name =
+            named.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
+        let focus_range = node.value.doc_comments().next().map(|it| it.syntax().text_range());
+        let frange = original_range(db, node.map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            focus_range,
+            frange.range,
+            node.value.syntax().kind(),
+        )
+    }
+
     fn from_syntax(
         file_id: FileId,
         name: SmolStr,

crates/ra_ide/src/runnables.rs

@@ -171,7 +171,15 @@ fn runnable_fn(
     let cfg_exprs =
         attrs.by_key("cfg").tt_values().map(|subtree| ra_cfg::parse_cfg(subtree)).collect();
 
-    let nav = NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def));
+    let nav = if let RunnableKind::DocTest { .. } = kind {
+        NavigationTarget::from_doc_commented(
+            sema.db,
+            InFile::new(file_id.into(), &fn_def),
+            InFile::new(file_id.into(), &fn_def),
+        )
+    } else {
+        NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def))
+    };
     Some(Runnable { nav, kind, cfg_exprs })
 }