8 files changed, 54 insertions, 32 deletions

diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index 00e601244..671aa1373 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -153,8 +153,7 @@ impl NavigationTarget {
         node: InFile<&dyn ast::NameOwner>,
         kind: SymbolKind,
     ) -> NavigationTarget {
-        let name =
-            node.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
+        let name = node.value.name().map(|it| it.text().into()).unwrap_or_else(|| "_".into());
         let focus_range =
             node.value.name().map(|it| node.with_value(it.syntax()).original_file_range(db).range);
         let frange = node.map(|it| it.syntax()).original_file_range(db);
diff --git a/crates/ide/src/display/short_label.rs b/crates/ide/src/display/short_label.rs
index 990f740b8..b8e4cc181 100644
--- a/crates/ide/src/display/short_label.rs
+++ b/crates/ide/src/display/short_label.rs
@@ -90,7 +90,7 @@ impl ShortLabel for ast::Variant {
 impl ShortLabel for ast::ConstParam {
     fn short_label(&self) -> Option<String> {
         let mut buf = "const ".to_owned();
-        buf.push_str(self.name()?.text().as_str());
+        buf.push_str(self.name()?.text());
         if let Some(type_ref) = self.ty() {
             format_to!(buf, ": {}", type_ref.syntax());
         }
@@ -117,6 +117,6 @@ where
 {
     let mut buf = node.visibility().map(|v| format!("{} ", v.syntax())).unwrap_or_default();
     buf.push_str(label);
-    buf.push_str(node.name()?.text().as_str());
+    buf.push_str(node.name()?.text());
     Some(buf)
 }
diff --git a/crates/ide/src/extend_selection.rs b/crates/ide/src/extend_selection.rs
index 17a540972..2d722dee0 100644
--- a/crates/ide/src/extend_selection.rs
+++ b/crates/ide/src/extend_selection.rs
@@ -213,8 +213,8 @@ fn extend_ws(root: &SyntaxNode, ws: SyntaxToken, offset: TextSize) -> TextRange
     let ws_text = ws.text();
     let suffix = TextRange::new(offset, ws.text_range().end()) - ws.text_range().start();
     let prefix = TextRange::new(ws.text_range().start(), offset) - ws.text_range().start();
-    let ws_suffix = &ws_text.as_str()[suffix];
-    let ws_prefix = &ws_text.as_str()[prefix];
+    let ws_suffix = &ws_text[suffix];
+    let ws_prefix = &ws_text[prefix];
     if ws_text.contains('\n') && !ws_suffix.contains('\n') {
         if let Some(node) = ws.next_sibling_or_token() {
             let start = match ws_prefix.rfind('\n') {
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index a2039fcc7..54485fd30 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -411,7 +411,7 @@ fn get_string_representation(expr: &ast::Expr) -> Option<String> {
     match expr {
         ast::Expr::MethodCallExpr(method_call_expr) => {
             let name_ref = method_call_expr.name_ref()?;
-            match name_ref.text().as_str() {
+            match name_ref.text() {
                 "clone" => method_call_expr.receiver().map(|rec| rec.to_string()),
                 name_ref => Some(name_ref.to_owned()),
             }
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
index 981467c8d..631bde0f1 100644
--- a/crates/ide/src/join_lines.rs
+++ b/crates/ide/src/join_lines.rs
@@ -59,7 +59,7 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextS
         // The node is either the first or the last in the file
         let suff = &token.text()[TextRange::new(
             offset - token.text_range().start() + TextSize::of('\n'),
-            TextSize::of(token.text().as_str()),
+            TextSize::of(token.text()),
         )];
         let spaces = suff.bytes().take_while(|&b| b == b' ').count();
 
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 8976f1080..47a85dc45 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -9,6 +9,7 @@ use syntax::{
     ast::{self, AstNode, AttrsOwner},
     match_ast, SyntaxNode,
 };
+use test_utils::mark;
 
 use crate::{
     display::{ToNav, TryToNav},
@@ -96,28 +97,26 @@ impl Runnable {
 pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
     let sema = Semantics::new(db);
     let module = match sema.to_module_def(file_id) {
-        None => return vec![],
+        None => return Vec::new(),
         Some(it) => it,
     };
 
-    runnables_mod(&sema, module)
+    let mut res = Vec::new();
+    runnables_mod(&sema, &mut res, module);
+    res
 }
 
-fn runnables_mod(sema: &Semantics<RootDatabase>, module: hir::Module) -> Vec<Runnable> {
-    let mut res: Vec<Runnable> = module
-        .declarations(sema.db)
-        .into_iter()
-        .filter_map(|def| {
-            let runnable = match def {
-                hir::ModuleDef::Module(it) => runnable_mod(&sema, it),
-                hir::ModuleDef::Function(it) => runnable_fn(&sema, it),
-                _ => None,
-            };
-            runnable.or_else(|| module_def_doctest(&sema, def))
-        })
-        .collect();
+fn runnables_mod(sema: &Semantics<RootDatabase>, acc: &mut Vec<Runnable>, module: hir::Module) {
+    acc.extend(module.declarations(sema.db).into_iter().filter_map(|def| {
+        let runnable = match def {
+            hir::ModuleDef::Module(it) => runnable_mod(&sema, it),
+            hir::ModuleDef::Function(it) => runnable_fn(&sema, it),
+            _ => None,
+        };
+        runnable.or_else(|| module_def_doctest(&sema, def))
+    }));
 
-    res.extend(module.impl_defs(sema.db).into_iter().flat_map(|it| it.items(sema.db)).filter_map(
+    acc.extend(module.impl_defs(sema.db).into_iter().flat_map(|it| it.items(sema.db)).filter_map(
         |def| match def {
             hir::AssocItem::Function(it) => {
                 runnable_fn(&sema, it).or_else(|| module_def_doctest(&sema, it.into()))
@@ -127,12 +126,14 @@ fn runnables_mod(sema: &Semantics<RootDatabase>, module: hir::Module) -> Vec<Run
         },
     ));
 
-    res.extend(module.declarations(sema.db).into_iter().flat_map(|def| match def {
-        hir::ModuleDef::Module(it) => runnables_mod(sema, it),
-        _ => vec![],
-    }));
-
-    res
+    for def in module.declarations(sema.db) {
+        if let hir::ModuleDef::Module(submodule) = def {
+            match submodule.definition_source(sema.db).value {
+                hir::ModuleSource::Module(_) => runnables_mod(sema, acc, submodule),
+                hir::ModuleSource::SourceFile(_) => mark::hit!(dont_recurse_in_outline_submodules),
+            }
+        }
+    }
 }
 
 pub(crate) fn runnable_fn(sema: &Semantics<RootDatabase>, def: hir::Function) -> Option<Runnable> {
@@ -326,6 +327,7 @@ fn has_test_function_or_multiple_test_submodules(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
+    use test_utils::mark;
 
     use crate::fixture;
 
@@ -1050,4 +1052,25 @@ mod tests {
             "#]],
         );
     }
+
+    #[test]
+    fn dont_recurse_in_outline_submodules() {
+        mark::check!(dont_recurse_in_outline_submodules);
+        check(
+            r#"
+//- /lib.rs
+$0
+mod m;
+//- /m.rs
+mod tests {
+    #[test]
+    fn t() {}
+}
+"#,
+            &[],
+            expect![[r#"
+                []
+            "#]],
+        );
+    }
 }
diff --git a/crates/ide/src/syntax_highlighting/format.rs b/crates/ide/src/syntax_highlighting/format.rs
index a74ca844b..8a9b5ca8c 100644
--- a/crates/ide/src/syntax_highlighting/format.rs
+++ b/crates/ide/src/syntax_highlighting/format.rs
@@ -30,7 +30,7 @@ fn is_format_string(string: &ast::String) -> Option<()> {
     let parent = string.syntax().parent();
 
     let name = parent.parent().and_then(ast::MacroCall::cast)?.path()?.segment()?.name_ref()?;
-    if !matches!(name.text().as_str(), "format_args" | "format_args_nl") {
+    if !matches!(name.text(), "format_args" | "format_args_nl") {
         return None;
     }
 
diff --git a/crates/ide/src/syntax_highlighting/inject.rs b/crates/ide/src/syntax_highlighting/inject.rs
index 281461493..8cdc3688f 100644
--- a/crates/ide/src/syntax_highlighting/inject.rs
+++ b/crates/ide/src/syntax_highlighting/inject.rs
@@ -116,7 +116,7 @@ pub(super) fn doc_comment(hl: &mut Highlights, node: &SyntaxNode) {
             None => (),
         }
 
-        let line: &str = comment.text().as_str();
+        let line: &str = comment.text();
         let range = comment.syntax().text_range();
 
         let mut pos = TextSize::of(comment.prefix());