project: Bring back language servers in detached worktrees (#23530)

Closes #ISSUE

Release Notes:

- N/A

crates/project/src/project_tree/server_tree.rs

@@ -128,6 +128,14 @@ impl InnerTreeNode {
     }
 }
 
+/// Determines how the list of adapters to query should be constructed.
+pub(crate) enum AdapterQuery<'a> {
+    /// Search for roots of all adapters associated with a given language name.
+    Language(&'a LanguageName),
+    /// Search for roots of adapter with a given name.
+    Adapter(&'a LanguageServerName),
+}
+
 impl LanguageServerTree {
     pub(crate) fn new(
         project_tree: Model<ProjectTree>,
@@ -159,7 +167,7 @@ impl LanguageServerTree {
     pub(crate) fn get<'a>(
         &'a mut self,
         path: ProjectPath,
-        language_name: &LanguageName,
+        query: AdapterQuery<'_>,
         delegate: Arc<dyn LspAdapterDelegate>,
         cx: &mut AppContext,
     ) -> impl Iterator<Item = LanguageServerTreeNode> + 'a {
@@ -167,7 +175,15 @@ impl LanguageServerTree {
             worktree_id: path.worktree_id,
             path: &path.path,
         };
-        let adapters = self.adapters_for_language(settings_location, language_name, cx);
+        let adapters = match query {
+            AdapterQuery::Language(language_name) => {
+                self.adapters_for_language(settings_location, language_name, cx)
+            }
+            AdapterQuery::Adapter(language_server_name) => IndexMap::from_iter(
+                self.adapter_for_name(language_server_name)
+                    .map(|adapter| (adapter, (LspSettings::default(), BTreeSet::new()))),
+            ),
+        };
         self.get_with_adapters(path, adapters, delegate, cx)
     }
 
@@ -231,6 +247,10 @@ impl LanguageServerTree {
         })
     }
 
+    fn adapter_for_name(&self, name: &LanguageServerName) -> Option<AdapterWrapper> {
+        self.languages.adapter_for_name(name).map(AdapterWrapper)
+    }
+
     fn adapters_for_language(
         &self,
         settings_location: SettingsLocation,