From d04fdf82c44e8d3223df70780efa4ac40affc26c Mon Sep 17 00:00:00 2001
From: Benjamin Friedman Wilson <benjamin.wilson@typefox.io>
Date: Fri, 17 Nov 2023 17:10:04 +0100
Subject: [PATCH] unsafe downcasts until service registry is changed

---
 packages/langium/src/lsp/language-server.ts | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/packages/langium/src/lsp/language-server.ts b/packages/langium/src/lsp/language-server.ts
index 146a74b52..33b805178 100644
--- a/packages/langium/src/lsp/language-server.ts
+++ b/packages/langium/src/lsp/language-server.ts
@@ -533,9 +533,10 @@ export function createCallHierarchyRequestHandler<P extends CallHierarchyIncomin
     };
 }
 
-export function addTypeHierarchyHandler(connection: Connection, sharedServices: LangiumSharedServices): void {
+export function addTypeHierarchyHandler(connection: Connection, sharedServices: LangiumSharedServices & LangiumSharedLSPServices): void {
     // Don't register type hierarchy handlers if no type hierarchy provider is registered
-    if (!sharedServices.ServiceRegistry.all.some(services => services.lsp.TypeHierarchyProvider)) {
+    // TODO @montymxb downcast is not safe, needs additional work
+    if (!sharedServices.ServiceRegistry.all.some(services => (services as LangiumCombinedServices).lsp.TypeHierarchyProvider)) {
         return;
     }
 
@@ -547,13 +548,15 @@ export function addTypeHierarchyHandler(connection: Connection, sharedServices:
 
     connection.languages.typeHierarchy.onSupertypes(
         createTypeHierarchyRequestHandler((services, params, cancelToken) => {
-            return services.lsp.TypeHierarchyProvider?.supertypes(params, cancelToken) ?? null;
+            // TODO @montymxb downcast is not safe, needs additional work
+            return (services as LangiumCombinedServices).lsp.TypeHierarchyProvider?.supertypes(params, cancelToken) ?? null;
         }, sharedServices),
     );
 
     connection.languages.typeHierarchy.onSubtypes(
         createTypeHierarchyRequestHandler((services, params, cancelToken) => {
-            return services.lsp.TypeHierarchyProvider?.subtypes(params, cancelToken) ?? null;
+            // TODO @montymxb downcast is not safe, needs additional work
+            return (services as LangiumCombinedServices).lsp.TypeHierarchyProvider?.subtypes(params, cancelToken) ?? null;
         }, sharedServices),
     );
 }