feat(lsp): Implement `textDocument/signatureHelp` (#9330)

Co-authored-by: Kitson Kelly <me@kitsonkelly.com>

2 files changed, 18 insertions, 0 deletions

diff --git a/cli/tsc/99_main_compiler.js b/cli/tsc/99_main_compiler.js
index 50631e83f..f8eabc890 100644
--- a/cli/tsc/99_main_compiler.js
+++ b/cli/tsc/99_main_compiler.js
@@ -677,6 +677,16 @@ delete Object.prototype.__proto__;
           ),
         );
       }
+      case "getSignatureHelpItems": {
+        return respond(
+          id,
+          languageService.getSignatureHelpItems(
+            request.specifier,
+            request.position,
+            request.options,
+          ),
+        );
+      }
       case "getSupportedCodeFixes": {
         return respond(
           id,
diff --git a/cli/tsc/compiler.d.ts b/cli/tsc/compiler.d.ts
index 4e5dcdb96..7d102eb56 100644
--- a/cli/tsc/compiler.d.ts
+++ b/cli/tsc/compiler.d.ts
@@ -54,6 +54,7 @@ declare global {
     | GetNavigationTree
     | GetQuickInfoRequest
     | GetReferencesRequest
+    | GetSignatureHelpItemsRequest
     | GetSupportedCodeFixes;
 
   interface BaseLanguageServerRequest {
@@ -144,6 +145,13 @@ declare global {
     position: number;
   }
 
+  interface GetSignatureHelpItemsRequest extends BaseLanguageServerRequest {
+    method: "getSignatureHelpItems";
+    specifier: string;
+    position: number;
+    options: ts.SignatureHelpItemsOptions;
+  }
+
   interface GetSupportedCodeFixes extends BaseLanguageServerRequest {
     method: "getSupportedCodeFixes";
   }