add option for disabling autoupdates

Installing the server via `cargo` overrides the local installation,
even if it has a higher version.
This is problematic if we want to test the LSP server inside VSCode, so
now there option in settings to disable autoupdate.

Author: gerau

vscode/package.json

@@ -67,6 +67,11 @@
           "type": "boolean",
           "default": false,
           "description": "Do not show missing LSP executable warning."
+        },
+        "simplicityhl.disableAutoupdate": {
+          "type": "boolean",
+          "default": false,
+          "description": "Do not autoupdate LSP server."
         }
       }
     },

vscode/src/find_server.ts

@@ -109,12 +109,17 @@ export async function ensureExecutable(
   const cargoPath = findExecutable("cargo");
   const config = workspace.getConfiguration("simplicityhl");
 
-  const suppressWarning = config.get<boolean>(
-    "suppressMissingLspWarning",
-    false,
-  );
+  let serverPath = findExecutable(command);
+
+  if (!cargoPath && !serverPath) {
+    const suppressWarning = config.get<boolean>(
+      "suppressMissingLspWarning",
+      false,
+    );
+    if (suppressWarning) {
+      return null;
+    }
 
-  if (!cargoPath && !suppressWarning) {
     const choice = await window.showWarningMessage(
       `To use SimplicityHL language server, please install cargo`,
       "Learn more",
@@ -133,12 +138,21 @@ export async function ensureExecutable(
   }
 
   if (cargoPath) {
-    try {
-      await installServer(command);
-      return findExecutable(command);
-    } catch (err) {
-      window.showErrorMessage(err);
-      return null;
+    const disableAutoupdate = config.get<boolean>("disableAutoupdate", false);
+
+    const shouldInstallOrUpdate = (!serverPath) || !disableAutoupdate;
+
+    if (shouldInstallOrUpdate) {
+      try {
+        await installServer(command);
+
+        serverPath = findExecutable(command);
+      } catch (err) {
+        window.showErrorMessage(err);
+        return null;
+      }
     }
   }
+
+  return serverPath;
 }