Add an error utility for messages and status codes

languageserver/package.json

@@ -43,6 +43,7 @@
     "@github/actions-languageservice": "^0.1.167",
     "@github/actions-workflow-parser": "^0.1.167",
     "@octokit/rest": "^19.0.7",
+    "@octokit/types": "^9.0.0",
     "vscode-languageserver": "^8.0.2",
     "vscode-languageserver-textdocument": "^1.0.7",
     "yaml": "^2.1.3"
@@ -62,4 +63,4 @@
     "ts-jest": "^29.0.3",
     "typescript": "^4.8.4"
   }
-}
+}

languageserver/src/utils/error.ts

@@ -0,0 +1,27 @@
+import {RequestError} from "@octokit/types";
+
+export function errorMessage(error: unknown): string {
+  if (error instanceof Error) {
+    return error.message;
+  }
+  if (typeof error === "string") {
+    return error;
+  }
+
+  if ("name" in (error as RequestError)) {
+    return (error as RequestError).name;
+  }
+
+  const status = errorStatus(error);
+  if (status) {
+    return `HTTP ${status}`;
+  }
+
+  return "Unknown error";
+}
+
+export function errorStatus(error: unknown): number | undefined {
+  if ("status" in (error as RequestError)) {
+    return (error as RequestError).status;
+  }
+}