fix: preserve error cause in getHostAddress() for better debugging

The getHostAddress() method in DurableTaskAzureManagedClientOptions drops the
original URL parsing error when re-throwing, making it difficult to debug why
a specific endpoint URL is invalid. This change preserves the original error
as the cause property of the new Error.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Copilot

packages/durabletask-js-azuremanaged/src/options.ts

@@ -101,8 +101,8 @@ abstract class DurableTaskAzureManagedOptionsBase {
         authority = `${authority}:${url.port}`;
       }
       return authority;
-    } catch {
-      throw new Error(`Invalid endpoint URL: ${endpoint}`);
+    } catch (e) {
+      throw new Error(`Invalid endpoint URL: ${endpoint}`, { cause: e });
     }
   }
 

packages/durabletask-js-azuremanaged/test/unit/options.spec.ts

@@ -158,6 +158,23 @@ describe("Options", () => {
 
         expect(() => options.getHostAddress()).toThrow("Invalid endpoint URL:");
       });
+
+      it("should preserve the original error as cause when URL parsing fails", () => {
+        const options = new DurableTaskAzureManagedClientOptions().setEndpointAddress("invalid:url");
+
+        try {
+          options.getHostAddress();
+          fail("Expected getHostAddress to throw");
+        } catch (e: unknown) {
+          expect(e).toBeInstanceOf(Error);
+          const error = e as Error;
+          expect(error.message).toContain("Invalid endpoint URL:");
+          expect(error.cause).toBeDefined();
+          // The cause should be the original URL parsing error
+          expect((error.cause as Error).message).toBeDefined();
+          expect((error.cause as Error).message.length).toBeGreaterThan(0);
+        }
+      });
     });
 
     describe("createChannelCredentials", () => {