fix: ensure assignee is checked in userUnassigned handler

Check `assignee` before closing pull requests to avoid errors.

src/handlers/user-start-stop.ts

@@ -92,13 +92,18 @@ export async function userPullRequest(context: Context<"pull_request.opened" | "
   return { status: HttpStatusCode.NOT_MODIFIED };
 }
 
-export async function userUnassigned(context: Context): Promise<Result> {
+export async function userUnassigned(context: Context<"issues.unassigned">): Promise<Result> {
   if (!("issue" in context.payload)) {
     context.logger.debug("Payload does not contain an issue, skipping issues.unassigned event.");
     return { status: HttpStatusCode.NOT_MODIFIED };
   }
   const { payload } = context;
-  const { issue, sender, repository } = payload;
-  await closePullRequestForAnIssue(context, issue.number, repository, sender.login);
+  const { issue, repository, assignee } = payload;
+  // 'assignee' is the user that actually got un-assigned during this event. Since it can theoretically be null,
+  // we display an error if none is found in the payload.
+  if (!assignee) {
+    throw context.logger.fatal("No assignee found in payload, failed to close pull-requests.");
+  }
+  await closePullRequestForAnIssue(context, issue.number, repository, assignee?.login);
   return { status: HttpStatusCode.OK, content: "Linked pull-requests closed." };
 }

src/plugin.ts

@@ -35,7 +35,7 @@ export async function startStopTask(inputs: PluginInputs, env: Env) {
       case "pull_request.edited":
         return await userPullRequest(context as Context<"pull_request.edited">);
       case "issues.unassigned":
-        return await userUnassigned(context);
+        return await userUnassigned(context as Context<"issues.unassigned">);
       default:
         context.logger.error(`Unsupported event: ${context.eventName}`);
     }

tests/main.test.ts

@@ -622,6 +622,9 @@ export function createContext(
       action: "created",
       installation: { id: 1 } as unknown as Context["payload"]["installation"],
       organization: { login: "ubiquity" } as unknown as Context["payload"]["organization"],
+      assignee: {
+        ...sender,
+      },
     } as Context["payload"],
     logger: new Logs("debug"),
     config: {