Go back to using promises (which still return abort method) and updat…

…e test

src/core/server/elasticsearch/cluster_client.test.ts

@@ -165,15 +165,23 @@ describe('#callAsInternalUser', () => {
     ).rejects.toStrictEqual(mockAuthenticationError);
   });
 
-  test('sets the onabort property of a signal if provided', () => {
+  test('aborts the request and rejects if a signal is provided and aborted', async () => {
     const controller = new AbortController();
 
-    clusterClient.callAsInternalUser('ping', undefined, {
+    // The ES client returns a promise with an additional `abort` method to abort the request
+    const mockValue: any = Promise.resolve();
+    mockValue.abort = jest.fn();
+    mockEsClientInstance.ping.mockReturnValue(mockValue);
+
+    const promise = clusterClient.callAsInternalUser('ping', undefined, {
       wrap401Errors: false,
       signal: controller.signal,
     });
 
-    expect(typeof controller.signal.onabort).toBe('function');
+    controller.abort();
+
+    expect(mockValue.abort).toHaveBeenCalled();
+    await expect(promise).rejects.toThrowErrorMatchingInlineSnapshot(`"Request was aborted"`);
   });
 
   test('does not override WWW-Authenticate if returned by Elasticsearch', async () => {

src/core/server/elasticsearch/cluster_client.ts

@@ -71,14 +71,14 @@ async function callAPI(
   const apiContext = clientPath.length === 1 ? client : get(client, clientPath.slice(0, -1));
   try {
     return await new Promise((resolve, reject) => {
-      // We have to use a callback here instead of using promises directly because it's the only way
-      // to get access to the abort method on the request
-      const request = api.call(apiContext, clientParams, (err: any, res: any) =>
-        err ? reject(err) : resolve(res)
-      );
+      const request = api.call(apiContext, clientParams);
       if (options.signal) {
-        options.signal.onabort = () => request.abort();
+        options.signal.addEventListener('abort', () => {
+          request.abort();
+          reject(new Error('Request was aborted'));
+        });
       }
+      return request.then(resolve, reject);
     });
   } catch (err) {
     if (!options.wrap401Errors || err.statusCode !== 401) {