add missing fetchEvent type for UnknownEventNotification (#2453)

add missing fetchEvent type for UnknownThinEvent

Author: xavdid-stripe

src/stripe.core.ts

@@ -525,19 +525,21 @@ export function createStripe(
         );
       };
 
-      if (eventNotification.related_object) {
-        eventNotification.fetchRelatedObject = (): Promise<unknown> => {
-          return this._requestSender._rawRequest(
-            'GET',
-            eventNotification.related_object.url,
-            undefined,
-            {
-              stripeContext: eventNotification.context,
-            },
-            ['fetch_related_object']
-          );
-        };
-      }
+      eventNotification.fetchRelatedObject = (): Promise<unknown> => {
+        if (!eventNotification.related_object) {
+          return Promise.resolve(null);
+        }
+
+        return this._requestSender._rawRequest(
+          'GET',
+          eventNotification.related_object.url,
+          undefined,
+          {
+            stripeContext: eventNotification.context,
+          },
+          ['fetch_related_object']
+        );
+      };
 
       return eventNotification;
     },

test/stripe.spec.ts

@@ -802,7 +802,10 @@ describe('Stripe Module', function() {
             );
 
             expect(event.fetchEvent).to.be.a('function');
-            expect(event.fetchRelatedObject).not.to.be.a('function');
+            // this is always present, but hidden in the types if there's no object
+            // not easy to add conditionally because we don't know at runtime if we have a type for the event or not
+            expect(event.fetchRelatedObject).to.be.a('function');
+            expect(await event.fetchRelatedObject()).to.be.null;
             const pulled = await event.fetchEvent();
             expect(pulled.data).to.equal(jsonWithData.data);
             // Have to call another requests for metrics to be sent.

types/V2/EventMisc.d.ts

@@ -36,7 +36,15 @@ declare module 'stripe' {
          * Object containing the reference to API resource relevant to the event.
          */
         related_object: V2.Core.Events.RelatedObject | null;
+        /**
+         * Fetches the full object corresponding to the `related_object` field.
+         * Returns `null` if there is no `related_object`.
+         */
         fetchRelatedObject: () => Promise<unknown>;
+        /**
+         * Fetches the full Event object corresponding to this notification.
+         */
+        fetchEvent: () => Promise<V2.Core.EventBase>;
       }
     }
 

types/test/typescriptTest.ts

@@ -333,6 +333,13 @@ async (): Promise<void> => {
     // @ts-expect-error - shouldn't be available
     eventNotification.related_object;
     const e: Stripe.Events.V1BillingMeterNoMeterFoundEvent = await eventNotification.fetchEvent();
+    // @ts-expect-error - isn't a known type
+  } else if (eventNotification.type === 'some.unknown.event') {
+    const e = eventNotification as Stripe.Events.UnknownEventNotification;
+    e.fetchEvent();
+    // these exist, but may be null
+    e.related_object;
+    e.fetchRelatedObject();
   }
 };