add logic to allow ISO 8601 duration strings

packages/snaps-rpc-methods/src/permitted/scheduleBackgroundEvent.test.ts

@@ -120,6 +120,54 @@ describe('snap_scheduleBackgroundEvent', () => {
       });
     });
 
+    it('schedules a background event using duration', async () => {
+      const { implementation } = scheduleBackgroundEventHandler;
+
+      const scheduleBackgroundEvent = jest.fn();
+      const hasPermission = jest.fn().mockImplementation(() => true);
+
+      const hooks = {
+        scheduleBackgroundEvent,
+        hasPermission,
+      };
+
+      const engine = new JsonRpcEngine();
+
+      engine.push(createOriginMiddleware(MOCK_SNAP_ID));
+      engine.push((request, response, next, end) => {
+        const result = implementation(
+          request as JsonRpcRequest<ScheduleBackgroundEventParams>,
+          response as PendingJsonRpcResponse<ScheduleBackgroundEventResult>,
+          next,
+          end,
+          hooks,
+        );
+
+        result?.catch(end);
+      });
+
+      await engine.handle({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'snap_scheduleBackgroundEvent',
+        params: {
+          date: 'PT30S',
+          request: {
+            method: 'handleExport',
+            params: ['p1'],
+          },
+        },
+      });
+
+      expect(scheduleBackgroundEvent).toHaveBeenCalledWith({
+        date: expect.any(String),
+        request: {
+          method: 'handleExport',
+          params: ['p1'],
+        },
+      });
+    });
+
     it('throws if a snap does not have the "endowment:cronjob" permission', async () => {
       const { implementation } = scheduleBackgroundEventHandler;
 

packages/snaps-rpc-methods/src/permitted/scheduleBackgroundEvent.ts

@@ -19,7 +19,7 @@ import {
   string,
 } from '@metamask/superstruct';
 import { assert, type PendingJsonRpcResponse } from '@metamask/utils';
-import { DateTime } from 'luxon';
+import { DateTime, Duration } from 'luxon';
 
 import { SnapEndowments } from '../endowments';
 import type { MethodHooksObject } from '../utils';
@@ -58,12 +58,15 @@ const offsetRegex = /Z|([+-]\d{2}:?\d{2})$/u;
 const ScheduleBackgroundEventsParametersStruct = object({
   date: refine(string(), 'date', (val) => {
     const date = DateTime.fromISO(val);
+    const duration = Duration.fromISO(val);
     if (date.isValid) {
       // Luxon doesn't have a reliable way to check if timezone info was not provided
       if (!offsetRegex.test(val)) {
         return 'ISO 8601 string must have timezone information';
       }
       return true;
+    } else if (duration.isValid) {
+      return true;
     }
     return 'Not a valid ISO 8601 string';
   }),
@@ -109,12 +112,22 @@ async function getScheduleBackgroundEventImplementation(
 
     const { date, request } = validatedParams;
 
+    let truncatedDate;
+
+    const duration = Duration.fromISO(date);
+
+    // We have to check if the string is a duration or not
+    if (duration.isValid) {
+      truncatedDate = DateTime.fromJSDate(new Date()).toUTC().plus(duration);
+    } else {
+      truncatedDate = DateTime.fromISO(date, { setZone: true });
+    }
+
     // Make sure any millisecond precision is removed.
-    const truncatedDate = DateTime.fromISO(date, { setZone: true })
-      .startOf('second')
-      .toISO({
-        suppressMilliseconds: true,
-      });
+
+    truncatedDate = truncatedDate.startOf('second').toISO({
+      suppressMilliseconds: true,
+    });
 
     assert(truncatedDate);
 

packages/snaps-sdk/src/types/methods/schedule-background-event.ts

@@ -3,7 +3,9 @@ import type { Cronjob } from '../permissions';
 /**
  * The request parameters for the `snap_scheduleBackgroundEvent` method.
  *
- * @property date - The ISO8601 date of when to fire the background event.
+ * Note: The date generated from a duration will be represented in UTC.
+ *
+ * @property date - The ISO 8601 date/duration of when to fire the background event.
  * @property request - The request to be called when the event fires.
  */
 export type ScheduleBackgroundEventParams = {