fix(core): evaluate nested $exists filters under missing parents

eventFilterMatches returned false for any non-empty filter as soon as the payload was undefined or null, before the filter itself was evaluated. That made a nested $exists: false filter fail when a parent key was absent or null, even though a missing child is exactly what $exists: false asserts. Reachable through retry.fetch bodyFilter on response bodies.

Author: princejain756

.changeset/nested-exists-filter.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/core": patch
+---
+
+Fix `bodyFilter` in `retry.fetch` not matching when a nested `$exists: false` filter sits under a parent key that is missing or null in the response body.

packages/core/src/eventFilterMatches.ts

@@ -6,11 +6,9 @@ import type { EventFilter } from "./schemas/eventFilter.js";
 // An example would be [{ $endsWith: ".png" }, { $startsWith: "images/" } ]
 export function eventFilterMatches(payload: any, filter: EventFilter): boolean {
   if (payload === undefined || payload === null) {
-    if (Object.entries(filter).length === 0) {
-      return true;
-    } else {
-      return false;
-    }
+    // A missing or null payload means none of its keys exist either, so the
+    // filter still has to be evaluated: { a: [{ $exists: false }] } must match.
+    payload = {};
   }
 
   for (const [patternKey, patternValue] of Object.entries(filter)) {

packages/core/test/eventFilterMatches.test.ts

@@ -209,6 +209,18 @@ describe("eventFilterMatches", () => {
     expect(eventFilterMatches(payload, filter)).toBe(true);
   });
 
+  it("should return true for nested $exists = false when the parent key is missing or null", () => {
+    const filter: EventFilter = {
+      user: {
+        email: [{ $exists: false }],
+      },
+    };
+    expect(eventFilterMatches({}, filter)).toBe(true);
+    expect(eventFilterMatches({ user: null }, filter)).toBe(true);
+    expect(eventFilterMatches({ user: {} }, filter)).toBe(true);
+    expect(eventFilterMatches({ user: { email: "a@example.com" } }, filter)).toBe(false);
+  });
+
   it("should return true when payload does match numeric condition", () => {
     const payload = {
       name: "John",