fix(sse): cleanup when app-level retries are exhausted to prevent memory leak

Co-authored-by: JavanPoirier <42590458+JavanPoirier@users.noreply.github.com>

Author: Copilot

.changeset/fix-sse-cleanup-on-retries-exhausted.md

@@ -0,0 +1,5 @@
+---
+"@solid-primitives/sse": patch
+---
+
+Fix memory leak when app-level retries are exhausted in `createSSE`. Previously, when all reconnect attempts were used up and the `EventSource` was permanently closed, `currentCleanup` was never called — leaving the `EventSource` instance and its event listeners alive in memory, and the `source` signal pointing to a stale handle. Now an `else if` branch explicitly calls `currentCleanup()`, clears the reference, and sets the `source` signal to `undefined`.

packages/sse/src/sse.ts

@@ -260,6 +260,11 @@ export const createSSE = <T = string>(
       if (es.readyState === SSEReadyState.CLOSED && retriesLeft > 0) {
         retriesLeft--;
         reconnectTimer = setTimeout(() => _open(resolvedUrl), reconnectConfig.delay ?? 3000);
+      } else if (es.readyState === SSEReadyState.CLOSED) {
+        // Retries exhausted — clean up fully to avoid memory/listener leaks.
+        currentCleanup?.();
+        currentCleanup = undefined;
+        setSource(undefined);
       }
     };
 

packages/sse/test/index.test.ts

@@ -181,12 +181,31 @@ describe("createSSE", () => {
       const first = source();
       (first as unknown as MockEventSource).simulateError();
       vi.advanceTimersByTime(100); // first retry
-      const second = source();
+      const second = source() as unknown as MockEventSource;
       expect(second).not.toBe(first);
       vi.advanceTimersByTime(20); // second opens
-      (second as unknown as MockEventSource).simulateError();
+      const closeSpy = vi.spyOn(second, "close");
+      second.simulateError();
       vi.advanceTimersByTime(200); // no more retries
-      expect(source()).toBe(second); // still the same source
+      // retries exhausted: close() was called and source signal is cleared
+      expect(closeSpy).toHaveBeenCalledOnce();
+      expect(source()).toBeUndefined();
+      dispose();
+    }));
+
+  it("cleans up source and listeners when retries are exhausted", () =>
+    createRoot(dispose => {
+      const { source, readyState } = createSSE("https://example.com/events", {
+        reconnect: { retries: 0, delay: 50 },
+      });
+      vi.advanceTimersByTime(20);
+      const es = source() as unknown as MockEventSource;
+      const closeSpy = vi.spyOn(es, "close");
+      es.simulateError();
+      // retries exhausted immediately — cleanup must have run
+      expect(closeSpy).toHaveBeenCalledOnce();
+      expect(source()).toBeUndefined();
+      expect(readyState()).toBe(SSEReadyState.CLOSED);
       dispose();
     }));