fix(state-pg): setIfNotExists TTL expiry

.changeset/state-pg-set-if-not-exists-ttl.md

@@ -0,0 +1,5 @@
+---
+"@chat-adapter/state-pg": patch
+---
+
+Fix `setIfNotExists()` so it can claim a cache key whose existing row has expired. Previously the query used `ON CONFLICT DO NOTHING`, so an expired row in `chat_state_cache` still blocked acquisition until opportunistic cleanup deleted it — diverging from the memory and Redis adapters, which treat expired entries as absent. Keys stored without a TTL remain permanent and are never overwritten.

packages/state-pg/src/index.test.ts

@@ -439,6 +439,20 @@ describe("PostgresStateAdapter", () => {
         expect(result).toBe(true);
       });
 
+      it("should allow setIfNotExists to replace expired keys", async () => {
+        queryRows = [{ cache_key: "key" }];
+        const result = await adapter.setIfNotExists("key", "value", 5000);
+
+        expect(result).toBe(true);
+        expect(pool.query).toHaveBeenCalledWith(
+          expect.stringContaining(
+            `WHERE chat_state_cache.expires_at IS NOT NULL
+           AND chat_state_cache.expires_at <= now()`
+          ),
+          ["chat-sdk", "key", '"value"', expect.any(Date)]
+        );
+      });
+
       it("should delete a value without throwing", async () => {
         await adapter.delete("key");
       });

packages/state-pg/src/index.ts

@@ -260,7 +260,12 @@ export class PostgresStateAdapter implements StateAdapter {
     const result = await this.pool.query(
       `INSERT INTO chat_state_cache (key_prefix, cache_key, value, expires_at)
        VALUES ($1, $2, $3, $4)
-       ON CONFLICT (key_prefix, cache_key) DO NOTHING
+       ON CONFLICT (key_prefix, cache_key) DO UPDATE
+         SET value = EXCLUDED.value,
+             expires_at = EXCLUDED.expires_at,
+             updated_at = now()
+         WHERE chat_state_cache.expires_at IS NOT NULL
+           AND chat_state_cache.expires_at <= now()
        RETURNING cache_key`,
       [this.keyPrefix, key, serialized, expiresAt]
     );