From 4d19f7d92becff955de12e2a58bc6bb23f14492d Mon Sep 17 00:00:00 2001
From: Kamil Tomaszek <kamilos@google.com>
Date: Thu, 23 Jul 2026 06:32:16 -0700
Subject: [PATCH] fix(sessions): apply numRecentEvents and afterTimestamp
 together in InMemorySessionService

`getSession` applied `afterTimestamp` only when `numRecentEvents` was unset, so the two `GetSessionConfig` filters could not be combined. Apply `numRecentEvents` first, then `afterTimestamp`, so both compose. Mirrors Python and Go, which already apply both.

PiperOrigin-RevId: 952725154
---
 .../adk/sessions/InMemorySessionService.java  | 12 +++++-----
 .../sessions/InMemorySessionServiceTest.java  | 23 +++++++++++++++++++
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/core/src/main/java/com/google/adk/sessions/InMemorySessionService.java b/core/src/main/java/com/google/adk/sessions/InMemorySessionService.java
index 72a14cc4d..e54289b76 100644
--- a/core/src/main/java/com/google/adk/sessions/InMemorySessionService.java
+++ b/core/src/main/java/com/google/adk/sessions/InMemorySessionService.java
@@ -150,12 +150,12 @@ public Maybe<Session> getSession(
               }
             });
 
-    // Only apply timestamp filter if numRecentEvents was not applied
-    if (config.numRecentEvents().isEmpty() && config.afterTimestamp().isPresent()) {
-      Instant threshold = config.afterTimestamp().get();
-
-      eventsInCopy.removeIf(event -> getInstantFromEvent(event).isBefore(threshold));
-    }
+    // Then drop events before afterTimestamp, so both filters compose.
+    config
+        .afterTimestamp()
+        .ifPresent(
+            threshold ->
+                eventsInCopy.removeIf(event -> getInstantFromEvent(event).isBefore(threshold)));
 
     // Merge state into the potentially filtered copy and return
     return Maybe.just(mergeWithGlobalState(appName, userId, sessionCopy));
diff --git a/core/src/test/java/com/google/adk/sessions/InMemorySessionServiceTest.java b/core/src/test/java/com/google/adk/sessions/InMemorySessionServiceTest.java
index 6a271efac..58c445641 100644
--- a/core/src/test/java/com/google/adk/sessions/InMemorySessionServiceTest.java
+++ b/core/src/test/java/com/google/adk/sessions/InMemorySessionServiceTest.java
@@ -317,4 +317,27 @@ public void deleteSession_doesNotRemoveUserMapWhenOtherSessionsExist() throws Ex
     assertThat(sessions.get("app-name").get("user-id")).isNotNull();
     assertThat(sessions.get("app-name").get("user-id")).hasSize(1);
   }
+
+  @Test
+  public void getSession_numRecentEventsAndAfterTimestamp_appliesBothFilters() {
+    InMemorySessionService sessionService = new InMemorySessionService();
+    Session session = sessionService.createSession("app", "user").blockingGet();
+    for (long ts : new long[] {100, 200, 300, 400, 500}) {
+      var unused =
+          sessionService.appendEvent(session, Event.builder().timestamp(ts).build()).blockingGet();
+    }
+    GetSessionConfig config =
+        GetSessionConfig.builder()
+            .numRecentEvents(4)
+            .afterTimestamp(Instant.ofEpochMilli(300))
+            .build();
+
+    Session retrieved =
+        sessionService.getSession("app", "user", session.id(), Optional.of(config)).blockingGet();
+
+    // numRecentEvents keeps 200..500, then afterTimestamp drops 200; the pre-fix code kept 200.
+    assertThat(retrieved.events().stream().map(Event::timestamp))
+        .containsExactly(300L, 400L, 500L)
+        .inOrder();
+  }
 }