From 387752c56e587124f22e5f1aa0decfed8aadd7e3 Mon Sep 17 00:00:00 2001
From: biefan <70761325+biefan@users.noreply.github.com>
Date: Tue, 17 Mar 2026 06:52:34 +0000
Subject: [PATCH] Return no memory results for empty prompt ID filters

---
 pyrit/memory/memory_interface.py              |  3 +++
 .../test_interface_prompts.py                 | 12 +++++++++
 .../memory_interface/test_interface_scores.py | 25 +++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/pyrit/memory/memory_interface.py b/pyrit/memory/memory_interface.py
index 90322ebec4..2faad11d36 100644
--- a/pyrit/memory/memory_interface.py
+++ b/pyrit/memory/memory_interface.py
@@ -610,6 +610,9 @@ def get_message_pieces(
             Exception: If there is an error retrieving the prompts,
                 an exception is logged and an empty list is returned.
         """
+        if prompt_ids is not None and len(prompt_ids) == 0:
+            return []
+
         conditions = []
         if attack_id:
             conditions.append(self._get_message_pieces_attack_conditions(attack_id=str(attack_id)))
diff --git a/tests/unit/memory/memory_interface/test_interface_prompts.py b/tests/unit/memory/memory_interface/test_interface_prompts.py
index 67a4292f87..53e2d0f180 100644
--- a/tests/unit/memory/memory_interface/test_interface_prompts.py
+++ b/tests/unit/memory/memory_interface/test_interface_prompts.py
@@ -108,6 +108,18 @@ def test_get_message_pieces_uuid_and_string_ids(sqlite_instance: MemoryInterface
     assert str(single_str_result[0].id) == str(uuid3)
 
 
+def test_get_message_pieces_empty_prompt_ids_returns_empty(sqlite_instance: MemoryInterface):
+    piece = MessagePiece(
+        id=uuid.uuid4(),
+        role="user",
+        original_value="Test prompt",
+        converted_value="Test prompt",
+    )
+    sqlite_instance.add_message_pieces_to_memory(message_pieces=[piece])
+
+    assert sqlite_instance.get_message_pieces(prompt_ids=[]) == []
+
+
 def test_duplicate_memory(sqlite_instance: MemoryInterface):
     attack1 = PromptSendingAttack(objective_target=get_mock_target())
     attack2 = PromptSendingAttack(objective_target=get_mock_target("Target2"))
diff --git a/tests/unit/memory/memory_interface/test_interface_scores.py b/tests/unit/memory/memory_interface/test_interface_scores.py
index 6087af1418..34358d5e93 100644
--- a/tests/unit/memory/memory_interface/test_interface_scores.py
+++ b/tests/unit/memory/memory_interface/test_interface_scores.py
@@ -131,6 +131,31 @@ def test_add_score_get_score(
     assert db_score[0].message_piece_id == prompt_id
 
 
+def test_get_prompt_scores_empty_prompt_ids_returns_empty(sqlite_instance: MemoryInterface):
+    prompt_id = uuid4()
+    piece = MessagePiece(
+        id=prompt_id,
+        role="user",
+        original_value="original prompt text",
+        converted_value="Hello, how are you?",
+    )
+    sqlite_instance.add_message_pieces_to_memory(message_pieces=[piece])
+
+    score = Score(
+        score_value=str(0.8),
+        score_value_description="High score",
+        score_type="float_scale",
+        score_category=["test"],
+        score_rationale="Test score",
+        score_metadata={"test": "metadata"},
+        scorer_class_identifier=_test_scorer_id("TestScorer"),
+        message_piece_id=prompt_id,
+    )
+    sqlite_instance.add_scores_to_memory(scores=[score])
+
+    assert sqlite_instance.get_prompt_scores(prompt_ids=[]) == []
+
+
 def test_add_score_duplicate_prompt(sqlite_instance: MemoryInterface):
     # Ensure that scores of duplicate prompts are linked back to the original
     original_id = uuid4()