fix: preserve pixel safety target context

tests/unit/agents/test_precondition_pixel_target.py

@@ -0,0 +1,100 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for pixel safety-net target descriptions."""
+
+from pathlib import Path
+from unittest.mock import MagicMock
+
+from artemis.agents.validator import precondition_pixel as pp
+from langchain_core.messages import HumanMessage, SystemMessage
+
+_PNG = b"fake-image-bytes"
+
+
+def _texts(messages: list) -> list[str]:
+    human = messages[1]
+    return [part["text"] for part in human.content if part["type"] == "text"]
+
+
+def test_named_control_target_block_precedes_images():
+    item = {
+        "action": "tap",
+        "coordinates": [1001, 718],
+        "target_text": "进入全屏模式",
+        "target_resource_id": "com.google.android.youtube:id/fullscreen_button",
+        "target_class": "android.widget.ImageView",
+        "target_bounds": [922, 655, 1080, 781],
+    }
+    state = MagicMock()
+    state.operator_native_thinking = "identified 进入全屏模式"
+    state.operator_raw_thinking = None
+
+    messages = pp._build_messages("SYSTEM", _PNG, _PNG, item, state)
+
+    assert isinstance(messages[0], SystemMessage)
+    assert isinstance(messages[1], HumanMessage)
+    first_text = messages[1].content[0]["text"]
+    assert first_text.startswith("[Target]")
+    assert "Kind: specific UI control" in first_text
+    assert "Label: 进入全屏模式" in first_text
+    assert "Resource ID: com.google.android.youtube:id/fullscreen_button" in first_text
+    assert "Class: android.widget.ImageView" in first_text
+    assert "[922, 655, 1080, 781]" in first_text
+    assert messages[1].content[1]["text"] == "[Image 1 (Reference)]"
+    assert any("Original Thinking" in t for t in _texts(messages))
+    assert any("Action: tap" in t for t in _texts(messages))
+
+
+def test_coordinates_only_target_is_labelled_as_surface():
+    item = {"action": "tap", "coordinates": [540, 400]}
+
+    messages = pp._build_messages("SYSTEM", _PNG, _PNG, item, state=None)
+
+    first_text = messages[1].content[0]["text"]
+    assert "Kind: coordinates only" in first_text
+    assert "Label:" not in first_text
+    assert "Resource ID:" not in first_text
+    assert not any("Original Thinking" in t for t in _texts(messages))
+
+
+def test_label_alone_counts_as_named_control():
+    item = {"action": "tap", "coordinates": [10, 10], "target_text": "Submit"}
+    text = pp._describe_target(item)
+    assert "Kind: specific UI control" in text
+    assert "Label: Submit" in text
+    assert "Resource ID" not in text
+
+
+def test_unlabelled_hit_test_element_is_still_a_control():
+    item = {
+        "action": "tap",
+        "coordinates": [1001, 718],
+        "target_class": "android.widget.ImageView",
+        "target_bounds": [922, 655, 1080, 781],
+        "target_label_source": "hit_test",
+    }
+    text = pp._describe_target(item)
+    assert "Kind: specific UI control" in text
+    assert "unlabelled" in text
+    assert "Class: android.widget.ImageView" in text
+    assert "[922, 655, 1080, 781]" in text
+
+
+def test_prompt_rules_are_keyed_on_target_kind():
+    prompt = Path(pp.__file__).with_name("pixel_safety_net.md").read_text(encoding="utf-8")
+    assert "`Kind: specific UI control`" in prompt
+    assert "`Kind: coordinates only`" in prompt
+    assert "hidden" in prompt
+    assert "Identify what appears under the red dot" in prompt