Files
turnstone/tests/test_session.py
T
Patrick Buckley 6cc1b3a5bd feat: add vision/image support to read_file tool (#33)
* feat: add vision/image support to read_file tool

read_file now detects image files (PNG, JPEG, GIF, WebP, BMP, TIFF, ICO)
and returns base64-encoded content parts for vision-capable models.
Non-vision models receive a text description instead. A new
supports_vision flag on ModelCapabilities gates the feature, with
config.toml [models.*.capabilities] overrides for local models
(vLLM, llama.cpp, NIM).

* fix: address PR review feedback

- Discard _read_files on no-vision OSError path, include exception detail
- Discard _read_files on oversized image error (not a successful read)
- Validate capabilities type from config.toml (reject non-dict)
- Clarify tool description re: vision behavior and offset/limit scope
- Remove unused os import in tests, fix import sort order
- Handle list content (image tool results) in eval.py tool result loop
2026-03-08 23:43:42 -07:00

420 lines
15 KiB
Python

"""Tests for turnstone.core.session — ChatSession construction."""
import base64
import json
from unittest.mock import MagicMock, patch
from turnstone.core.session import _IMAGE_EXTENSIONS, _IMAGE_SIZE_CAP, ChatSession
class NullUI:
"""UI adapter that discards all output. Used for testing."""
def on_thinking_start(self):
pass
def on_thinking_stop(self):
pass
def on_reasoning_token(self, text):
pass
def on_content_token(self, text):
pass
def on_stream_end(self):
pass
def approve_tools(self, items):
return True, None
def on_tool_result(self, call_id, name, output):
pass
def on_tool_output_chunk(self, call_id, chunk):
pass
def on_status(self, usage, context_window, effort):
pass
def on_plan_review(self, content):
return ""
def on_info(self, message):
pass
def on_error(self, message):
pass
def on_state_change(self, state):
pass
def on_rename(self, name):
pass
def _make_session(
mock_openai_client=None,
instructions=None,
**kwargs,
):
"""Helper to construct a ChatSession with minimal setup."""
client = mock_openai_client or MagicMock()
defaults = dict(
client=client,
model="test-model",
ui=NullUI(),
instructions=instructions,
temperature=0.5,
max_tokens=4096,
tool_timeout=30,
)
defaults.update(kwargs)
return ChatSession(**defaults)
class TestChatSessionConstruction:
def test_system_messages_created(self, tmp_db):
session = _make_session()
assert len(session.system_messages) >= 1
# At least one system message
roles = [m["role"] for m in session.system_messages]
assert "system" in roles
def test_instructions_appended_to_system_message(self, tmp_db):
session = _make_session(instructions="Always be concise.")
sys_msgs = [m for m in session.system_messages if m["role"] == "system"]
assert len(sys_msgs) >= 1
assert "Always be concise." in sys_msgs[0]["content"]
def test_full_messages_returns_system_plus_conversation(self, tmp_db):
session = _make_session()
# Initially no conversation messages
full = session._full_messages()
assert len(full) == len(session.system_messages)
# Add a user message
session.messages.append({"role": "user", "content": "hello"})
full = session._full_messages()
assert len(full) == len(session.system_messages) + 1
assert full[-1]["role"] == "user"
def test_msg_char_count_content_only(self, tmp_db):
session = _make_session()
msg = {"role": "assistant", "content": "hello world"}
assert session._msg_char_count(msg) == 11
def test_msg_char_count_with_tool_calls(self, tmp_db):
session = _make_session()
msg = {
"role": "assistant",
"content": "hi",
"tool_calls": [
{
"id": "tc_1",
"function": {
"name": "bash",
"arguments": '{"command": "ls"}',
},
}
],
}
# "hi" (2) + "bash" (4) + '{"command": "ls"}' (17) = 23
assert session._msg_char_count(msg) == 23
def test_msg_char_count_none_content(self, tmp_db):
session = _make_session()
msg = {"role": "assistant", "content": None}
assert session._msg_char_count(msg) == 0
def test_reasoning_effort_stored(self, tmp_db):
session = _make_session(reasoning_effort="high")
assert session.reasoning_effort == "high"
def test_default_reasoning_effort(self, tmp_db):
session = _make_session()
assert session.reasoning_effort == "medium"
# ---------------------------------------------------------------------------
# Tests — _exec_plan (session-scoped plan files + existing-plan re-read)
# ---------------------------------------------------------------------------
class TestPlanExec:
"""Tests for _exec_plan: unique session-scoped plan file and existing-plan injection."""
def _run_plan(self, session, prompt, agent_return="# Plan\n\nDo the thing."):
"""Invoke _exec_plan with _run_agent patched to avoid LLM calls.
Returns (call_id_returned, content_returned, captured_messages) where
captured_messages is the agent_messages list passed to _run_agent.
"""
captured = {}
def fake_run_agent(messages, **kwargs):
captured["messages"] = list(messages)
return agent_return
item = {"call_id": "test-call-1", "prompt": prompt}
with patch.object(session, "_run_agent", side_effect=fake_run_agent):
call_id, content = session._exec_plan(item)
return call_id, content, captured.get("messages", [])
def test_plan_file_uses_ws_id(self, tmp_db, tmp_path, monkeypatch):
"""Plan file is named .plan-<ws_id>.md, not .plan.md."""
monkeypatch.chdir(tmp_path)
session = _make_session()
self._run_plan(session, "add feature")
expected = tmp_path / f".plan-{session._ws_id}.md"
assert expected.exists(), f"Expected {expected} to be created"
assert not (tmp_path / ".plan.md").exists()
def test_plan_file_contains_agent_output(self, tmp_db, tmp_path, monkeypatch):
"""Written plan file contains the agent's output verbatim."""
monkeypatch.chdir(tmp_path)
session = _make_session()
plan_content = "## Goal\n\nAdd a new endpoint."
self._run_plan(session, "add endpoint", agent_return=plan_content)
plan_file = tmp_path / f".plan-{session._ws_id}.md"
assert plan_file.read_text() == plan_content
def test_two_sessions_produce_different_files(self, tmp_db, tmp_path, monkeypatch):
"""Two ChatSession instances never collide on the same plan file."""
monkeypatch.chdir(tmp_path)
s1 = _make_session()
s2 = _make_session()
assert s1._ws_id != s2._ws_id
self._run_plan(s1, "feature A")
self._run_plan(s2, "feature B")
files = list(tmp_path.glob(".plan-*.md"))
assert len(files) == 2
def _seed_prior_plan(self, session, prior_prompt, prior_content):
"""Simulate a completed plan tool call in session.messages."""
tc_id = "call_prior_plan"
session.messages.append(
{
"role": "assistant",
"content": None,
"tool_calls": [
{
"id": tc_id,
"type": "function",
"function": {
"name": "plan",
"arguments": json.dumps({"prompt": prior_prompt}),
},
}
],
}
)
session.messages.append(
{
"role": "tool",
"tool_call_id": tc_id,
"content": prior_content,
}
)
def test_no_prior_plan_no_extra_messages(self, tmp_db, tmp_path, monkeypatch):
"""First invocation: no prior plan in history, agent gets no tool pair."""
monkeypatch.chdir(tmp_path)
session = _make_session()
_, _, messages = self._run_plan(session, "build something")
roles = [m["role"] for m in messages]
assert "tool" not in roles
def test_prior_plan_from_messages_injected(self, tmp_db, tmp_path, monkeypatch):
"""Second invocation: prior plan from session.messages arrives as real tool result."""
monkeypatch.chdir(tmp_path)
session = _make_session()
self._seed_prior_plan(session, "build feature X", "## Goal\n\nOriginal plan.")
_, _, messages = self._run_plan(session, "also handle edge case Y")
# The real assistant tool_calls message is forwarded
assistant_with_tc = [
m for m in messages if m["role"] == "assistant" and m.get("tool_calls")
]
assert len(assistant_with_tc) == 1
assert assistant_with_tc[0]["tool_calls"][0]["function"]["name"] == "plan"
# The real tool result is forwarded with its original content
tool_msgs = [m for m in messages if m["role"] == "tool"]
assert len(tool_msgs) == 1
assert "Original plan." in tool_msgs[0]["content"]
def test_prior_plan_appears_before_user_prompt(self, tmp_db, tmp_path, monkeypatch):
"""The prior plan tool pair appears before the new user prompt."""
monkeypatch.chdir(tmp_path)
session = _make_session()
self._seed_prior_plan(session, "original", "Old plan.")
_, _, messages = self._run_plan(session, "refinement prompt")
tool_idx = next(i for i, m in enumerate(messages) if m["role"] == "tool")
user_idx = next(i for i, m in enumerate(messages) if m["role"] == "user")
assert tool_idx < user_idx
def test_exec_plan_returns_content(self, tmp_db, tmp_path, monkeypatch):
"""_exec_plan returns (call_id, agent_output)."""
monkeypatch.chdir(tmp_path)
session = _make_session()
agent_output = "## Goal\n\nBuild it."
call_id, content, _ = self._run_plan(session, "do stuff", agent_return=agent_output)
assert call_id == "test-call-1"
assert content == agent_output
# ---------------------------------------------------------------------------
# Vision / image support
# ---------------------------------------------------------------------------
class TestImageExtensions:
"""Test _IMAGE_EXTENSIONS constant and detection logic."""
def test_common_image_extensions(self):
for ext in (".png", ".jpg", ".jpeg", ".gif", ".webp", ".bmp", ".tiff", ".tif", ".ico"):
assert ext in _IMAGE_EXTENSIONS, f"{ext} should be in _IMAGE_EXTENSIONS"
def test_svg_excluded(self):
assert ".svg" not in _IMAGE_EXTENSIONS
def test_text_extensions_excluded(self):
for ext in (".py", ".txt", ".json", ".md", ".rs", ".go"):
assert ext not in _IMAGE_EXTENSIONS
class TestExecReadImage:
"""Test _exec_read_image method."""
def _make_png(self, path: str, size: int = 100) -> None:
"""Write a minimal valid-ish PNG header to a file."""
# 8-byte PNG signature + enough bytes to reach target size
header = b"\x89PNG\r\n\x1a\n"
with open(path, "wb") as f:
f.write(header + b"\x00" * max(0, size - len(header)))
def test_image_returns_content_parts(self, tmp_db, tmp_path):
"""read_file on a PNG with vision support returns content parts."""
img = tmp_path / "test.png"
self._make_png(str(img))
session = _make_session()
# Mock provider to report vision support
mock_caps = MagicMock()
mock_caps.supports_vision = True
session._provider.get_capabilities = MagicMock(return_value=mock_caps)
item = {"call_id": "c1", "path": str(img), "offset": None, "limit": None}
call_id, output = session._exec_read_file(item)
assert call_id == "c1"
assert isinstance(output, list)
assert len(output) == 2
assert output[0]["type"] == "text"
assert "test.png" in output[0]["text"]
assert output[1]["type"] == "image_url"
url = output[1]["image_url"]["url"]
assert url.startswith("data:image/png;base64,")
# Verify base64 round-trip
b64part = url.split(",", 1)[1]
decoded = base64.b64decode(b64part)
assert decoded == img.read_bytes()
def test_no_vision_returns_text(self, tmp_db, tmp_path):
"""read_file on image with non-vision model returns text description."""
img = tmp_path / "photo.jpg"
self._make_png(str(img), size=2048)
session = _make_session()
mock_caps = MagicMock()
mock_caps.supports_vision = False
session._provider.get_capabilities = MagicMock(return_value=mock_caps)
item = {"call_id": "c2", "path": str(img), "offset": None, "limit": None}
call_id, output = session._exec_read_file(item)
assert call_id == "c2"
assert isinstance(output, str)
assert "does not support vision" in output
assert "photo.jpg" in output
def test_oversized_image_returns_error(self, tmp_db, tmp_path):
"""Images exceeding _IMAGE_SIZE_CAP return an error string."""
img = tmp_path / "huge.png"
# Write slightly over the cap
with open(img, "wb") as f:
f.write(b"\x89PNG\r\n\x1a\n" + b"\x00" * _IMAGE_SIZE_CAP)
session = _make_session()
mock_caps = MagicMock()
mock_caps.supports_vision = True
session._provider.get_capabilities = MagicMock(return_value=mock_caps)
item = {"call_id": "c3", "path": str(img), "offset": None, "limit": None}
call_id, output = session._exec_read_file(item)
assert call_id == "c3"
assert isinstance(output, str)
assert "exceeds" in output
def test_missing_image_returns_error(self, tmp_db, tmp_path):
"""read_file on non-existent image returns error."""
session = _make_session()
mock_caps = MagicMock()
mock_caps.supports_vision = True
session._provider.get_capabilities = MagicMock(return_value=mock_caps)
item = {"call_id": "c4", "path": str(tmp_path / "nope.png"), "offset": None, "limit": None}
call_id, output = session._exec_read_file(item)
assert isinstance(output, str)
assert "not found" in output
def test_svg_read_as_text(self, tmp_db, tmp_path):
"""SVG files are read as text, not as images."""
svg = tmp_path / "icon.svg"
svg.write_text('<svg xmlns="http://www.w3.org/2000/svg"><circle r="10"/></svg>')
session = _make_session()
item = {"call_id": "c5", "path": str(svg), "offset": None, "limit": None}
call_id, output = session._exec_read_file(item)
assert isinstance(output, str)
assert "<svg" in output # Read as text
class TestGetCapabilitiesOverride:
"""Test _get_capabilities with config.toml overrides."""
def test_config_override_applies(self, tmp_db):
"""capabilities dict from ModelConfig is merged onto provider caps."""
from turnstone.core.model_registry import ModelConfig, ModelRegistry
from turnstone.core.providers._protocol import ModelCapabilities
cfg = ModelConfig(
alias="qwen-vl",
base_url="http://localhost:8000/v1",
api_key="dummy",
model="qwen-3.5-vl",
capabilities={"supports_vision": True},
)
registry = ModelRegistry(
models={"qwen-vl": cfg},
default="qwen-vl",
)
session = _make_session(registry=registry, model_alias="qwen-vl")
# Ensure provider returns a real ModelCapabilities (not MagicMock)
session._provider.get_capabilities = MagicMock(return_value=ModelCapabilities())
caps = session._get_capabilities()
assert caps.supports_vision is True
def test_no_override_uses_provider_default(self, tmp_db):
"""Without config override, provider defaults are used."""
session = _make_session()
caps = session._get_capabilities()
# Default OpenAI provider for unknown model → no vision
assert caps.supports_vision is False