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pytest conftest Fixture Dependency Graph & mock.patch Leak Detector

Statically analyze a pytest conftest.py chain: render the fixture dependency graph across all five scopes (function/class/module/package/session), detect deeper-conftest overrides, ScopeMismatch edges, and cross-test state pollution — mock.patch().start() without .stop(), monkeypatch leaking from broad-scope fixtures, and with mock.patch held open across yield.

html· HTML resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

# 1) Request a presigned URL → returns { uploadUrl, storageKey }
curl -X POST 'http://127.0.0.1:3003/api/upload/presign/pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector' \
  -H 'Content-Type: application/json' \
  -d '{"filename":"pythonFile.ext","contentType":"application/octet-stream","size":12345}'

# 2) PUT the file bytes directly to the presigned uploadUrl
curl -X PUT '<presigned uploadUrl>' \
  --data-binary @/path/to/file.ext

# 3) Call the tool, passing the returned storageKey for each file field
curl -X POST 'http://127.0.0.1:3003/en/api/tools/pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector' \
  -F 'sourceInput=# --- file: conftest.py ---
import pytest
from unittest import mock

@pytest.fixture(scope="session")
def db_engine():
    engine = {"url": "sqlite://"}
    yield engine
    engine.clear()

@pytest.fixture(scope="session")
def patched_auth():
    patcher = mock.patch("auth.verify_token", return_value=True)
    patcher.start()
    return None

@pytest.fixture
def api_client(db_engine, patched_auth):
    return {"db": db_engine}

# --- file: tests/unit/conftest.py ---
import pytest

@pytest.fixture(scope="module")
def fake_auth(monkeypatch):
    monkeypatch.setattr("auth.verify_token", lambda t: True)
    return True

@pytest.fixture
def api_client(fake_auth):
    return {"override": True}' \
  -F 'pythonFile=uploads/2026/01/01/your-tool-1700000000000-abc123.ext' \
  -F 'includeBuiltinGraph=true'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST http://127.0.0.1:3003/en/api/tools/pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector

Parameters

Name	Type	Required	Description
sourceInput	textarea	Yes	—
pythonFile	fileupload required	No	—
includeBuiltinGraph	checkbox	No	—

File-type parameters must be uploaded first via POST /upload/pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector, then the returned filePath is passed to the corresponding file field.

Response format

HTML result

JSON

{
  "result": "<div>Processed HTML content</div>",
  "error": "Error message (optional)",
  "message": "Notification message (optional)",
  "metadata": {
    "key": "value"
  }
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector": {
      "name": "pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector",
      "description": "Statically analyze a pytest conftest.py chain: render the fixture dependency graph across all five scopes (function/class/module/package/session), detect deeper-conftest overrides, ScopeMismatch edges, and cross-test state pollution — mock.patch().start() without .stop(), monkeypatch leaking from broad-scope fixtures, and with mock.patch held open across yield.",
      "baseUrl": "http://127.0.0.1:3003/mcp/sse?toolId=pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "pytest-conftest-fixture-dependency-graph-and-mock-patch-leak-detector",
    "arguments": {
  "sourceInput": "# --- file: conftest.py ---\nimport pytest\nfrom unittest import mock\n\[email protected](scope=\"session\")\ndef db_engine():\n    engine = {\"url\": \"sqlite://\"}\n    yield engine\n    engine.clear()\n\[email protected](scope=\"session\")\ndef patched_auth():\n    patcher = mock.patch(\"auth.verify_token\", return_value=True)\n    patcher.start()\n    return None\n\[email protected]\ndef api_client(db_engine, patched_auth):\n    return {\"db\": db_engine}\n\n# --- file: tests/unit/conftest.py ---\nimport pytest\n\[email protected](scope=\"module\")\ndef fake_auth(monkeypatch):\n    monkeypatch.setattr(\"auth.verify_token\", lambda t: True)\n    return True\n\[email protected]\ndef api_client(fake_auth):\n    return {\"override\": True}",
  "pythonFile": "https://example.com/file.ext",
  "includeBuiltinGraph": true
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

File parameters accept a public file URL only (https://…). Local paths, data: URIs, and Base64 strings are not supported.

Questions or issues? Contact [email protected]