Port init elements code

Closes #2 (closed)

tests/conftest.py

 import os
+import sys
 
 import pytest
 
 from arkindex.mock import MockApiClient
 from arkindex_worker.worker.base import BaseWorker
+from worker_init_elements.worker import InitElementWorker
+
+
+@pytest.fixture()
+def mock_api_client() -> MockApiClient:
+    return MockApiClient()
 
 
 @pytest.fixture(autouse=True)
-def _setup_environment(responses, monkeypatch) -> None:
+def _setup_environment(mock_api_client: MockApiClient, responses, monkeypatch) -> None:
     """Setup needed environment variables"""
 
     # Allow accessing remote API schemas
@@ -27,6 +34,80 @@ def _setup_environment(responses, monkeypatch) -> None:
 
     # Setup a mock api client instead of using a real one
     def mock_setup_api_client(self):
-        self.api_client = MockApiClient()
+        self.api_client = mock_api_client
 
     monkeypatch.setattr(BaseWorker, "setup_api_client", mock_setup_api_client)
+
+
+@pytest.fixture()
+def _mock_worker_run_api(mock_api_client: MockApiClient) -> None:
+    """Provide a mock API response to get worker run information"""
+    mock_api_client.add_response(
+        "RetrieveWorkerRun",
+        id=os.getenv("ARKINDEX_WORKER_RUN_ID"),
+        response={
+            "id": os.getenv("ARKINDEX_WORKER_RUN_ID"),
+            "worker_version": {
+                "id": "12341234-1234-1234-1234-123412341234",
+                "revision": {"hash": "deadbeef1234"},
+                "worker": {"name": "Fake worker"},
+                "configuration": {
+                    "name": "Init Elements",
+                    "slug": "init-elements",
+                    "type": "extractor",
+                    "docker": {
+                        "build": "Dockerfile",
+                        "image": "",
+                        "command": None,
+                        "context": None,
+                        "shm_size": None,
+                        "environment": {},
+                    },
+                    "secrets": [],
+                    "description": None,
+                    "configuration": {},
+                    "user_configuration": {
+                        "chunks_number": {
+                            "type": "int",
+                            "title": "Chunks number",
+                            "default": 1,
+                            "required": True,
+                        },
+                        "use_cache": {
+                            "type": "bool",
+                            "title": "Use cache",
+                            "default": False,
+                        },
+                        "threshold_value": {
+                            "type": "float",
+                            "title": "Threshold Value",
+                            "default": 0.1,
+                            "subtype": "number",
+                            "required": False,
+                        },
+                        "sleep": {
+                            "type": "float",
+                            "title": "Sleep",
+                            "default": 0.0,
+                        },
+                    },
+                },
+            },
+            "configuration": None,
+            "process": {"id": "process_id", "corpus": os.getenv("ARKINDEX_CORPUS_ID")},
+            "summary": os.getenv("ARKINDEX_WORKER_RUN_ID") + " @ version 1",
+        },
+    )
+
+
+@pytest.fixture()
+def mock_worker(
+    _mock_worker_run_api, tmp_path_factory, monkeypatch
+) -> InitElementWorker:
+    monkeypatch.setattr(sys, "argv", ["worker-init-elements"])
+
+    worker = InitElementWorker()
+    worker.work_dir = tmp_path_factory.mktemp("data")
+    worker.configure()
+
+    return worker