refactor: move tests folder structure and update pytest commands (#2785)

* refactor: move tests folder to src/backend

* chore(Makefile): update pytest commands to run tests from the correct directory paths for unit and integration tests

* refactor: update file path in test_custom_component.py

The file path in the test_custom_component.py file has been updated to use the correct relative path to the component_multiple_outputs.py file. This change ensures that the test code can access the correct file and improves the reliability of the test.

src/backend/tests/integration/langflow.py

@@ -0,0 +1,88 @@
+from uuid import uuid4
+
+import pytest
+from fastapi import status
+from fastapi.testclient import TestClient
+
+from langflow.graph.schema import RunOutputs
+from langflow.initial_setup.setup import load_starter_projects
+from langflow.load import run_flow_from_json
+
+
+@pytest.mark.api_key_required
+def test_run_flow_with_caching_success(client: TestClient, starter_project, created_api_key):
+    flow_id = starter_project["id"]
+    headers = {"x-api-key": created_api_key.api_key}
+    payload = {
+        "input_value": "value1",
+        "input_type": "text",
+        "output_type": "text",
+        "tweaks": {"parameter_name": "value"},
+        "stream": False,
+    }
+    response = client.post(f"/api/v1/run/{flow_id}", json=payload, headers=headers)
+    assert response.status_code == status.HTTP_200_OK
+    data = response.json()
+    assert "outputs" in data
+    assert "session_id" in data
+
+
+@pytest.mark.api_key_required
+def test_run_flow_with_caching_invalid_flow_id(client: TestClient, created_api_key):
+    invalid_flow_id = uuid4()
+    headers = {"x-api-key": created_api_key.api_key}
+    payload = {"input_value": "", "input_type": "text", "output_type": "text", "tweaks": {}, "stream": False}
+    response = client.post(f"/api/v1/run/{invalid_flow_id}", json=payload, headers=headers)
+    assert response.status_code == status.HTTP_404_NOT_FOUND
+    data = response.json()
+    assert "detail" in data
+    assert f"Flow identifier {invalid_flow_id} not found" in data["detail"]
+
+
+@pytest.mark.api_key_required
+def test_run_flow_with_caching_invalid_input_format(client: TestClient, starter_project, created_api_key):
+    flow_id = starter_project["id"]
+    headers = {"x-api-key": created_api_key.api_key}
+    payload = {"input_value": {"key": "value"}, "input_type": "text", "output_type": "text", "tweaks": {}}
+    response = client.post(f"/api/v1/run/{flow_id}", json=payload, headers=headers)
+    assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+
+
+@pytest.mark.api_key_required
+def test_run_flow_with_invalid_tweaks(client, starter_project, created_api_key):
+    headers = {"x-api-key": created_api_key.api_key}
+    flow_id = starter_project["id"]
+    payload = {
+        "input_value": "value1",
+        "input_type": "text",
+        "output_type": "text",
+        "tweaks": {"invalid_tweak": "value"},
+    }
+    response = client.post(f"/api/v1/run/{flow_id}", json=payload, headers=headers)
+    assert response.status_code == status.HTTP_200_OK
+
+
+@pytest.mark.api_key_required
+def test_run_with_inputs_and_outputs(client, starter_project, created_api_key):
+    headers = {"x-api-key": created_api_key.api_key}
+    flow_id = starter_project["id"]
+    payload = {
+        "input_value": "value1",
+        "input_type": "text",
+        "output_type": "text",
+        "tweaks": {"parameter_name": "value"},
+        "stream": False,
+    }
+    response = client.post(f"/api/v1/run/{flow_id}", json=payload, headers=headers)
+    assert response.status_code == status.HTTP_200_OK, response.text
+
+
+@pytest.mark.noclient
+@pytest.mark.api_key_required
+def test_run_flow_from_json_object():
+    """Test loading a flow from a json file and applying tweaks"""
+    _, projects = zip(*load_starter_projects())
+    project = [project for project in projects if "Basic Prompting" in project["name"]][0]
+    results = run_flow_from_json(project, input_value="test", fallback_to_env_vars=True)
+    assert results is not None
+    assert all(isinstance(result, RunOutputs) for result in results)