tests/test_api.py

import pytest
from fastapi.testclient import TestClient
from src.models.api import app, COMMODITY_MAP
import src.models.api as api
from unittest.mock import MagicMock

client = TestClient(app)

@pytest.fixture(autouse=True)
def mock_model():
    # Mock the global model variable in src.models.api
    api.model = MagicMock()
    yield
    api.model = None

def test_health_check():
    response = client.get("/")
    assert response.status_code == 200
    assert response.json()["service"] == "MLOps Forecasting API"

def test_predict_invalid_commodity():
    payload = {
        "commodity": "Invalid",
        "lag_prices": [200.0] * 7
    }
    response = client.post("/predict", json=payload)
    assert response.status_code == 400
    assert "Unknown commodity" in response.json()["detail"]

def test_predict_wrong_lag_count():
    payload = {
        "commodity": "Samba",
        "lag_prices": [200.0] * 5  # Should be 7
    }
    response = client.post("/predict", json=payload)
    assert response.status_code == 400
    assert "Exactly 7 lag prices" in response.json()["detail"]

def test_predict_success():
    api.model.predict.return_value = [250.0]
    payload = {
        "commodity": "Samba",
        "lag_prices": [200.0] * 7
    }
    response = client.post("/predict", json=payload)
    assert response.status_code == 200
    assert response.json()["predicted_price_lkr"] == 250.0