Writing a manual functional test

Introduction to FastAPI

Matt Eckerle

Software and Data Engineering Leader

What Are Functional Tests?

System Tests

Focus: Isolated system operations
Purpose: Validate system function
Scope: Endpoint
Environment: Python env with app running

def test_read():
    response = client.get("/items/1")
    assert response.status_code == 200

Functional Tests

Focus: Integrated system
Purpose: Validate system overall
Scope: Application
Environment: Python env with app running

def test_delete_then_read():
    response = client.delete("/items/1")
    assert response.status_code == 200
    response = client.get("/items/1")
    assert response.status_code == 404

Test Workflows

Diagrams showing examples of success and failure test workflows

Functional Test Workflow Examples

Successful workflows

Create, then read
Create, then update
Create, then delete
...

Failing workflows

Read without create
Update after delete
Delete without create
...

Functional Test Scripts

Outside test framework - "Manual tests"
Use requests

import requests
ENDPOINT = "http://localhost:8000/items"
# Create item "rock"
r = requests.post(ENDPOINT, json={"name": "rock"})
assert r.status_code == 200
# Get item rock
r = requests.get(ENDPOINT, json={"name": "rock"})
assert r.status_code == 200

Workflows built against known application state

Let's practice!

Introduction to FastAPI

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