# macOS
brew tap azure/functions
brew install azure-functions-core-tools@4

# Ubuntu/Debian (see full APT steps at learn.microsoft.com/azure/azure-functions/functions-run-local#install-the-azure-functions-core-tools)
sudo apt-get install azure-functions-core-tools-4

# Windows: download the MSI from
# https://go.microsoft.com/fwlink/?linkid=2174087 (64-bit) per the Core Tools docs

func --version   # must be 4.x

npm install -g azurite

# .NET isolated worker model (recommended; in-process support ends 2026-11-10
# per learn.microsoft.com/azure/azure-functions/dotnet-isolated-in-process-differences)
func init MyApp --worker-runtime dotnet-isolated

# Node.js (v4 programming model)
func init MyApp --worker-runtime javascript --model V4

# Python (v2 programming model)
func init MyApp --worker-runtime python --model V2

# Add a trigger template
func new --template "Http Trigger" --name HttpExample
func new --template "Azure Queue Storage Trigger" --name QueueExample
func new --template "Timer trigger" --name TimerExample

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true"
  }
}

azurite --silent --location ./azurite-data

docker run -p 10000:10000 -p 10001:10001 -p 10002:10002 \
    mcr.microsoft.com/azure-storage/azurite

func start

Http Function HttpExample: http://localhost:7071/api/HttpExample

# GET
curl http://localhost:7071/api/HttpExample?name=World

# POST
curl --request POST http://localhost:7071/api/HttpExample \
     --data '{"name":"World"}'

# Queue trigger named QueueExample
curl --request POST \
     -H "Content-Type: application/json" \
     --data '{"input":"sample queue payload"}' \
     http://localhost:7071/admin/functions/QueueExample

# Timer trigger named TimerExample (empty input is valid)
curl --request POST \
     -H "Content-Type: application/json" \
     --data '{}' \
     http://localhost:7071/admin/functions/TimerExample

jobs:
  azure-functions-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Install Core Tools
        run: |
          curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.gpg
          sudo mv microsoft.gpg /etc/apt/trusted.gpg.d/microsoft.gpg
          sudo sh -c 'echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-ubuntu-$(lsb_release -cs)-prod $(lsb_release -cs) main" > /etc/apt/sources.list.d/dotnetdev.list'
          sudo apt-get update && sudo apt-get install -y azure-functions-core-tools-4
      - name: Start Azurite
        run: npx azurite --silent &
      - name: Run unit tests
        run: dotnet test   # or: pytest / npm test

// Handler under test
public class HttpExample
{
    [Function("HttpExample")]
    public HttpResponseData Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post")] HttpRequestData req,
        FunctionContext context)
    {
        var response = req.CreateResponse(HttpStatusCode.OK);
        response.WriteString("Hello from Azure Functions");
        return response;
    }
}

// xUnit test - construct HttpRequestData via a mock FunctionContext
// (use Moq, NSubstitute, or similar for FunctionContext and HttpRequestData)
[Fact]
public async Task Run_ReturnsOk()
{
    var context = new Mock<FunctionContext>();
    var request = CreateMockHttpRequest(context.Object, HttpMethod.Get);

    var function = new HttpExample();
    var response = function.Run(request, context.Object);

    Assert.Equal(HttpStatusCode.OK, response.StatusCode);
}

// handler.js
const { app } = require('@azure/functions');

app.http('HttpExample', {
  methods: ['GET', 'POST'],
  authLevel: 'anonymous',
  handler: async (request, context) => {
    const name = request.query.get('name') || 'World';
    return { body: `Hello, ${name}!` };
  },
});

// handler.test.js (Jest)
const { handler } = require('./handler');

test('returns greeting', async () => {
  const req = { query: new URLSearchParams('name=Test'), text: async () => '' };
  const ctx = { log: jest.fn() };
  const res = await handler(req, ctx);
  expect(res.body).toBe('Hello, Test!');
});

# function_app.py
import azure.functions as func
app = func.FunctionApp()

@app.route(route="HttpExample")
def http_example(req: func.HttpRequest) -> func.HttpResponse:
    name = req.params.get('name', 'World')
    return func.HttpResponse(f"Hello, {name}!")

# test_function_app.py (pytest)
import azure.functions as func
from function_app import http_example

def test_http_example():
    req = func.HttpRequest(
        method='GET',
        url='/api/HttpExample',
        params={'name': 'Test'},
        body=b''
    )
    resp = http_example(req)
    assert resp.status_code == 200
    assert 'Test' in resp.get_body().decode()