---
title: Testing
menu: docs_advanced
weight: 210
---

# Testing

Every application should be well tested. Actix provides tools to perform unit and
integration tests.

# Unit Tests

For unit testing, actix provides a request builder type and a simple handler runner.
[*TestRequest*](../../actix-web/actix_web/test/struct.TestRequest.html)
implements a builder-like pattern.
You can generate a `HttpRequest` instance with `finish()`, or you can
run your handler with `run()` or `run_async()`.

```rust
use actix_web::{http, test, HttpRequest, HttpResponse, HttpMessage};

fn index(req: &HttpRequest) -> HttpResponse {
     if let Some(hdr) = req.headers().get(http::header::CONTENT_TYPE) {
        if let Ok(s) = hdr.to_str() {
            return HttpResponse::Ok().into()
        }
     }
     HttpResponse::BadRequest().into()
}

fn main() {
    let resp = test::TestRequest::with_header("content-type", "text/plain")
        .run(&index)
        .unwrap();
    assert_eq!(resp.status(), http::StatusCode::OK);

    let resp = test::TestRequest::default()
        .run(&index)
        .unwrap();
    assert_eq!(resp.status(), http::StatusCode::BAD_REQUEST);
}
```

# Integration tests

There are several methods for testing your application. Actix provides
[*TestServer*](../../actix-web/actix_web/test/struct.TestServer.html), which can be used
to run the application with specific handlers in a real http server.

`TestServer::get()`, `TestServer::post()`, and `TestServer::client()`
methods can be used to send requests to the test server.

A simple form `TestServer` can be configured to use a handler.
`TestServer::new` method accepts a configuration function, and the only argument 
for this function is a *test application* instance.

> Check the [api documentation](../../actix-web/actix_web/test/struct.TestApp.html)
> for more information.

```rust
use actix_web::{HttpRequest, HttpMessage};
use actix_web::test::TestServer;
use std::str;

fn index(req: HttpRequest) -> &'static str {
     "Hello world!"
}

fn main() {
    // start new test server
    let mut srv = TestServer::new(|app| app.handler(index));

    let request = srv.get().finish().unwrap();
    let response = srv.execute(request.send()).unwrap();
    assert!(response.status().is_success());

    let bytes = srv.execute(response.body()).unwrap();
    let body = str::from_utf8(&bytes).unwrap();
    assert_eq!(body, "Hello world!");
}
```

The other option is to use an application factory. In this case, you need to pass the factory
function the same way as you would for real http server configuration.

```rust
use actix_web::{http, test, App, HttpRequest, HttpResponse};

fn index(req: &HttpRequest) -> HttpResponse {
     HttpResponse::Ok().into()
}

/// This function get called by http server.
fn create_app() -> App {
    App::new()
        .resource("/test", |r| r.h(index))
}

fn main() {
    let mut srv = test::TestServer::with_factory(create_app);

    let request = srv.client(
         http::Method::GET, "/test").finish().unwrap();
    let response = srv.execute(request.send()).unwrap();

    assert!(response.status().is_success());
}
```

If you need more complex application configuration, use the `TestServer::build_with_state()`
method. For example, you may need to initialize application state or start `SyncActor`'s for diesel
interation. This method accepts a closure that constructs the application state,
and it runs when the actix system is configured. Thus, you can initialize any additional actors.

```rust
#[test]
fn test() {
    let srv = TestServer::build_with_state(|| {
        // we can start diesel actors
        let addr = SyncArbiter::start(3, || {
            DbExecutor(SqliteConnection::establish("test.db").unwrap())
        });
        // then we can construct custom state, or it could be `()`
        MyState{addr: addr}
   })

   // register server handlers and start test server
   .start(|app| {
        app.resource(
            "/{username}/index.html", |r| r.with(
                |p: Path<PParam>| format!("Welcome {}!", p.username)));
    });
    
    // now we can run our test code
);
```


# Stream response tests

If you need to test stream it would be enough to convert a [*ClientResponse*](../../actix-web/actix_web/client/struct.ClientResponse.html) to future and execute it.
For example of testing [*Server Sent Events*](https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events).

```rust
extern crate bytes;
extern crate futures;
extern crate actix_web;

use bytes::Bytes;
use futures::stream::poll_fn;
use futures::{Async, Poll, Stream};

use actix_web::{HttpRequest, HttpResponse, Error};
use actix_web::http::{ContentEncoding, StatusCode};
use actix_web::test::TestServer;


fn sse(_req: HttpRequest) -> HttpResponse {
    let mut counter = 5usize;
    // yields `data: N` where N in [5; 1]
    let server_events = poll_fn(move || -> Poll<Option<Bytes>, Error> {
        if counter == 0 {
            return Ok(Async::NotReady);
        }
        let payload = format!("data: {}\n\n", counter);
        counter -= 1;
        Ok(Async::Ready(Some(Bytes::from(payload))))
    });

    HttpResponse::build(StatusCode::OK)
        .content_encoding(ContentEncoding::Identity)
        .content_type("text/event-stream")
        .streaming(server_events)
}


fn main() {
    // start new test server
    let mut srv = TestServer::new(|app| app.handler(sse));

    // request stream
    let request = srv.get().finish().unwrap();
    let response = srv.execute(request.send()).unwrap();
    assert!(response.status().is_success());

    // convert ClientResponse to future, start read body and wait first chunk
    let (bytes, response) = srv.execute(response.into_future()).unwrap();
    assert_eq!(bytes.unwrap(), Bytes::from("data: 5\n\n"));

    // next chunk
    let (bytes, _) = srv.execute(response.into_future()).unwrap();
    assert_eq!(bytes.unwrap(), Bytes::from("data: 4\n\n"));
}
```

# WebSocket server tests

It is possible to register a *handler* with `TestApp::handler()`, which
initiates a web socket connection. *TestServer* provides the method `ws()`, which connects to
the websocket server and returns ws reader and writer objects. *TestServer* also
provides an `execute()` method, which runs future objects to completion and returns
result of the future computation.

The following example demonstrates how to test a websocket handler:

```rust
use actix_web::*;
use futures::Stream;

struct Ws;   // <- WebSocket actor

impl Actor for Ws {
    type Context = ws::WebsocketContext<Self>;
}

impl StreamHandler<ws::Message, ws::ProtocolError> for Ws {
    fn handle(&mut self, msg: ws::Message, ctx: &mut Self::Context) {
        match msg {
            ws::Message::Text(text) => ctx.text(text),
            _ => (),
        }
    }
}

fn main() {
    let mut srv = test::TestServer::new(
        |app| app.handler(|req| ws::start(req, Ws)));

    let (reader, mut writer) = srv.ws().unwrap();
    writer.text("text");

    let (item, reader) = srv.execute(reader.into_future()).unwrap();
    assert_eq!(item, Some(ws::Message::Text("text".to_owned())));
}
```