starlette/tests/middleware/test_gzip.py

from starlette.applications import Starlette
from starlette.middleware.gzip import GZipMiddleware
from starlette.responses import PlainTextResponse, StreamingResponse


def test_gzip_responses(test_client_factory):
    app = Starlette()

    app.add_middleware(GZipMiddleware)

    @app.route("/")
    def homepage(request):
        return PlainTextResponse("x" * 4000, status_code=200)

    client = test_client_factory(app)
    response = client.get("/", headers={"accept-encoding": "gzip"})
    assert response.status_code == 200
    assert response.text == "x" * 4000
    assert response.headers["Content-Encoding"] == "gzip"
    assert int(response.headers["Content-Length"]) < 4000


def test_gzip_not_in_accept_encoding(test_client_factory):
    app = Starlette()

    app.add_middleware(GZipMiddleware)

    @app.route("/")
    def homepage(request):
        return PlainTextResponse("x" * 4000, status_code=200)

    client = test_client_factory(app)
    response = client.get("/", headers={"accept-encoding": "identity"})
    assert response.status_code == 200
    assert response.text == "x" * 4000
    assert "Content-Encoding" not in response.headers
    assert int(response.headers["Content-Length"]) == 4000


def test_gzip_ignored_for_small_responses(test_client_factory):
    app = Starlette()

    app.add_middleware(GZipMiddleware)

    @app.route("/")
    def homepage(request):
        return PlainTextResponse("OK", status_code=200)

    client = test_client_factory(app)
    response = client.get("/", headers={"accept-encoding": "gzip"})
    assert response.status_code == 200
    assert response.text == "OK"
    assert "Content-Encoding" not in response.headers
    assert int(response.headers["Content-Length"]) == 2


def test_gzip_streaming_response(test_client_factory):
    app = Starlette()

    app.add_middleware(GZipMiddleware)

    @app.route("/")
    def homepage(request):
        async def generator(bytes, count):
            for index in range(count):
                yield bytes

        streaming = generator(bytes=b"x" * 400, count=10)
        return StreamingResponse(streaming, status_code=200)

    client = test_client_factory(app)
    response = client.get("/", headers={"accept-encoding": "gzip"})
    assert response.status_code == 200
    assert response.text == "x" * 4000
    assert response.headers["Content-Encoding"] == "gzip"
    assert "Content-Length" not in response.headers