githubmirror/flask

tests/test_basic.py
1 890 строк51 KB
David Lord
use ruff linter and formatter
15 ноя 2023, 23:14
15 ноя 2023, 23:1454e05a2
import gc
import re
import uuid
import warnings
import weakref
from datetime import datetime
from datetime import timezone
from platform import python_implementation

import pytest
import werkzeug.serving
from markupsafe import Markup
from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import Forbidden
from werkzeug.exceptions import NotFound
from werkzeug.http import parse_date
from werkzeug.routing import BuildError
from werkzeug.routing import RequestRedirect

import flask

require_cpython_gc = pytest.mark.skipif(
    python_implementation() != "CPython",
    reason="Requires CPython GC behavior",
)


def test_options_work(app, client):
    @app.route("/", methods=["GET", "POST"])
    def index():
        return "Hello World"

    rv = client.open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]
    assert rv.data == b""


def test_options_on_multiple_rules(app, client):
    @app.route("/", methods=["GET", "POST"])
    def index():
        return "Hello World"

    @app.route("/", methods=["PUT"])
    def index_put():
        return "Aha!"

    rv = client.open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST", "PUT"]


@pytest.mark.parametrize("method", ["get", "post", "put", "delete", "patch"])
def test_method_route(app, client, method):
    method_route = getattr(app, method)
    client_method = getattr(client, method)

    @method_route("/")
    def hello():
        return "Hello"

    assert client_method("/").data == b"Hello"


def test_method_route_no_methods(app):
    with pytest.raises(TypeError):
        app.get("/", methods=["GET", "POST"])


def test_provide_automatic_options_attr():
    app = flask.Flask(__name__)

    def index():
        return "Hello World!"

    index.provide_automatic_options = False
    app.route("/")(index)
    rv = app.test_client().open("/", method="OPTIONS")
    assert rv.status_code == 405

    app = flask.Flask(__name__)

    def index2():
        return "Hello World!"

    index2.provide_automatic_options = True
    app.route("/", methods=["OPTIONS"])(index2)
    rv = app.test_client().open("/", method="OPTIONS")
    assert sorted(rv.allow) == ["OPTIONS"]


def test_provide_automatic_options_kwarg(app, client):
    def index():
        return flask.request.method

    def more():
        return flask.request.method

    app.add_url_rule("/", view_func=index, provide_automatic_options=False)
    app.add_url_rule(
        "/more",
        view_func=more,
        methods=["GET", "POST"],
        provide_automatic_options=False,
    )
    assert client.get("/").data == b"GET"

    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD"]

    rv = client.open("/", method="OPTIONS")
    assert rv.status_code == 405

    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"

    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "POST"]

    rv = client.open("/more", method="OPTIONS")
    assert rv.status_code == 405


def test_request_dispatching(app, client):
    @app.route("/")
    def index():
        return flask.request.method

    @app.route("/more", methods=["GET", "POST"])
    def more():
        return flask.request.method

    assert client.get("/").data == b"GET"
    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS"]
    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"
    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]


def test_disallow_string_for_allowed_methods(app):
    with pytest.raises(TypeError):
        app.add_url_rule("/", methods="GET POST", endpoint="test")


def test_url_mapping(app, client):
    random_uuid4 = "7eb41166-9ebf-4d26-b771-ea3f54f8b383"

    def index():
        return flask.request.method

    def more():
        return flask.request.method

    def options():
        return random_uuid4

    app.add_url_rule("/", "index", index)
    app.add_url_rule("/more", "more", more, methods=["GET", "POST"])

    # Issue 1288: Test that automatic options are not added
    #             when non-uppercase 'options' in methods
    app.add_url_rule("/options", "options", options, methods=["options"])

    assert client.get("/").data == b"GET"
    rv = client.post("/")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS"]
    rv = client.head("/")
    assert rv.status_code == 200
    assert not rv.data  # head truncates
    assert client.post("/more").data == b"POST"
    assert client.get("/more").data == b"GET"
    rv = client.delete("/more")
    assert rv.status_code == 405
    assert sorted(rv.allow) == ["GET", "HEAD", "OPTIONS", "POST"]
    rv = client.open("/options", method="OPTIONS")
    assert rv.status_code == 200
    assert random_uuid4 in rv.data.decode("utf-8")


def test_werkzeug_routing(app, client):
    from werkzeug.routing import Rule
    from werkzeug.routing import Submount

    app.url_map.add(
        Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
    )

    def bar():
        return "bar"

    def index():
        return "index"

    app.view_functions["bar"] = bar
    app.view_functions["index"] = index

    assert client.get("/foo/").data == b"index"
    assert client.get("/foo/bar").data == b"bar"


def test_endpoint_decorator(app, client):
    from werkzeug.routing import Rule
    from werkzeug.routing import Submount

    app.url_map.add(
        Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
    )

    @app.endpoint("bar")
    def bar():
        return "bar"

    @app.endpoint("index")
    def index():
        return "index"

    assert client.get("/foo/").data == b"index"
    assert client.get("/foo/bar").data == b"bar"


def test_session(app, client):
    @app.route("/set", methods=["POST"])
    def set():
        assert not flask.session.accessed
        assert not flask.session.modified
        flask.session["value"] = flask.request.form["value"]
        assert flask.session.accessed
        assert flask.session.modified
        return "value set"

    @app.route("/get")
    def get():
        assert not flask.session.accessed
        assert not flask.session.modified
        v = flask.session.get("value", "None")
        assert flask.session.accessed
        assert not flask.session.modified
        return v

    assert client.post("/set", data={"value": "42"}).data == b"value set"
    assert client.get("/get").data == b"42"


def test_session_path(app, client):
    app.config.update(APPLICATION_ROOT="/foo")

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    rv = client.get("/", "http://example.com:8080/foo")
    assert "path=/foo" in rv.headers["set-cookie"].lower()


def test_session_using_application_root(app, client):
    class PrefixPathMiddleware:
        def __init__(self, app, prefix):
            self.app = app
            self.prefix = prefix

        def __call__(self, environ, start_response):
            environ["SCRIPT_NAME"] = self.prefix
            return self.app(environ, start_response)

    app.wsgi_app = PrefixPathMiddleware(app.wsgi_app, "/bar")
    app.config.update(APPLICATION_ROOT="/bar")

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    rv = client.get("/", "http://example.com:8080/")
    assert "path=/bar" in rv.headers["set-cookie"].lower()


def test_session_using_session_settings(app, client):
    app.config.update(
        SERVER_NAME="www.example.com:8080",
        APPLICATION_ROOT="/test",
        SESSION_COOKIE_DOMAIN=".example.com",
        SESSION_COOKIE_HTTPONLY=False,
        SESSION_COOKIE_SECURE=True,
        SESSION_COOKIE_SAMESITE="Lax",
        SESSION_COOKIE_PATH="/",
    )

    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    @app.route("/clear")
    def clear():
        flask.session.pop("testing", None)
        return "Goodbye World"

    rv = client.get("/", "http://www.example.com:8080/test/")
    cookie = rv.headers["set-cookie"].lower()
    # or condition for Werkzeug < 2.3
    assert "domain=example.com" in cookie or "domain=.example.com" in cookie
    assert "path=/" in cookie
    assert "secure" in cookie
    assert "httponly" not in cookie
    assert "samesite" in cookie

    rv = client.get("/clear", "http://www.example.com:8080/test/")
    cookie = rv.headers["set-cookie"].lower()
    assert "session=;" in cookie
    # or condition for Werkzeug < 2.3
    assert "domain=example.com" in cookie or "domain=.example.com" in cookie
    assert "path=/" in cookie
    assert "secure" in cookie
    assert "samesite" in cookie


def test_session_using_samesite_attribute(app, client):
    @app.route("/")
    def index():
        flask.session["testing"] = 42
        return "Hello World"

    app.config.update(SESSION_COOKIE_SAMESITE="invalid")

    with pytest.raises(ValueError):
        client.get("/")

    app.config.update(SESSION_COOKIE_SAMESITE=None)
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite" not in cookie

    app.config.update(SESSION_COOKIE_SAMESITE="Strict")
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite=strict" in cookie

    app.config.update(SESSION_COOKIE_SAMESITE="Lax")
    rv = client.get("/")
    cookie = rv.headers["set-cookie"].lower()
    assert "samesite=lax" in cookie


def test_missing_session(app):
    app.secret_key = None

    def expect_exception(f, *args, **kwargs):
        e = pytest.raises(RuntimeError, f, *args, **kwargs)
        assert e.value.args and "session is unavailable" in e.value.args[0]

    with app.test_request_context():
        assert flask.session.get("missing_key") is None
        expect_exception(flask.session.__setitem__, "foo", 42)
        expect_exception(flask.session.pop, "foo")


def test_session_expiration(app, client):
    permanent = True

    @app.route("/")
    def index():
        flask.session["test"] = 42
        flask.session.permanent = permanent
        return ""

    @app.route("/test")
    def test():
        return str(flask.session.permanent)

    rv = client.get("/")
    assert "set-cookie" in rv.headers
    match = re.search(r"(?i)\bexpires=([^;]+)", rv.headers["set-cookie"])
    expires = parse_date(match.group())
    expected = datetime.now(timezone.utc) + app.permanent_session_lifetime
    assert expires.year == expected.year
    assert expires.month == expected.month
    assert expires.day == expected.day

    rv = client.get("/test")
    assert rv.data == b"True"

    permanent = False
    rv = client.get("/")
    assert "set-cookie" in rv.headers
    match = re.search(r"\bexpires=([^;]+)", rv.headers["set-cookie"])
    assert match is None


def test_session_stored_last(app, client):
    @app.after_request
    def modify_session(response):
        flask.session["foo"] = 42
        return response

    @app.route("/")
    def dump_session_contents():
        return repr(flask.session.get("foo"))

    assert client.get("/").data == b"None"
    assert client.get("/").data == b"42"


def test_session_special_types(app, client):
    now = datetime.now(timezone.utc).replace(microsecond=0)
    the_uuid = uuid.uuid4()

    @app.route("/")
    def dump_session_contents():
        flask.session["t"] = (1, 2, 3)
        flask.session["b"] = b"\xff"
        flask.session["m"] = Markup("<html>")
        flask.session["u"] = the_uuid
        flask.session["d"] = now
        flask.session["t_tag"] = {" t": "not-a-tuple"}
        flask.session["di_t_tag"] = {" t__": "not-a-tuple"}
        flask.session["di_tag"] = {" di": "not-a-dict"}
        return "", 204

    with client:
        client.get("/")
        s = flask.session
        assert s["t"] == (1, 2, 3)
        assert type(s["b"]) is bytes  # noqa: E721
        assert s["b"] == b"\xff"
        assert type(s["m"]) is Markup  # noqa: E721
        assert s["m"] == Markup("<html>")
        assert s["u"] == the_uuid
        assert s["d"] == now
        assert s["t_tag"] == {" t": "not-a-tuple"}
        assert s["di_t_tag"] == {" t__": "not-a-tuple"}
        assert s["di_tag"] == {" di": "not-a-dict"}


def test_session_cookie_setting(app):
    is_permanent = True

    @app.route("/bump")
    def bump():
        rv = flask.session["foo"] = flask.session.get("foo", 0) + 1
        flask.session.permanent = is_permanent
        return str(rv)

    @app.route("/read")
    def read():
        return str(flask.session.get("foo", 0))

    def run_test(expect_header):
        with app.test_client() as c:
            assert c.get("/bump").data == b"1"
            assert c.get("/bump").data == b"2"
            assert c.get("/bump").data == b"3"

            rv = c.get("/read")
            set_cookie = rv.headers.get("set-cookie")
            assert (set_cookie is not None) == expect_header
            assert rv.data == b"3"

    is_permanent = True
    app.config["SESSION_REFRESH_EACH_REQUEST"] = True
    run_test(expect_header=True)

    is_permanent = True
    app.config["SESSION_REFRESH_EACH_REQUEST"] = False
    run_test(expect_header=False)

    is_permanent = False
    app.config["SESSION_REFRESH_EACH_REQUEST"] = True
    run_test(expect_header=False)

    is_permanent = False
    app.config["SESSION_REFRESH_EACH_REQUEST"] = False
    run_test(expect_header=False)


def test_session_vary_cookie(app, client):
    @app.route("/set")
    def set_session():
        flask.session["test"] = "test"
        return ""

    @app.route("/get")
    def get():
        return flask.session.get("test")

    @app.route("/getitem")
    def getitem():
        return flask.session["test"]

    @app.route("/setdefault")
    def setdefault():
        return flask.session.setdefault("test", "default")

    @app.route("/clear")
    def clear():
        flask.session.clear()
        return ""

    @app.route("/vary-cookie-header-set")
    def vary_cookie_header_set():
        response = flask.Response()
        response.vary.add("Cookie")
        flask.session["test"] = "test"
        return response

    @app.route("/vary-header-set")
    def vary_header_set():
        response = flask.Response()
        response.vary.update(("Accept-Encoding", "Accept-Language"))
        flask.session["test"] = "test"
        return response

    @app.route("/no-vary-header")
    def no_vary_header():
        return ""

    def expect(path, header_value="Cookie"):
        rv = client.get(path)

        if header_value:
            # The 'Vary' key should exist in the headers only once.
            assert len(rv.headers.get_all("Vary")) == 1
            assert rv.headers["Vary"] == header_value
        else:
            assert "Vary" not in rv.headers

    expect("/set")
    expect("/get")
    expect("/getitem")
    expect("/setdefault")
    expect("/clear")
    expect("/vary-cookie-header-set")
    expect("/vary-header-set", "Accept-Encoding, Accept-Language, Cookie")
    expect("/no-vary-header", None)


def test_session_refresh_vary(app, client):
    @app.get("/login")
    def login():
        flask.session["user_id"] = 1
        flask.session.permanent = True
        return ""

    @app.get("/ignored")
    def ignored():
        return ""

    rv = client.get("/login")
    assert rv.headers["Vary"] == "Cookie"
    rv = client.get("/ignored")
    assert rv.headers["Vary"] == "Cookie"


def test_flashes(app, req_ctx):
    assert not flask.session.modified
    flask.flash("Zap")
    flask.session.modified = False
    flask.flash("Zip")
    assert flask.session.modified
    assert list(flask.get_flashed_messages()) == ["Zap", "Zip"]


def test_extended_flashing(app):
    # Be sure app.testing=True below, else tests can fail silently.
    #
    # Specifically, if app.testing is not set to True, the AssertionErrors
    # in the view functions will cause a 500 response to the test client
    # instead of propagating exceptions.

    @app.route("/")
    def index():
        flask.flash("Hello World")
        flask.flash("Hello World", "error")
        flask.flash(Markup("<em>Testing</em>"), "warning")
        return ""

    @app.route("/test/")
    def test():
        messages = flask.get_flashed_messages()
        assert list(messages) == [
            "Hello World",
            "Hello World",
            Markup("<em>Testing</em>"),
        ]
        return ""

    @app.route("/test_with_categories/")
    def test_with_categories():
        messages = flask.get_flashed_messages(with_categories=True)
        assert len(messages) == 3
        assert list(messages) == [
            ("message", "Hello World"),
            ("error", "Hello World"),
            ("warning", Markup("<em>Testing</em>")),
        ]
        return ""

    @app.route("/test_filter/")
    def test_filter():
        messages = flask.get_flashed_messages(
            category_filter=["message"], with_categories=True
        )
        assert list(messages) == [("message", "Hello World")]
        return ""

    @app.route("/test_filters/")
    def test_filters():
        messages = flask.get_flashed_messages(
            category_filter=["message", "warning"], with_categories=True
        )
        assert list(messages) == [
            ("message", "Hello World"),
            ("warning", Markup("<em>Testing</em>")),
        ]
        return ""

    @app.route("/test_filters_without_returning_categories/")
    def test_filters2():
        messages = flask.get_flashed_messages(category_filter=["message", "warning"])
        assert len(messages) == 2
        assert messages[0] == "Hello World"
        assert messages[1] == Markup("<em>Testing</em>")
        return ""

    # Create new test client on each test to clean flashed messages.

    client = app.test_client()
    client.get("/")
    client.get("/test_with_categories/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filter/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filters/")

    client = app.test_client()
    client.get("/")
    client.get("/test_filters_without_returning_categories/")


def test_request_processing(app, client):
    evts = []

    @app.before_request
    def before_request():
        evts.append("before")

    @app.after_request
    def after_request(response):
        response.data += b"|after"
        evts.append("after")
        return response

    @app.route("/")
    def index():
        assert "before" in evts
        assert "after" not in evts
        return "request"

    assert "after" not in evts
    rv = client.get("/").data
    assert "after" in evts
    assert rv == b"request|after"


def test_request_preprocessing_early_return(app, client):
    evts = []

    @app.before_request
    def before_request1():
        evts.append(1)

    @app.before_request
    def before_request2():
        evts.append(2)
        return "hello"

    @app.before_request
    def before_request3():
        evts.append(3)
        return "bye"

    @app.route("/")
    def index():
        evts.append("index")
        return "damnit"

    rv = client.get("/").data.strip()
    assert rv == b"hello"
    assert evts == [1, 2]


def test_after_request_processing(app, client):
    @app.route("/")
    def index():
        @flask.after_this_request
        def foo(response):
            response.headers["X-Foo"] = "a header"
            return response

        return "Test"

    resp = client.get("/")
    assert resp.status_code == 200
    assert resp.headers["X-Foo"] == "a header"


def test_teardown_request_handler(app, client):
    called = []

    @app.teardown_request
    def teardown_request(exc):
        called.append(True)
        return "Ignored"

    @app.route("/")
    def root():
        return "Response"

    rv = client.get("/")
    assert rv.status_code == 200
    assert b"Response" in rv.data
    assert len(called) == 1


def test_teardown_request_handler_debug_mode(app, client):
    called = []

    @app.teardown_request
    def teardown_request(exc):
        called.append(True)
        return "Ignored"

    @app.route("/")
    def root():
        return "Response"

    rv = client.get("/")
    assert rv.status_code == 200
    assert b"Response" in rv.data
    assert len(called) == 1


def test_teardown_request_handler_error(app, client):
    called = []
    app.testing = False

    @app.teardown_request
    def teardown_request1(exc):
        assert type(exc) is ZeroDivisionError
        called.append(True)
        # This raises a new error and blows away sys.exc_info(), so we can
        # test that all teardown_requests get passed the same original
        # exception.
        try:
            raise TypeError()
        except Exception:
            pass

    @app.teardown_request
    def teardown_request2(exc):
        assert type(exc) is ZeroDivisionError
        called.append(True)
        # This raises a new error and blows away sys.exc_info(), so we can
        # test that all teardown_requests get passed the same original
        # exception.
        try:
            raise TypeError()
        except Exception:
            pass

    @app.route("/")
    def fails():
        raise ZeroDivisionError

    rv = client.get("/")
    assert rv.status_code == 500
    assert b"Internal Server Error" in rv.data
    assert len(called) == 2


def test_before_after_request_order(app, client):
    called = []

    @app.before_request
    def before1():
        called.append(1)

    @app.before_request
    def before2():
        called.append(2)

    @app.after_request
    def after1(response):
        called.append(4)
        return response

    @app.after_request
    def after2(response):
        called.append(3)
        return response

    @app.teardown_request
    def finish1(exc):
        called.append(6)

    @app.teardown_request
    def finish2(exc):
        called.append(5)

    @app.route("/")
    def index():
        return "42"

    rv = client.get("/")
    assert rv.data == b"42"
    assert called == [1, 2, 3, 4, 5, 6]


def test_error_handling(app, client):
    app.testing = False

    @app.errorhandler(404)
    def not_found(e):
        return "not found", 404

    @app.errorhandler(500)
    def internal_server_error(e):
        return "internal server error", 500

    @app.errorhandler(Forbidden)
    def forbidden(e):
        return "forbidden", 403

    @app.route("/")
    def index():
        flask.abort(404)

    @app.route("/error")
    def error():
        raise ZeroDivisionError

    @app.route("/forbidden")
    def error2():
        flask.abort(403)

    rv = client.get("/")
    assert rv.status_code == 404
    assert rv.data == b"not found"
    rv = client.get("/error")
    assert rv.status_code == 500
    assert b"internal server error" == rv.data
    rv = client.get("/forbidden")
    assert rv.status_code == 403
    assert b"forbidden" == rv.data


def test_error_handling_processing(app, client):
    app.testing = False

    @app.errorhandler(500)
    def internal_server_error(e):
        return "internal server error", 500

    @app.route("/")
    def broken_func():
        raise ZeroDivisionError

    @app.after_request
    def after_request(resp):
        resp.mimetype = "text/x-special"
        return resp

    resp = client.get("/")
    assert resp.mimetype == "text/x-special"
    assert resp.data == b"internal server error"


def test_baseexception_error_handling(app, client):
    app.testing = False

    @app.route("/")
    def broken_func():
        raise KeyboardInterrupt()

    with pytest.raises(KeyboardInterrupt):
        client.get("/")


def test_before_request_and_routing_errors(app, client):
    @app.before_request
    def attach_something():
        flask.g.something = "value"

    @app.errorhandler(404)
    def return_something(error):
        return flask.g.something, 404

    rv = client.get("/")
    assert rv.status_code == 404
    assert rv.data == b"value"


def test_user_error_handling(app, client):
    class MyException(Exception):
        pass

    @app.errorhandler(MyException)
    def handle_my_exception(e):
        assert isinstance(e, MyException)
        return "42"

    @app.route("/")
    def index():
        raise MyException()

    assert client.get("/").data == b"42"


def test_http_error_subclass_handling(app, client):
    class ForbiddenSubclass(Forbidden):
        pass

    @app.errorhandler(ForbiddenSubclass)
    def handle_forbidden_subclass(e):
        assert isinstance(e, ForbiddenSubclass)
        return "banana"

    @app.errorhandler(403)
    def handle_403(e):
        assert not isinstance(e, ForbiddenSubclass)
        assert isinstance(e, Forbidden)
        return "apple"

    @app.route("/1")
    def index1():
        raise ForbiddenSubclass()

    @app.route("/2")
    def index2():
        flask.abort(403)

    @app.route("/3")
    def index3():
        raise Forbidden()

    assert client.get("/1").data == b"banana"
    assert client.get("/2").data == b"apple"
    assert client.get("/3").data == b"apple"


def test_errorhandler_precedence(app, client):
    class E1(Exception):
        pass

    class E2(Exception):
        pass

    class E3(E1, E2):
        pass

    @app.errorhandler(E2)
    def handle_e2(e):
        return "E2"

    @app.errorhandler(Exception)
    def handle_exception(e):
        return "Exception"

    @app.route("/E1")
    def raise_e1():
        raise E1

    @app.route("/E3")
    def raise_e3():
        raise E3

    rv = client.get("/E1")
    assert rv.data == b"Exception"

    rv = client.get("/E3")
    assert rv.data == b"E2"


@pytest.mark.parametrize(
    ("debug", "trap", "expect_key", "expect_abort"),
    [(False, None, True, True), (True, None, False, True), (False, True, False, False)],
)
def test_trap_bad_request_key_error(app, client, debug, trap, expect_key, expect_abort):
    app.config["DEBUG"] = debug
    app.config["TRAP_BAD_REQUEST_ERRORS"] = trap

    @app.route("/key")
    def fail():
        flask.request.form["missing_key"]

    @app.route("/abort")
    def allow_abort():
        flask.abort(400)

    if expect_key:
        rv = client.get("/key")
        assert rv.status_code == 400
        assert b"missing_key" not in rv.data
    else:
        with pytest.raises(KeyError) as exc_info:
            client.get("/key")

        assert exc_info.errisinstance(BadRequest)
        assert "missing_key" in exc_info.value.get_description()

    if expect_abort:
        rv = client.get("/abort")
        assert rv.status_code == 400
    else:
        with pytest.raises(BadRequest):
            client.get("/abort")


def test_trapping_of_all_http_exceptions(app, client):
    app.config["TRAP_HTTP_EXCEPTIONS"] = True

    @app.route("/fail")
    def fail():
        flask.abort(404)

    with pytest.raises(NotFound):
        client.get("/fail")


def test_error_handler_after_processor_error(app, client):
    app.testing = False

    @app.before_request
    def before_request():
        if _trigger == "before":
            raise ZeroDivisionError

    @app.after_request
    def after_request(response):
        if _trigger == "after":
            raise ZeroDivisionError

        return response

    @app.route("/")
    def index():
        return "Foo"

    @app.errorhandler(500)
    def internal_server_error(e):
        return "Hello Server Error", 500

    for _trigger in "before", "after":
        rv = client.get("/")
        assert rv.status_code == 500
        assert rv.data == b"Hello Server Error"


def test_enctype_debug_helper(app, client):
    from flask.debughelpers import DebugFilesKeyError

    app.debug = True

    @app.route("/fail", methods=["POST"])
    def index():
        return flask.request.files["foo"].filename

    with pytest.raises(DebugFilesKeyError) as e:
        client.post("/fail", data={"foo": "index.txt"})
    assert "no file contents were transmitted" in str(e.value)
    assert "This was submitted: 'index.txt'" in str(e.value)


def test_response_types(app, client):
    @app.route("/text")
    def from_text():
        return "Hällo Wörld"

    @app.route("/bytes")
    def from_bytes():
        return "Hällo Wörld".encode()

    @app.route("/full_tuple")
    def from_full_tuple():
        return (
            "Meh",
            400,
            {"X-Foo": "Testing", "Content-Type": "text/plain; charset=utf-8"},
        )

    @app.route("/text_headers")
    def from_text_headers():
        return "Hello", {"X-Foo": "Test", "Content-Type": "text/plain; charset=utf-8"}

    @app.route("/text_status")
    def from_text_status():
        return "Hi, status!", 400

    @app.route("/response_headers")
    def from_response_headers():
        return (
            flask.Response(
                "Hello world", 404, {"Content-Type": "text/html", "X-Foo": "Baz"}
            ),
            {"Content-Type": "text/plain", "X-Foo": "Bar", "X-Bar": "Foo"},
        )

    @app.route("/response_status")
    def from_response_status():
        return app.response_class("Hello world", 400), 500

    @app.route("/wsgi")
    def from_wsgi():
        return NotFound()

    @app.route("/dict")
    def from_dict():
        return {"foo": "bar"}, 201

    @app.route("/list")
    def from_list():
        return ["foo", "bar"], 201

    assert client.get("/text").data == "Hällo Wörld".encode()
    assert client.get("/bytes").data == "Hällo Wörld".encode()

    rv = client.get("/full_tuple")
    assert rv.data == b"Meh"
    assert rv.headers["X-Foo"] == "Testing"
    assert rv.status_code == 400
    assert rv.mimetype == "text/plain"

    rv = client.get("/text_headers")
    assert rv.data == b"Hello"
    assert rv.headers["X-Foo"] == "Test"
    assert rv.status_code == 200
    assert rv.mimetype == "text/plain"

    rv = client.get("/text_status")
    assert rv.data == b"Hi, status!"
    assert rv.status_code == 400
    assert rv.mimetype == "text/html"

    rv = client.get("/response_headers")
    assert rv.data == b"Hello world"
    assert rv.content_type == "text/plain"
    assert rv.headers.getlist("X-Foo") == ["Bar"]
    assert rv.headers["X-Bar"] == "Foo"
    assert rv.status_code == 404

    rv = client.get("/response_status")
    assert rv.data == b"Hello world"
    assert rv.status_code == 500

    rv = client.get("/wsgi")
    assert b"Not Found" in rv.data
    assert rv.status_code == 404

    rv = client.get("/dict")
    assert rv.json == {"foo": "bar"}
    assert rv.status_code == 201

    rv = client.get("/list")
    assert rv.json == ["foo", "bar"]
    assert rv.status_code == 201


def test_response_type_errors():
    app = flask.Flask(__name__)
    app.testing = True

    @app.route("/none")
    def from_none():
        pass

    @app.route("/small_tuple")
    def from_small_tuple():
        return ("Hello",)

    @app.route("/large_tuple")
    def from_large_tuple():
        return "Hello", 234, {"X-Foo": "Bar"}, "???"

    @app.route("/bad_type")
    def from_bad_type():
        return True

    @app.route("/bad_wsgi")
    def from_bad_wsgi():
        return lambda: None

    c = app.test_client()

    with pytest.raises(TypeError) as e:
        c.get("/none")

    assert "returned None" in str(e.value)
    assert "from_none" in str(e.value)

    with pytest.raises(TypeError) as e:
        c.get("/small_tuple")

    assert "tuple must have the form" in str(e.value)

    with pytest.raises(TypeError):
        c.get("/large_tuple")

    with pytest.raises(TypeError) as e:
        c.get("/bad_type")

    assert "it was a bool" in str(e.value)

    with pytest.raises(TypeError):
        c.get("/bad_wsgi")


def test_make_response(app, req_ctx):
    rv = flask.make_response()
    assert rv.status_code == 200
    assert rv.data == b""
    assert rv.mimetype == "text/html"

    rv = flask.make_response("Awesome")
    assert rv.status_code == 200
    assert rv.data == b"Awesome"
    assert rv.mimetype == "text/html"

    rv = flask.make_response("W00t", 404)
    assert rv.status_code == 404
    assert rv.data == b"W00t"
    assert rv.mimetype == "text/html"

    rv = flask.make_response(c for c in "Hello")
    assert rv.status_code == 200
    assert rv.data == b"Hello"
    assert rv.mimetype == "text/html"


def test_make_response_with_response_instance(app, req_ctx):
    rv = flask.make_response(flask.jsonify({"msg": "W00t"}), 400)
    assert rv.status_code == 400
    assert rv.data == b'{"msg":"W00t"}\n'
    assert rv.mimetype == "application/json"

    rv = flask.make_response(flask.Response(""), 400)
    assert rv.status_code == 400
    assert rv.data == b""
    assert rv.mimetype == "text/html"

    rv = flask.make_response(
        flask.Response("", headers={"Content-Type": "text/html"}),
        400,
        [("X-Foo", "bar")],
    )
    assert rv.status_code == 400
    assert rv.headers["Content-Type"] == "text/html"
    assert rv.headers["X-Foo"] == "bar"


@pytest.mark.parametrize("compact", [True, False])
def test_jsonify_no_prettyprint(app, compact):
    app.json.compact = compact
    rv = app.json.response({"msg": {"submsg": "W00t"}, "msg2": "foobar"})
    data = rv.data.strip()
    assert (b" " not in data) is compact
    assert (b"\n" not in data) is compact


def test_jsonify_mimetype(app, req_ctx):
    app.json.mimetype = "application/vnd.api+json"
    msg = {"msg": {"submsg": "W00t"}}
    rv = flask.make_response(flask.jsonify(msg), 200)
    assert rv.mimetype == "application/vnd.api+json"


def test_json_dump_dataclass(app, req_ctx):
    from dataclasses import make_dataclass

    Data = make_dataclass("Data", [("name", str)])
    value = app.json.dumps(Data("Flask"))
    value = app.json.loads(value)
    assert value == {"name": "Flask"}


def test_jsonify_args_and_kwargs_check(app, req_ctx):
    with pytest.raises(TypeError) as e:
        flask.jsonify("fake args", kwargs="fake")
    assert "args or kwargs" in str(e.value)


def test_url_generation(app, req_ctx):
    @app.route("/hello/<name>", methods=["POST"])
    def hello():
        pass

    assert flask.url_for("hello", name="test x") == "/hello/test%20x"
    assert (
        flask.url_for("hello", name="test x", _external=True)
        == "http://localhost/hello/test%20x"
    )


def test_build_error_handler(app):
    # Test base case, a URL which results in a BuildError.
    with app.test_request_context():
        pytest.raises(BuildError, flask.url_for, "spam")

    # Verify the error is re-raised if not the current exception.
    try:
        with app.test_request_context():
            flask.url_for("spam")
    except BuildError as err:
        error = err
    try:
        raise RuntimeError("Test case where BuildError is not current.")
    except RuntimeError:
        pytest.raises(BuildError, app.handle_url_build_error, error, "spam", {})

    # Test a custom handler.
    def handler(error, endpoint, values):
        # Just a test.
        return "/test_handler/"

    app.url_build_error_handlers.append(handler)
    with app.test_request_context():
        assert flask.url_for("spam") == "/test_handler/"


def test_build_error_handler_reraise(app):
    # Test a custom handler which reraises the BuildError
    def handler_raises_build_error(error, endpoint, values):
        raise error

    app.url_build_error_handlers.append(handler_raises_build_error)

    with app.test_request_context():
        pytest.raises(BuildError, flask.url_for, "not.existing")


def test_url_for_passes_special_values_to_build_error_handler(app):
    @app.url_build_error_handlers.append
    def handler(error, endpoint, values):
        assert values == {
            "_external": False,
            "_anchor": None,
            "_method": None,
            "_scheme": None,
        }
        return "handled"

    with app.test_request_context():
        flask.url_for("/")


def test_static_files(app, client):
    rv = client.get("/static/index.html")
    assert rv.status_code == 200
    assert rv.data.strip() == b"<h1>Hello World!</h1>"
    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/static/index.html"
    rv.close()


def test_static_url_path():
    app = flask.Flask(__name__, static_url_path="/foo")
    app.testing = True
    rv = app.test_client().get("/foo/index.html")
    assert rv.status_code == 200
    rv.close()

    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/foo/index.html"


def test_static_url_path_with_ending_slash():
    app = flask.Flask(__name__, static_url_path="/foo/")
    app.testing = True
    rv = app.test_client().get("/foo/index.html")
    assert rv.status_code == 200
    rv.close()

    with app.test_request_context():
        assert flask.url_for("static", filename="index.html") == "/foo/index.html"


def test_static_url_empty_path(app):
    app = flask.Flask(__name__, static_folder="", static_url_path="")
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_url_empty_path_default(app):
    app = flask.Flask(__name__, static_folder="")
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_folder_with_pathlib_path(app):
    from pathlib import Path

    app = flask.Flask(__name__, static_folder=Path("static"))
    rv = app.test_client().open("/static/index.html", method="GET")
    assert rv.status_code == 200
    rv.close()


def test_static_folder_with_ending_slash():
    app = flask.Flask(__name__, static_folder="static/")

    @app.route("/<path:path>")
    def catch_all(path):
        return path

    rv = app.test_client().get("/catch/all")
    assert rv.data == b"catch/all"


def test_static_route_with_host_matching():
    app = flask.Flask(__name__, host_matching=True, static_host="example.com")
    c = app.test_client()
    rv = c.get("http://example.com/static/index.html")
    assert rv.status_code == 200
    rv.close()
    with app.test_request_context():
        rv = flask.url_for("static", filename="index.html", _external=True)
        assert rv == "http://example.com/static/index.html"
    # Providing static_host without host_matching=True should error.
    with pytest.raises(AssertionError):
        flask.Flask(__name__, static_host="example.com")
    # Providing host_matching=True with static_folder
    # but without static_host should error.
    with pytest.raises(AssertionError):
        flask.Flask(__name__, host_matching=True)
    # Providing host_matching=True without static_host
    # but with static_folder=None should not error.
    flask.Flask(__name__, host_matching=True, static_folder=None)


def test_request_locals():
    assert repr(flask.g) == "<LocalProxy unbound>"
    assert not flask.g


def test_server_name_subdomain():
    app = flask.Flask(__name__, subdomain_matching=True)
    client = app.test_client()

    @app.route("/")
    def index():
        return "default"

    @app.route("/", subdomain="foo")
    def subdomain():
        return "subdomain"

    app.config["SERVER_NAME"] = "dev.local:5000"
    rv = client.get("/")
    assert rv.data == b"default"

    rv = client.get("/", "http://dev.local:5000")
    assert rv.data == b"default"

    rv = client.get("/", "https://dev.local:5000")
    assert rv.data == b"default"

    app.config["SERVER_NAME"] = "dev.local:443"
    rv = client.get("/", "https://dev.local")

    # Werkzeug 1.0 fixes matching https scheme with 443 port
    if rv.status_code != 404:
        assert rv.data == b"default"

    app.config["SERVER_NAME"] = "dev.local"
    rv = client.get("/", "https://dev.local")
    assert rv.data == b"default"

    # suppress Werkzeug 0.15 warning about name mismatch
    with warnings.catch_warnings():
        warnings.filterwarnings(
            "ignore", "Current server name", UserWarning, "flask.app"
        )
        rv = client.get("/", "http://foo.localhost")
        assert rv.status_code == 404

    rv = client.get("/", "http://foo.dev.local")
    assert rv.data == b"subdomain"


@pytest.mark.parametrize("key", ["TESTING", "PROPAGATE_EXCEPTIONS", "DEBUG", None])
def test_exception_propagation(app, client, key):
    app.testing = False

    @app.route("/")
    def index():
        raise ZeroDivisionError

    if key is not None:
        app.config[key] = True

        with pytest.raises(ZeroDivisionError):
            client.get("/")
    else:
        assert client.get("/").status_code == 500


@pytest.mark.parametrize("debug", [True, False])
@pytest.mark.parametrize("use_debugger", [True, False])
@pytest.mark.parametrize("use_reloader", [True, False])
@pytest.mark.parametrize("propagate_exceptions", [None, True, False])
def test_werkzeug_passthrough_errors(
    monkeypatch, debug, use_debugger, use_reloader, propagate_exceptions, app
):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(*args, **kwargs):
        rv["passthrough_errors"] = kwargs.get("passthrough_errors")

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.config["PROPAGATE_EXCEPTIONS"] = propagate_exceptions
    app.run(debug=debug, use_debugger=use_debugger, use_reloader=use_reloader)


def test_max_content_length(app, client):
    app.config["MAX_CONTENT_LENGTH"] = 64

    @app.before_request
    def always_first():
        flask.request.form["myfile"]
        AssertionError()

    @app.route("/accept", methods=["POST"])
    def accept_file():
        flask.request.form["myfile"]
        AssertionError()

    @app.errorhandler(413)
    def catcher(error):
        return "42"

    rv = client.post("/accept", data={"myfile": "foo" * 100})
    assert rv.data == b"42"


def test_url_processors(app, client):
    @app.url_defaults
    def add_language_code(endpoint, values):
        if flask.g.lang_code is not None and app.url_map.is_endpoint_expecting(
            endpoint, "lang_code"
        ):
            values.setdefault("lang_code", flask.g.lang_code)

    @app.url_value_preprocessor
    def pull_lang_code(endpoint, values):
        flask.g.lang_code = values.pop("lang_code", None)

    @app.route("/<lang_code>/")
    def index():
        return flask.url_for("about")

    @app.route("/<lang_code>/about")
    def about():
        return flask.url_for("something_else")

    @app.route("/foo")
    def something_else():
        return flask.url_for("about", lang_code="en")

    assert client.get("/de/").data == b"/de/about"
    assert client.get("/de/about").data == b"/foo"
    assert client.get("/foo").data == b"/en/about"


def test_inject_blueprint_url_defaults(app):
    bp = flask.Blueprint("foo", __name__, template_folder="template")

    @bp.url_defaults
    def bp_defaults(endpoint, values):
        values["page"] = "login"

    @bp.route("/<page>")
    def view(page):
        pass

    app.register_blueprint(bp)

    values = dict()
    app.inject_url_defaults("foo.view", values)
    expected = dict(page="login")
    assert values == expected

    with app.test_request_context("/somepage"):
        url = flask.url_for("foo.view")
    expected = "/login"
    assert url == expected


def test_nonascii_pathinfo(app, client):
    @app.route("/киртест")
    def index():
        return "Hello World!"

    rv = client.get("/киртест")
    assert rv.data == b"Hello World!"


def test_no_setup_after_first_request(app, client):
    app.debug = True

    @app.route("/")
    def index():
        return "Awesome"

    assert client.get("/").data == b"Awesome"

    with pytest.raises(AssertionError) as exc_info:
        app.add_url_rule("/foo", endpoint="late")

    assert "setup method 'add_url_rule'" in str(exc_info.value)


def test_routing_redirect_debugging(monkeypatch, app, client):
    app.config["DEBUG"] = True

    @app.route("/user/", methods=["GET", "POST"])
    def user():
        return flask.request.form["status"]

    # default redirect code preserves form data
    rv = client.post("/user", data={"status": "success"}, follow_redirects=True)
    assert rv.data == b"success"

    # 301 and 302 raise error
    monkeypatch.setattr(RequestRedirect, "code", 301)

    with client, pytest.raises(AssertionError) as exc_info:
        client.post("/user", data={"status": "error"}, follow_redirects=True)

    assert "canonical URL 'http://localhost/user/'" in str(exc_info.value)


def test_route_decorator_custom_endpoint(app, client):
    app.debug = True

    @app.route("/foo/")
    def foo():
        return flask.request.endpoint

    @app.route("/bar/", endpoint="bar")
    def for_bar():
        return flask.request.endpoint

    @app.route("/bar/123", endpoint="123")
    def for_bar_foo():
        return flask.request.endpoint

    with app.test_request_context():
        assert flask.url_for("foo") == "/foo/"
        assert flask.url_for("bar") == "/bar/"
        assert flask.url_for("123") == "/bar/123"

    assert client.get("/foo/").data == b"foo"
    assert client.get("/bar/").data == b"bar"
    assert client.get("/bar/123").data == b"123"


def test_get_method_on_g(app_ctx):
    assert flask.g.get("x") is None
    assert flask.g.get("x", 11) == 11
    flask.g.x = 42
    assert flask.g.get("x") == 42
    assert flask.g.x == 42


def test_g_iteration_protocol(app_ctx):
    flask.g.foo = 23
    flask.g.bar = 42
    assert "foo" in flask.g
    assert "foos" not in flask.g
    assert sorted(flask.g) == ["bar", "foo"]


def test_subdomain_basic_support():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "localhost.localdomain"
    client = app.test_client()

    @app.route("/")
    def normal_index():
        return "normal index"

    @app.route("/", subdomain="test")
    def test_index():
        return "test index"

    rv = client.get("/", "http://localhost.localdomain/")
    assert rv.data == b"normal index"

    rv = client.get("/", "http://test.localhost.localdomain/")
    assert rv.data == b"test index"


def test_subdomain_matching():
    app = flask.Flask(__name__, subdomain_matching=True)
    client = app.test_client()
    app.config["SERVER_NAME"] = "localhost.localdomain"

    @app.route("/", subdomain="<user>")
    def index(user):
        return f"index for {user}"

    rv = client.get("/", "http://mitsuhiko.localhost.localdomain/")
    assert rv.data == b"index for mitsuhiko"


def test_subdomain_matching_with_ports():
    app = flask.Flask(__name__, subdomain_matching=True)
    app.config["SERVER_NAME"] = "localhost.localdomain:3000"
    client = app.test_client()

    @app.route("/", subdomain="<user>")
    def index(user):
        return f"index for {user}"

    rv = client.get("/", "http://mitsuhiko.localhost.localdomain:3000/")
    assert rv.data == b"index for mitsuhiko"


@pytest.mark.parametrize("matching", (False, True))
def test_subdomain_matching_other_name(matching):
    app = flask.Flask(__name__, subdomain_matching=matching)
    app.config["SERVER_NAME"] = "localhost.localdomain:3000"
    client = app.test_client()

    @app.route("/")
    def index():
        return "", 204

    # suppress Werkzeug 0.15 warning about name mismatch
    with warnings.catch_warnings():
        warnings.filterwarnings(
            "ignore", "Current server name", UserWarning, "flask.app"
        )
        # ip address can't match name
        rv = client.get("/", "http://127.0.0.1:3000/")
        assert rv.status_code == 404 if matching else 204

    # allow all subdomains if matching is disabled
    rv = client.get("/", "http://www.localhost.localdomain:3000/")
    assert rv.status_code == 404 if matching else 204


def test_multi_route_rules(app, client):
    @app.route("/")
    @app.route("/<test>/")
    def index(test="a"):
        return test

    rv = client.open("/")
    assert rv.data == b"a"
    rv = client.open("/b/")
    assert rv.data == b"b"


def test_multi_route_class_views(app, client):
    class View:
        def __init__(self, app):
            app.add_url_rule("/", "index", self.index)
            app.add_url_rule("/<test>/", "index", self.index)

        def index(self, test="a"):
            return test

    _ = View(app)
    rv = client.open("/")
    assert rv.data == b"a"
    rv = client.open("/b/")
    assert rv.data == b"b"


def test_run_defaults(monkeypatch, app):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(*args, **kwargs):
        rv["result"] = "running..."

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.run()
    assert rv["result"] == "running..."


def test_run_server_port(monkeypatch, app):
    rv = {}

    # Mocks werkzeug.serving.run_simple method
    def run_simple_mock(hostname, port, application, *args, **kwargs):
        rv["result"] = f"running on {hostname}:{port} ..."

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    hostname, port = "localhost", 8000
    app.run(hostname, port, debug=True)
    assert rv["result"] == f"running on {hostname}:{port} ..."


@pytest.mark.parametrize(
    "host,port,server_name,expect_host,expect_port",
    (
        (None, None, "pocoo.org:8080", "pocoo.org", 8080),
        ("localhost", None, "pocoo.org:8080", "localhost", 8080),
        (None, 80, "pocoo.org:8080", "pocoo.org", 80),
        ("localhost", 80, "pocoo.org:8080", "localhost", 80),
        ("localhost", 0, "localhost:8080", "localhost", 0),
        (None, None, "localhost:8080", "localhost", 8080),
        (None, None, "localhost:0", "localhost", 0),
    ),
)
def test_run_from_config(
    monkeypatch, host, port, server_name, expect_host, expect_port, app
):
    def run_simple_mock(hostname, port, *args, **kwargs):
        assert hostname == expect_host
        assert port == expect_port

    monkeypatch.setattr(werkzeug.serving, "run_simple", run_simple_mock)
    app.config["SERVER_NAME"] = server_name
    app.run(host, port)


def test_max_cookie_size(app, client, recwarn):
    app.config["MAX_COOKIE_SIZE"] = 100

    # outside app context, default to Werkzeug static value,
    # which is also the default config
    response = flask.Response()
    default = flask.Flask.default_config["MAX_COOKIE_SIZE"]
    assert response.max_cookie_size == default

    # inside app context, use app config
    with app.app_context():
        assert flask.Response().max_cookie_size == 100

    @app.route("/")
    def index():
        r = flask.Response("", status=204)
        r.set_cookie("foo", "bar" * 100)
        return r

    client.get("/")
    assert len(recwarn) == 1
    w = recwarn.pop()
    assert "cookie is too large" in str(w.message)

    app.config["MAX_COOKIE_SIZE"] = 0

    client.get("/")
    assert len(recwarn) == 0


@require_cpython_gc
def test_app_freed_on_zero_refcount():
    # A Flask instance should not create a reference cycle that prevents CPython
    # from freeing it when all external references to it are released (see #3761).
    gc.disable()
    try:
        app = flask.Flask(__name__)
        assert app.view_functions["static"]
        weak = weakref.ref(app)
        assert weak() is not None
        del app
        assert weak() is None
    finally:
        gc.enable()