add ydb deps

1 files changed, 2091 insertions, 0 deletions

diff --git a/contrib/python/Flask/py3/flask/app.py b/contrib/python/Flask/py3/flask/app.py
new file mode 100644
index 00000000000..23b99e2ca08
--- /dev/null
+++ b/contrib/python/Flask/py3/flask/app.py
@@ -0,0 +1,2091 @@
+import functools
+import inspect
+import logging
+import os
+import sys
+import typing as t
+import weakref
+from datetime import timedelta
+from itertools import chain
+from threading import Lock
+from types import TracebackType
+
+from werkzeug.datastructures import Headers
+from werkzeug.datastructures import ImmutableDict
+from werkzeug.exceptions import BadRequest
+from werkzeug.exceptions import BadRequestKeyError
+from werkzeug.exceptions import HTTPException
+from werkzeug.exceptions import InternalServerError
+from werkzeug.local import ContextVar
+from werkzeug.routing import BuildError
+from werkzeug.routing import Map
+from werkzeug.routing import MapAdapter
+from werkzeug.routing import RequestRedirect
+from werkzeug.routing import RoutingException
+from werkzeug.routing import Rule
+from werkzeug.wrappers import Response as BaseResponse
+
+from . import cli
+from . import json
+from .config import Config
+from .config import ConfigAttribute
+from .ctx import _AppCtxGlobals
+from .ctx import AppContext
+from .ctx import RequestContext
+from .globals import _request_ctx_stack
+from .globals import g
+from .globals import request
+from .globals import session
+from .helpers import _split_blueprint_path
+from .helpers import get_debug_flag
+from .helpers import get_env
+from .helpers import get_flashed_messages
+from .helpers import get_load_dotenv
+from .helpers import locked_cached_property
+from .helpers import url_for
+from .json import jsonify
+from .logging import create_logger
+from .scaffold import _endpoint_from_view_func
+from .scaffold import _sentinel
+from .scaffold import find_package
+from .scaffold import Scaffold
+from .scaffold import setupmethod
+from .sessions import SecureCookieSessionInterface
+from .signals import appcontext_tearing_down
+from .signals import got_request_exception
+from .signals import request_finished
+from .signals import request_started
+from .signals import request_tearing_down
+from .templating import DispatchingJinjaLoader
+from .templating import Environment
+from .typing import BeforeFirstRequestCallable
+from .typing import ResponseReturnValue
+from .typing import TeardownCallable
+from .typing import TemplateFilterCallable
+from .typing import TemplateGlobalCallable
+from .typing import TemplateTestCallable
+from .wrappers import Request
+from .wrappers import Response
+
+if t.TYPE_CHECKING:
+    import typing_extensions as te
+    from .blueprints import Blueprint
+    from .testing import FlaskClient
+    from .testing import FlaskCliRunner
+    from .typing import ErrorHandlerCallable
+
+if sys.version_info >= (3, 8):
+    iscoroutinefunction = inspect.iscoroutinefunction
+else:
+
+    def iscoroutinefunction(func: t.Any) -> bool:
+        while inspect.ismethod(func):
+            func = func.__func__
+
+        while isinstance(func, functools.partial):
+            func = func.func
+
+        return inspect.iscoroutinefunction(func)
+
+
+def _make_timedelta(value: t.Optional[timedelta]) -> t.Optional[timedelta]:
+    if value is None or isinstance(value, timedelta):
+        return value
+
+    return timedelta(seconds=value)
+
+
+class Flask(Scaffold):
+    """The flask object implements a WSGI application and acts as the central
+    object.  It is passed the name of the module or package of the
+    application.  Once it is created it will act as a central registry for
+    the view functions, the URL rules, template configuration and much more.
+
+    The name of the package is used to resolve resources from inside the
+    package or the folder the module is contained in depending on if the
+    package parameter resolves to an actual python package (a folder with
+    an :file:`__init__.py` file inside) or a standard module (just a ``.py`` file).
+
+    For more information about resource loading, see :func:`open_resource`.
+
+    Usually you create a :class:`Flask` instance in your main module or
+    in the :file:`__init__.py` file of your package like this::
+
+        from flask import Flask
+        app = Flask(__name__)
+
+    .. admonition:: About the First Parameter
+
+        The idea of the first parameter is to give Flask an idea of what
+        belongs to your application.  This name is used to find resources
+        on the filesystem, can be used by extensions to improve debugging
+        information and a lot more.
+
+        So it's important what you provide there.  If you are using a single
+        module, `__name__` is always the correct value.  If you however are
+        using a package, it's usually recommended to hardcode the name of
+        your package there.
+
+        For example if your application is defined in :file:`yourapplication/app.py`
+        you should create it with one of the two versions below::
+
+            app = Flask('yourapplication')
+            app = Flask(__name__.split('.')[0])
+
+        Why is that?  The application will work even with `__name__`, thanks
+        to how resources are looked up.  However it will make debugging more
+        painful.  Certain extensions can make assumptions based on the
+        import name of your application.  For example the Flask-SQLAlchemy
+        extension will look for the code in your application that triggered
+        an SQL query in debug mode.  If the import name is not properly set
+        up, that debugging information is lost.  (For example it would only
+        pick up SQL queries in `yourapplication.app` and not
+        `yourapplication.views.frontend`)
+
+    .. versionadded:: 0.7
+       The `static_url_path`, `static_folder`, and `template_folder`
+       parameters were added.
+
+    .. versionadded:: 0.8
+       The `instance_path` and `instance_relative_config` parameters were
+       added.
+
+    .. versionadded:: 0.11
+       The `root_path` parameter was added.
+
+    .. versionadded:: 1.0
+       The ``host_matching`` and ``static_host`` parameters were added.
+
+    .. versionadded:: 1.0
+       The ``subdomain_matching`` parameter was added. Subdomain
+       matching needs to be enabled manually now. Setting
+       :data:`SERVER_NAME` does not implicitly enable it.
+
+    :param import_name: the name of the application package
+    :param static_url_path: can be used to specify a different path for the
+                            static files on the web.  Defaults to the name
+                            of the `static_folder` folder.
+    :param static_folder: The folder with static files that is served at
+        ``static_url_path``. Relative to the application ``root_path``
+        or an absolute path. Defaults to ``'static'``.
+    :param static_host: the host to use when adding the static route.
+        Defaults to None. Required when using ``host_matching=True``
+        with a ``static_folder`` configured.
+    :param host_matching: set ``url_map.host_matching`` attribute.
+        Defaults to False.
+    :param subdomain_matching: consider the subdomain relative to
+        :data:`SERVER_NAME` when matching routes. Defaults to False.
+    :param template_folder: the folder that contains the templates that should
+                            be used by the application.  Defaults to
+                            ``'templates'`` folder in the root path of the
+                            application.
+    :param instance_path: An alternative instance path for the application.
+                          By default the folder ``'instance'`` next to the
+                          package or module is assumed to be the instance
+                          path.
+    :param instance_relative_config: if set to ``True`` relative filenames
+                                     for loading the config are assumed to
+                                     be relative to the instance path instead
+                                     of the application root.
+    :param root_path: The path to the root of the application files.
+        This should only be set manually when it can't be detected
+        automatically, such as for namespace packages.
+    """
+
+    #: The class that is used for request objects.  See :class:`~flask.Request`
+    #: for more information.
+    request_class = Request
+
+    #: The class that is used for response objects.  See
+    #: :class:`~flask.Response` for more information.
+    response_class = Response
+
+    #: The class that is used for the Jinja environment.
+    #:
+    #: .. versionadded:: 0.11
+    jinja_environment = Environment
+
+    #: The class that is used for the :data:`~flask.g` instance.
+    #:
+    #: Example use cases for a custom class:
+    #:
+    #: 1. Store arbitrary attributes on flask.g.
+    #: 2. Add a property for lazy per-request database connectors.
+    #: 3. Return None instead of AttributeError on unexpected attributes.
+    #: 4. Raise exception if an unexpected attr is set, a "controlled" flask.g.
+    #:
+    #: In Flask 0.9 this property was called `request_globals_class` but it
+    #: was changed in 0.10 to :attr:`app_ctx_globals_class` because the
+    #: flask.g object is now application context scoped.
+    #:
+    #: .. versionadded:: 0.10
+    app_ctx_globals_class = _AppCtxGlobals
+
+    #: The class that is used for the ``config`` attribute of this app.
+    #: Defaults to :class:`~flask.Config`.
+    #:
+    #: Example use cases for a custom class:
+    #:
+    #: 1. Default values for certain config options.
+    #: 2. Access to config values through attributes in addition to keys.
+    #:
+    #: .. versionadded:: 0.11
+    config_class = Config
+
+    #: The testing flag.  Set this to ``True`` to enable the test mode of
+    #: Flask extensions (and in the future probably also Flask itself).
+    #: For example this might activate test helpers that have an
+    #: additional runtime cost which should not be enabled by default.
+    #:
+    #: If this is enabled and PROPAGATE_EXCEPTIONS is not changed from the
+    #: default it's implicitly enabled.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``TESTING`` configuration key.  Defaults to ``False``.
+    testing = ConfigAttribute("TESTING")
+
+    #: If a secret key is set, cryptographic components can use this to
+    #: sign cookies and other things. Set this to a complex random value
+    #: when you want to use the secure cookie for instance.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: :data:`SECRET_KEY` configuration key. Defaults to ``None``.
+    secret_key = ConfigAttribute("SECRET_KEY")
+
+    #: The secure cookie uses this for the name of the session cookie.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``SESSION_COOKIE_NAME`` configuration key.  Defaults to ``'session'``
+    session_cookie_name = ConfigAttribute("SESSION_COOKIE_NAME")
+
+    #: A :class:`~datetime.timedelta` which is used to set the expiration
+    #: date of a permanent session.  The default is 31 days which makes a
+    #: permanent session survive for roughly one month.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``PERMANENT_SESSION_LIFETIME`` configuration key.  Defaults to
+    #: ``timedelta(days=31)``
+    permanent_session_lifetime = ConfigAttribute(
+        "PERMANENT_SESSION_LIFETIME", get_converter=_make_timedelta
+    )
+
+    #: A :class:`~datetime.timedelta` or number of seconds which is used
+    #: as the default ``max_age`` for :func:`send_file`. The default is
+    #: ``None``, which tells the browser to use conditional requests
+    #: instead of a timed cache.
+    #:
+    #: Configured with the :data:`SEND_FILE_MAX_AGE_DEFAULT`
+    #: configuration key.
+    #:
+    #: .. versionchanged:: 2.0
+    #:     Defaults to ``None`` instead of 12 hours.
+    send_file_max_age_default = ConfigAttribute(
+        "SEND_FILE_MAX_AGE_DEFAULT", get_converter=_make_timedelta
+    )
+
+    #: Enable this if you want to use the X-Sendfile feature.  Keep in
+    #: mind that the server has to support this.  This only affects files
+    #: sent with the :func:`send_file` method.
+    #:
+    #: .. versionadded:: 0.2
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``USE_X_SENDFILE`` configuration key.  Defaults to ``False``.
+    use_x_sendfile = ConfigAttribute("USE_X_SENDFILE")
+
+    #: The JSON encoder class to use.  Defaults to :class:`~flask.json.JSONEncoder`.
+    #:
+    #: .. versionadded:: 0.10
+    json_encoder = json.JSONEncoder
+
+    #: The JSON decoder class to use.  Defaults to :class:`~flask.json.JSONDecoder`.
+    #:
+    #: .. versionadded:: 0.10
+    json_decoder = json.JSONDecoder
+
+    #: Options that are passed to the Jinja environment in
+    #: :meth:`create_jinja_environment`. Changing these options after
+    #: the environment is created (accessing :attr:`jinja_env`) will
+    #: have no effect.
+    #:
+    #: .. versionchanged:: 1.1.0
+    #:     This is a ``dict`` instead of an ``ImmutableDict`` to allow
+    #:     easier configuration.
+    #:
+    jinja_options: dict = {}
+
+    #: Default configuration parameters.
+    default_config = ImmutableDict(
+        {
+            "ENV": None,
+            "DEBUG": None,
+            "TESTING": False,
+            "PROPAGATE_EXCEPTIONS": None,
+            "PRESERVE_CONTEXT_ON_EXCEPTION": None,
+            "SECRET_KEY": None,
+            "PERMANENT_SESSION_LIFETIME": timedelta(days=31),
+            "USE_X_SENDFILE": False,
+            "SERVER_NAME": None,
+            "APPLICATION_ROOT": "/",
+            "SESSION_COOKIE_NAME": "session",
+            "SESSION_COOKIE_DOMAIN": None,
+            "SESSION_COOKIE_PATH": None,
+            "SESSION_COOKIE_HTTPONLY": True,
+            "SESSION_COOKIE_SECURE": False,
+            "SESSION_COOKIE_SAMESITE": None,
+            "SESSION_REFRESH_EACH_REQUEST": True,
+            "MAX_CONTENT_LENGTH": None,
+            "SEND_FILE_MAX_AGE_DEFAULT": None,
+            "TRAP_BAD_REQUEST_ERRORS": None,
+            "TRAP_HTTP_EXCEPTIONS": False,
+            "EXPLAIN_TEMPLATE_LOADING": False,
+            "PREFERRED_URL_SCHEME": "http",
+            "JSON_AS_ASCII": True,
+            "JSON_SORT_KEYS": True,
+            "JSONIFY_PRETTYPRINT_REGULAR": False,
+            "JSONIFY_MIMETYPE": "application/json",
+            "TEMPLATES_AUTO_RELOAD": None,
+            "MAX_COOKIE_SIZE": 4093,
+        }
+    )
+
+    #: The rule object to use for URL rules created.  This is used by
+    #: :meth:`add_url_rule`.  Defaults to :class:`werkzeug.routing.Rule`.
+    #:
+    #: .. versionadded:: 0.7
+    url_rule_class = Rule
+
+    #: The map object to use for storing the URL rules and routing
+    #: configuration parameters. Defaults to :class:`werkzeug.routing.Map`.
+    #:
+    #: .. versionadded:: 1.1.0
+    url_map_class = Map
+
+    #: The :meth:`test_client` method creates an instance of this test
+    #: client class. Defaults to :class:`~flask.testing.FlaskClient`.
+    #:
+    #: .. versionadded:: 0.7
+    test_client_class: t.Optional[t.Type["FlaskClient"]] = None
+
+    #: The :class:`~click.testing.CliRunner` subclass, by default
+    #: :class:`~flask.testing.FlaskCliRunner` that is used by
+    #: :meth:`test_cli_runner`. Its ``__init__`` method should take a
+    #: Flask app object as the first argument.
+    #:
+    #: .. versionadded:: 1.0
+    test_cli_runner_class: t.Optional[t.Type["FlaskCliRunner"]] = None
+
+    #: the session interface to use.  By default an instance of
+    #: :class:`~flask.sessions.SecureCookieSessionInterface` is used here.
+    #:
+    #: .. versionadded:: 0.8
+    session_interface = SecureCookieSessionInterface()
+
+    def __init__(
+        self,
+        import_name: str,
+        static_url_path: t.Optional[str] = None,
+        static_folder: t.Optional[t.Union[str, os.PathLike]] = "static",
+        static_host: t.Optional[str] = None,
+        host_matching: bool = False,
+        subdomain_matching: bool = False,
+        template_folder: t.Optional[str] = "templates",
+        instance_path: t.Optional[str] = None,
+        instance_relative_config: bool = False,
+        root_path: t.Optional[str] = None,
+    ):
+        super().__init__(
+            import_name=import_name,
+            static_folder=static_folder,
+            static_url_path=static_url_path,
+            template_folder=template_folder,
+            root_path=root_path,
+        )
+
+        if instance_path is None:
+            instance_path = self.auto_find_instance_path()
+        elif not os.path.isabs(instance_path):
+            raise ValueError(
+                "If an instance path is provided it must be absolute."
+                " A relative path was given instead."
+            )
+
+        #: Holds the path to the instance folder.
+        #:
+        #: .. versionadded:: 0.8
+        self.instance_path = instance_path
+
+        #: The configuration dictionary as :class:`Config`.  This behaves
+        #: exactly like a regular dictionary but supports additional methods
+        #: to load a config from files.
+        self.config = self.make_config(instance_relative_config)
+
+        #: A list of functions that are called when :meth:`url_for` raises a
+        #: :exc:`~werkzeug.routing.BuildError`.  Each function registered here
+        #: is called with `error`, `endpoint` and `values`.  If a function
+        #: returns ``None`` or raises a :exc:`BuildError` the next function is
+        #: tried.
+        #:
+        #: .. versionadded:: 0.9
+        self.url_build_error_handlers: t.List[
+            t.Callable[[Exception, str, dict], str]
+        ] = []
+
+        #: A list of functions that will be called at the beginning of the
+        #: first request to this instance. To register a function, use the
+        #: :meth:`before_first_request` decorator.
+        #:
+        #: .. versionadded:: 0.8
+        self.before_first_request_funcs: t.List[BeforeFirstRequestCallable] = []
+
+        #: A list of functions that are called when the application context
+        #: is destroyed.  Since the application context is also torn down
+        #: if the request ends this is the place to store code that disconnects
+        #: from databases.
+        #:
+        #: .. versionadded:: 0.9
+        self.teardown_appcontext_funcs: t.List[TeardownCallable] = []
+
+        #: A list of shell context processor functions that should be run
+        #: when a shell context is created.
+        #:
+        #: .. versionadded:: 0.11
+        self.shell_context_processors: t.List[t.Callable[[], t.Dict[str, t.Any]]] = []
+
+        #: Maps registered blueprint names to blueprint objects. The
+        #: dict retains the order the blueprints were registered in.
+        #: Blueprints can be registered multiple times, this dict does
+        #: not track how often they were attached.
+        #:
+        #: .. versionadded:: 0.7
+        self.blueprints: t.Dict[str, "Blueprint"] = {}
+
+        #: a place where extensions can store application specific state.  For
+        #: example this is where an extension could store database engines and
+        #: similar things.
+        #:
+        #: The key must match the name of the extension module. For example in
+        #: case of a "Flask-Foo" extension in `flask_foo`, the key would be
+        #: ``'foo'``.
+        #:
+        #: .. versionadded:: 0.7
+        self.extensions: dict = {}
+
+        #: The :class:`~werkzeug.routing.Map` for this instance.  You can use
+        #: this to change the routing converters after the class was created
+        #: but before any routes are connected.  Example::
+        #:
+        #:    from werkzeug.routing import BaseConverter
+        #:
+        #:    class ListConverter(BaseConverter):
+        #:        def to_python(self, value):
+        #:            return value.split(',')
+        #:        def to_url(self, values):
+        #:            return ','.join(super(ListConverter, self).to_url(value)
+        #:                            for value in values)
+        #:
+        #:    app = Flask(__name__)
+        #:    app.url_map.converters['list'] = ListConverter
+        self.url_map = self.url_map_class()
+
+        self.url_map.host_matching = host_matching
+        self.subdomain_matching = subdomain_matching
+
+        # tracks internally if the application already handled at least one
+        # request.
+        self._got_first_request = False
+        self._before_request_lock = Lock()
+
+        # Add a static route using the provided static_url_path, static_host,
+        # and static_folder if there is a configured static_folder.
+        # Note we do this without checking if static_folder exists.
+        # For one, it might be created while the server is running (e.g. during
+        # development). Also, Google App Engine stores static files somewhere
+        if self.has_static_folder:
+            assert (
+                bool(static_host) == host_matching
+            ), "Invalid static_host/host_matching combination"
+            # Use a weakref to avoid creating a reference cycle between the app
+            # and the view function (see #3761).
+            self_ref = weakref.ref(self)
+            self.add_url_rule(
+                f"{self.static_url_path}/<path:filename>",
+                endpoint="static",
+                host=static_host,
+                view_func=lambda **kw: self_ref().send_static_file(**kw),  # type: ignore # noqa: B950
+            )
+
+        # Set the name of the Click group in case someone wants to add
+        # the app's commands to another CLI tool.
+        self.cli.name = self.name
+
+    def _is_setup_finished(self) -> bool:
+        return self.debug and self._got_first_request
+
+    @locked_cached_property
+    def name(self) -> str:  # type: ignore
+        """The name of the application.  This is usually the import name
+        with the difference that it's guessed from the run file if the
+        import name is main.  This name is used as a display name when
+        Flask needs the name of the application.  It can be set and overridden
+        to change the value.
+
+        .. versionadded:: 0.8
+        """
+        if self.import_name == "__main__":
+            fn = getattr(sys.modules["__main__"], "__file__", None)
+            if fn is None:
+                return "__main__"
+            return os.path.splitext(os.path.basename(fn))[0]
+        return self.import_name
+
+    @property
+    def propagate_exceptions(self) -> bool:
+        """Returns the value of the ``PROPAGATE_EXCEPTIONS`` configuration
+        value in case it's set, otherwise a sensible default is returned.
+
+        .. versionadded:: 0.7
+        """
+        rv = self.config["PROPAGATE_EXCEPTIONS"]
+        if rv is not None:
+            return rv
+        return self.testing or self.debug
+
+    @property
+    def preserve_context_on_exception(self) -> bool:
+        """Returns the value of the ``PRESERVE_CONTEXT_ON_EXCEPTION``
+        configuration value in case it's set, otherwise a sensible default
+        is returned.
+
+        .. versionadded:: 0.7
+        """
+        rv = self.config["PRESERVE_CONTEXT_ON_EXCEPTION"]
+        if rv is not None:
+            return rv
+        return self.debug
+
+    @locked_cached_property
+    def logger(self) -> logging.Logger:
+        """A standard Python :class:`~logging.Logger` for the app, with
+        the same name as :attr:`name`.
+
+        In debug mode, the logger's :attr:`~logging.Logger.level` will
+        be set to :data:`~logging.DEBUG`.
+
+        If there are no handlers configured, a default handler will be
+        added. See :doc:`/logging` for more information.
+
+        .. versionchanged:: 1.1.0
+            The logger takes the same name as :attr:`name` rather than
+            hard-coding ``"flask.app"``.
+
+        .. versionchanged:: 1.0.0
+            Behavior was simplified. The logger is always named
+            ``"flask.app"``. The level is only set during configuration,
+            it doesn't check ``app.debug`` each time. Only one format is
+            used, not different ones depending on ``app.debug``. No
+            handlers are removed, and a handler is only added if no
+            handlers are already configured.
+
+        .. versionadded:: 0.3
+        """
+        return create_logger(self)
+
+    @locked_cached_property
+    def jinja_env(self) -> Environment:
+        """The Jinja environment used to load templates.
+
+        The environment is created the first time this property is
+        accessed. Changing :attr:`jinja_options` after that will have no
+        effect.
+        """
+        return self.create_jinja_environment()
+
+    @property
+    def got_first_request(self) -> bool:
+        """This attribute is set to ``True`` if the application started
+        handling the first request.
+
+        .. versionadded:: 0.8
+        """
+        return self._got_first_request
+
+    def make_config(self, instance_relative: bool = False) -> Config:
+        """Used to create the config attribute by the Flask constructor.
+        The `instance_relative` parameter is passed in from the constructor
+        of Flask (there named `instance_relative_config`) and indicates if
+        the config should be relative to the instance path or the root path
+        of the application.
+
+        .. versionadded:: 0.8
+        """
+        root_path = self.root_path
+        if instance_relative:
+            root_path = self.instance_path
+        defaults = dict(self.default_config)
+        defaults["ENV"] = get_env()
+        defaults["DEBUG"] = get_debug_flag()
+        return self.config_class(root_path, defaults)
+
+    def auto_find_instance_path(self) -> str:
+        """Tries to locate the instance path if it was not provided to the
+        constructor of the application class.  It will basically calculate
+        the path to a folder named ``instance`` next to your main file or
+        the package.
+
+        .. versionadded:: 0.8
+        """
+        prefix, package_path = find_package(self.import_name)
+        if prefix is None:
+            return os.path.join(package_path, "instance")
+        return os.path.join(prefix, "var", f"{self.name}-instance")
+
+    def open_instance_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
+        """Opens a resource from the application's instance folder
+        (:attr:`instance_path`).  Otherwise works like
+        :meth:`open_resource`.  Instance resources can also be opened for
+        writing.
+
+        :param resource: the name of the resource.  To access resources within
+                         subfolders use forward slashes as separator.
+        :param mode: resource file opening mode, default is 'rb'.
+        """
+        return open(os.path.join(self.instance_path, resource), mode)
+
+    @property
+    def templates_auto_reload(self) -> bool:
+        """Reload templates when they are changed. Used by
+        :meth:`create_jinja_environment`.
+
+        This attribute can be configured with :data:`TEMPLATES_AUTO_RELOAD`. If
+        not set, it will be enabled in debug mode.
+
+        .. versionadded:: 1.0
+            This property was added but the underlying config and behavior
+            already existed.
+        """
+        rv = self.config["TEMPLATES_AUTO_RELOAD"]
+        return rv if rv is not None else self.debug
+
+    @templates_auto_reload.setter
+    def templates_auto_reload(self, value: bool) -> None:
+        self.config["TEMPLATES_AUTO_RELOAD"] = value
+
+    def create_jinja_environment(self) -> Environment:
+        """Create the Jinja environment based on :attr:`jinja_options`
+        and the various Jinja-related methods of the app. Changing
+        :attr:`jinja_options` after this will have no effect. Also adds
+        Flask-related globals and filters to the environment.
+
+        .. versionchanged:: 0.11
+           ``Environment.auto_reload`` set in accordance with
+           ``TEMPLATES_AUTO_RELOAD`` configuration option.
+
+        .. versionadded:: 0.5
+        """
+        options = dict(self.jinja_options)
+
+        if "autoescape" not in options:
+            options["autoescape"] = self.select_jinja_autoescape
+
+        if "auto_reload" not in options:
+            options["auto_reload"] = self.templates_auto_reload
+
+        rv = self.jinja_environment(self, **options)
+        rv.globals.update(
+            url_for=url_for,
+            get_flashed_messages=get_flashed_messages,
+            config=self.config,
+            # request, session and g are normally added with the
+            # context processor for efficiency reasons but for imported
+            # templates we also want the proxies in there.
+            request=request,
+            session=session,
+            g=g,
+        )
+        rv.policies["json.dumps_function"] = json.dumps
+        return rv
+
+    def create_global_jinja_loader(self) -> DispatchingJinjaLoader:
+        """Creates the loader for the Jinja2 environment.  Can be used to
+        override just the loader and keeping the rest unchanged.  It's
+        discouraged to override this function.  Instead one should override
+        the :meth:`jinja_loader` function instead.
+
+        The global loader dispatches between the loaders of the application
+        and the individual blueprints.
+
+        .. versionadded:: 0.7
+        """
+        return DispatchingJinjaLoader(self)
+
+    def select_jinja_autoescape(self, filename: str) -> bool:
+        """Returns ``True`` if autoescaping should be active for the given
+        template name. If no template name is given, returns `True`.
+
+        .. versionadded:: 0.5
+        """
+        if filename is None:
+            return True
+        return filename.endswith((".html", ".htm", ".xml", ".xhtml"))
+
+    def update_template_context(self, context: dict) -> None:
+        """Update the template context with some commonly used variables.
+        This injects request, session, config and g into the template
+        context as well as everything template context processors want
+        to inject.  Note that the as of Flask 0.6, the original values
+        in the context will not be overridden if a context processor
+        decides to return a value with the same key.
+
+        :param context: the context as a dictionary that is updated in place
+                        to add extra variables.
+        """
+        names: t.Iterable[t.Optional[str]] = (None,)
+
+        # A template may be rendered outside a request context.
+        if request:
+            names = chain(names, reversed(request.blueprints))
+
+        # The values passed to render_template take precedence. Keep a
+        # copy to re-apply after all context functions.
+        orig_ctx = context.copy()
+
+        for name in names:
+            if name in self.template_context_processors:
+                for func in self.template_context_processors[name]:
+                    context.update(func())
+
+        context.update(orig_ctx)
+
+    def make_shell_context(self) -> dict:
+        """Returns the shell context for an interactive shell for this
+        application.  This runs all the registered shell context
+        processors.
+
+        .. versionadded:: 0.11
+        """
+        rv = {"app": self, "g": g}
+        for processor in self.shell_context_processors:
+            rv.update(processor())
+        return rv
+
+    #: What environment the app is running in. Flask and extensions may
+    #: enable behaviors based on the environment, such as enabling debug
+    #: mode. This maps to the :data:`ENV` config key. This is set by the
+    #: :envvar:`FLASK_ENV` environment variable and may not behave as
+    #: expected if set in code.
+    #:
+    #: **Do not enable development when deploying in production.**
+    #:
+    #: Default: ``'production'``
+    env = ConfigAttribute("ENV")
+
+    @property
+    def debug(self) -> bool:
+        """Whether debug mode is enabled. When using ``flask run`` to start
+        the development server, an interactive debugger will be shown for
+        unhandled exceptions, and the server will be reloaded when code
+        changes. This maps to the :data:`DEBUG` config key. This is
+        enabled when :attr:`env` is ``'development'`` and is overridden
+        by the ``FLASK_DEBUG`` environment variable. It may not behave as
+        expected if set in code.
+
+        **Do not enable debug mode when deploying in production.**
+
+        Default: ``True`` if :attr:`env` is ``'development'``, or
+        ``False`` otherwise.
+        """
+        return self.config["DEBUG"]
+
+    @debug.setter
+    def debug(self, value: bool) -> None:
+        self.config["DEBUG"] = value
+        self.jinja_env.auto_reload = self.templates_auto_reload
+
+    def run(
+        self,
+        host: t.Optional[str] = None,
+        port: t.Optional[int] = None,
+        debug: t.Optional[bool] = None,
+        load_dotenv: bool = True,
+        **options: t.Any,
+    ) -> None:
+        """Runs the application on a local development server.
+
+        Do not use ``run()`` in a production setting. It is not intended to
+        meet security and performance requirements for a production server.
+        Instead, see :doc:`/deploying/index` for WSGI server recommendations.
+
+        If the :attr:`debug` flag is set the server will automatically reload
+        for code changes and show a debugger in case an exception happened.
+
+        If you want to run the application in debug mode, but disable the
+        code execution on the interactive debugger, you can pass
+        ``use_evalex=False`` as parameter.  This will keep the debugger's
+        traceback screen active, but disable code execution.
+
+        It is not recommended to use this function for development with
+        automatic reloading as this is badly supported.  Instead you should
+        be using the :command:`flask` command line script's ``run`` support.
+
+        .. admonition:: Keep in Mind
+
+           Flask will suppress any server error with a generic error page
+           unless it is in debug mode.  As such to enable just the
+           interactive debugger without the code reloading, you have to
+           invoke :meth:`run` with ``debug=True`` and ``use_reloader=False``.
+           Setting ``use_debugger`` to ``True`` without being in debug mode
+           won't catch any exceptions because there won't be any to
+           catch.
+
+        :param host: the hostname to listen on. Set this to ``'0.0.0.0'`` to
+            have the server available externally as well. Defaults to
+            ``'127.0.0.1'`` or the host in the ``SERVER_NAME`` config variable
+            if present.
+        :param port: the port of the webserver. Defaults to ``5000`` or the
+            port defined in the ``SERVER_NAME`` config variable if present.
+        :param debug: if given, enable or disable debug mode. See
+            :attr:`debug`.
+        :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
+            files to set environment variables. Will also change the working
+            directory to the directory containing the first file found.
+        :param options: the options to be forwarded to the underlying Werkzeug
+            server. See :func:`werkzeug.serving.run_simple` for more
+            information.
+
+        .. versionchanged:: 1.0
+            If installed, python-dotenv will be used to load environment
+            variables from :file:`.env` and :file:`.flaskenv` files.
+
+            If set, the :envvar:`FLASK_ENV` and :envvar:`FLASK_DEBUG`
+            environment variables will override :attr:`env` and
+            :attr:`debug`.
+
+            Threaded mode is enabled by default.
+
+        .. versionchanged:: 0.10
+            The default port is now picked from the ``SERVER_NAME``
+            variable.
+        """
+        # Change this into a no-op if the server is invoked from the
+        # command line. Have a look at cli.py for more information.
+        if os.environ.get("FLASK_RUN_FROM_CLI") == "true":
+            from .debughelpers import explain_ignored_app_run
+
+            explain_ignored_app_run()
+            return
+
+        if get_load_dotenv(load_dotenv):
+            cli.load_dotenv()
+
+            # if set, let env vars override previous values
+            if "FLASK_ENV" in os.environ:
+                self.env = get_env()
+                self.debug = get_debug_flag()
+            elif "FLASK_DEBUG" in os.environ:
+                self.debug = get_debug_flag()
+
+        # debug passed to method overrides all other sources
+        if debug is not None:
+            self.debug = bool(debug)
+
+        server_name = self.config.get("SERVER_NAME")
+        sn_host = sn_port = None
+
+        if server_name:
+            sn_host, _, sn_port = server_name.partition(":")
+
+        if not host:
+            if sn_host:
+                host = sn_host
+            else:
+                host = "127.0.0.1"
+
+        if port or port == 0:
+            port = int(port)
+        elif sn_port:
+            port = int(sn_port)
+        else:
+            port = 5000
+
+        options.setdefault("use_reloader", self.debug)
+        options.setdefault("use_debugger", self.debug)
+        options.setdefault("threaded", True)
+
+        cli.show_server_banner(self.env, self.debug, self.name, False)
+
+        from werkzeug.serving import run_simple
+
+        try:
+            run_simple(t.cast(str, host), port, self, **options)
+        finally:
+            # reset the first request information if the development server
+            # reset normally.  This makes it possible to restart the server
+            # without reloader and that stuff from an interactive shell.
+            self._got_first_request = False
+
+    def test_client(self, use_cookies: bool = True, **kwargs: t.Any) -> "FlaskClient":
+        """Creates a test client for this application.  For information
+        about unit testing head over to :doc:`/testing`.
+
+        Note that if you are testing for assertions or exceptions in your
+        application code, you must set ``app.testing = True`` in order for the
+        exceptions to propagate to the test client.  Otherwise, the exception
+        will be handled by the application (not visible to the test client) and
+        the only indication of an AssertionError or other exception will be a
+        500 status code response to the test client.  See the :attr:`testing`
+        attribute.  For example::
+
+            app.testing = True
+            client = app.test_client()
+
+        The test client can be used in a ``with`` block to defer the closing down
+        of the context until the end of the ``with`` block.  This is useful if
+        you want to access the context locals for testing::
+
+            with app.test_client() as c:
+                rv = c.get('/?vodka=42')
+                assert request.args['vodka'] == '42'
+
+        Additionally, you may pass optional keyword arguments that will then
+        be passed to the application's :attr:`test_client_class` constructor.
+        For example::
+
+            from flask.testing import FlaskClient
+
+            class CustomClient(FlaskClient):
+                def __init__(self, *args, **kwargs):
+                    self._authentication = kwargs.pop("authentication")
+                    super(CustomClient,self).__init__( *args, **kwargs)
+
+            app.test_client_class = CustomClient
+            client = app.test_client(authentication='Basic ....')
+
+        See :class:`~flask.testing.FlaskClient` for more information.
+
+        .. versionchanged:: 0.4
+           added support for ``with`` block usage for the client.
+
+        .. versionadded:: 0.7
+           The `use_cookies` parameter was added as well as the ability
+           to override the client to be used by setting the
+           :attr:`test_client_class` attribute.
+
+        .. versionchanged:: 0.11
+           Added `**kwargs` to support passing additional keyword arguments to
+           the constructor of :attr:`test_client_class`.
+        """
+        cls = self.test_client_class
+        if cls is None:
+            from .testing import FlaskClient as cls  # type: ignore
+        return cls(  # type: ignore
+            self, self.response_class, use_cookies=use_cookies, **kwargs
+        )
+
+    def test_cli_runner(self, **kwargs: t.Any) -> "FlaskCliRunner":
+        """Create a CLI runner for testing CLI commands.
+        See :ref:`testing-cli`.
+
+        Returns an instance of :attr:`test_cli_runner_class`, by default
+        :class:`~flask.testing.FlaskCliRunner`. The Flask app object is
+        passed as the first argument.
+
+        .. versionadded:: 1.0
+        """
+        cls = self.test_cli_runner_class
+
+        if cls is None:
+            from .testing import FlaskCliRunner as cls  # type: ignore
+
+        return cls(self, **kwargs)  # type: ignore
+
+    @setupmethod
+    def register_blueprint(self, blueprint: "Blueprint", **options: t.Any) -> None:
+        """Register a :class:`~flask.Blueprint` on the application. Keyword
+        arguments passed to this method will override the defaults set on the
+        blueprint.
+
+        Calls the blueprint's :meth:`~flask.Blueprint.register` method after
+        recording the blueprint in the application's :attr:`blueprints`.
+
+        :param blueprint: The blueprint to register.
+        :param url_prefix: Blueprint routes will be prefixed with this.
+        :param subdomain: Blueprint routes will match on this subdomain.
+        :param url_defaults: Blueprint routes will use these default values for
+            view arguments.
+        :param options: Additional keyword arguments are passed to
+            :class:`~flask.blueprints.BlueprintSetupState`. They can be
+            accessed in :meth:`~flask.Blueprint.record` callbacks.
+
+        .. versionchanged:: 2.0.1
+            The ``name`` option can be used to change the (pre-dotted)
+            name the blueprint is registered with. This allows the same
+            blueprint to be registered multiple times with unique names
+            for ``url_for``.
+
+        .. versionadded:: 0.7
+        """
+        blueprint.register(self, options)
+
+    def iter_blueprints(self) -> t.ValuesView["Blueprint"]:
+        """Iterates over all blueprints by the order they were registered.
+
+        .. versionadded:: 0.11
+        """
+        return self.blueprints.values()
+
+    @setupmethod
+    def add_url_rule(
+        self,
+        rule: str,
+        endpoint: t.Optional[str] = None,
+        view_func: t.Optional[t.Callable] = None,
+        provide_automatic_options: t.Optional[bool] = None,
+        **options: t.Any,
+    ) -> None:
+        if endpoint is None:
+            endpoint = _endpoint_from_view_func(view_func)  # type: ignore
+        options["endpoint"] = endpoint
+        methods = options.pop("methods", None)
+
+        # if the methods are not given and the view_func object knows its
+        # methods we can use that instead.  If neither exists, we go with
+        # a tuple of only ``GET`` as default.
+        if methods is None:
+            methods = getattr(view_func, "methods", None) or ("GET",)
+        if isinstance(methods, str):
+            raise TypeError(
+                "Allowed methods must be a list of strings, for"
+                ' example: @app.route(..., methods=["POST"])'
+            )
+        methods = {item.upper() for item in methods}
+
+        # Methods that should always be added
+        required_methods = set(getattr(view_func, "required_methods", ()))
+
+        # starting with Flask 0.8 the view_func object can disable and
+        # force-enable the automatic options handling.
+        if provide_automatic_options is None:
+            provide_automatic_options = getattr(
+                view_func, "provide_automatic_options", None
+            )
+
+        if provide_automatic_options is None:
+            if "OPTIONS" not in methods:
+                provide_automatic_options = True
+                required_methods.add("OPTIONS")
+            else:
+                provide_automatic_options = False
+
+        # Add the required methods now.
+        methods |= required_methods
+
+        rule = self.url_rule_class(rule, methods=methods, **options)
+        rule.provide_automatic_options = provide_automatic_options  # type: ignore
+
+        self.url_map.add(rule)
+        if view_func is not None:
+            old_func = self.view_functions.get(endpoint)
+            if old_func is not None and old_func != view_func:
+                raise AssertionError(
+                    "View function mapping is overwriting an existing"
+                    f" endpoint function: {endpoint}"
+                )
+            self.view_functions[endpoint] = view_func
+
+    @setupmethod
+    def template_filter(
+        self, name: t.Optional[str] = None
+    ) -> t.Callable[[TemplateFilterCallable], TemplateFilterCallable]:
+        """A decorator that is used to register custom template filter.
+        You can specify a name for the filter, otherwise the function
+        name will be used. Example::
+
+          @app.template_filter()
+          def reverse(s):
+              return s[::-1]
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+
+        def decorator(f: TemplateFilterCallable) -> TemplateFilterCallable:
+            self.add_template_filter(f, name=name)
+            return f
+
+        return decorator
+
+    @setupmethod
+    def add_template_filter(
+        self, f: TemplateFilterCallable, name: t.Optional[str] = None
+    ) -> None:
+        """Register a custom template filter.  Works exactly like the
+        :meth:`template_filter` decorator.
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.filters[name or f.__name__] = f
+
+    @setupmethod
+    def template_test(
+        self, name: t.Optional[str] = None
+    ) -> t.Callable[[TemplateTestCallable], TemplateTestCallable]:
+        """A decorator that is used to register custom template test.
+        You can specify a name for the test, otherwise the function
+        name will be used. Example::
+
+          @app.template_test()
+          def is_prime(n):
+              if n == 2:
+                  return True
+              for i in range(2, int(math.ceil(math.sqrt(n))) + 1):
+                  if n % i == 0:
+                      return False
+              return True
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+
+        def decorator(f: TemplateTestCallable) -> TemplateTestCallable:
+            self.add_template_test(f, name=name)
+            return f
+
+        return decorator
+
+    @setupmethod
+    def add_template_test(
+        self, f: TemplateTestCallable, name: t.Optional[str] = None
+    ) -> None:
+        """Register a custom template test.  Works exactly like the
+        :meth:`template_test` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.tests[name or f.__name__] = f
+
+    @setupmethod
+    def template_global(
+        self, name: t.Optional[str] = None
+    ) -> t.Callable[[TemplateGlobalCallable], TemplateGlobalCallable]:
+        """A decorator that is used to register a custom template global function.
+        You can specify a name for the global function, otherwise the function
+        name will be used. Example::
+
+            @app.template_global()
+            def double(n):
+                return 2 * n
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global function, otherwise the
+                     function name will be used.
+        """
+
+        def decorator(f: TemplateGlobalCallable) -> TemplateGlobalCallable:
+            self.add_template_global(f, name=name)
+            return f
+
+        return decorator
+
+    @setupmethod
+    def add_template_global(
+        self, f: TemplateGlobalCallable, name: t.Optional[str] = None
+    ) -> None:
+        """Register a custom template global function. Works exactly like the
+        :meth:`template_global` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global function, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.globals[name or f.__name__] = f
+
+    @setupmethod
+    def before_first_request(
+        self, f: BeforeFirstRequestCallable
+    ) -> BeforeFirstRequestCallable:
+        """Registers a function to be run before the first request to this
+        instance of the application.
+
+        The function will be called without any arguments and its return
+        value is ignored.
+
+        .. versionadded:: 0.8
+        """
+        self.before_first_request_funcs.append(f)
+        return f
+
+    @setupmethod
+    def teardown_appcontext(self, f: TeardownCallable) -> TeardownCallable:
+        """Registers a function to be called when the application context
+        ends.  These functions are typically also called when the request
+        context is popped.
+
+        Example::
+
+            ctx = app.app_context()
+            ctx.push()
+            ...
+            ctx.pop()
+
+        When ``ctx.pop()`` is executed in the above example, the teardown
+        functions are called just before the app context moves from the
+        stack of active contexts.  This becomes relevant if you are using
+        such constructs in tests.
+
+        Since a request context typically also manages an application
+        context it would also be called when you pop a request context.
+
+        When a teardown function was called because of an unhandled exception
+        it will be passed an error object. If an :meth:`errorhandler` is
+        registered, it will handle the exception and the teardown will not
+        receive it.
+
+        The return values of teardown functions are ignored.
+
+        .. versionadded:: 0.9
+        """
+        self.teardown_appcontext_funcs.append(f)
+        return f
+
+    @setupmethod
+    def shell_context_processor(self, f: t.Callable) -> t.Callable:
+        """Registers a shell context processor function.
+
+        .. versionadded:: 0.11
+        """
+        self.shell_context_processors.append(f)
+        return f
+
+    def _find_error_handler(
+        self, e: Exception
+    ) -> t.Optional["ErrorHandlerCallable[Exception]"]:
+        """Return a registered error handler for an exception in this order:
+        blueprint handler for a specific code, app handler for a specific code,
+        blueprint handler for an exception class, app handler for an exception
+        class, or ``None`` if a suitable handler is not found.
+        """
+        exc_class, code = self._get_exc_class_and_code(type(e))
+        names = (*request.blueprints, None)
+
+        for c in (code, None) if code is not None else (None,):
+            for name in names:
+                handler_map = self.error_handler_spec[name][c]
+
+                if not handler_map:
+                    continue
+
+                for cls in exc_class.__mro__:
+                    handler = handler_map.get(cls)
+
+                    if handler is not None:
+                        return handler
+        return None
+
+    def handle_http_exception(
+        self, e: HTTPException
+    ) -> t.Union[HTTPException, ResponseReturnValue]:
+        """Handles an HTTP exception.  By default this will invoke the
+        registered error handlers and fall back to returning the
+        exception as response.
+
+        .. versionchanged:: 1.0.3
+            ``RoutingException``, used internally for actions such as
+             slash redirects during routing, is not passed to error
+             handlers.
+
+        .. versionchanged:: 1.0
+            Exceptions are looked up by code *and* by MRO, so
+            ``HTTPException`` subclasses can be handled with a catch-all
+            handler for the base ``HTTPException``.
+
+        .. versionadded:: 0.3
+        """
+        # Proxy exceptions don't have error codes.  We want to always return
+        # those unchanged as errors
+        if e.code is None:
+            return e
+
+        # RoutingExceptions are used internally to trigger routing
+        # actions, such as slash redirects raising RequestRedirect. They
+        # are not raised or handled in user code.
+        if isinstance(e, RoutingException):
+            return e
+
+        handler = self._find_error_handler(e)
+        if handler is None:
+            return e
+        return self.ensure_sync(handler)(e)
+
+    def trap_http_exception(self, e: Exception) -> bool:
+        """Checks if an HTTP exception should be trapped or not.  By default
+        this will return ``False`` for all exceptions except for a bad request
+        key error if ``TRAP_BAD_REQUEST_ERRORS`` is set to ``True``.  It
+        also returns ``True`` if ``TRAP_HTTP_EXCEPTIONS`` is set to ``True``.
+
+        This is called for all HTTP exceptions raised by a view function.
+        If it returns ``True`` for any exception the error handler for this
+        exception is not called and it shows up as regular exception in the
+        traceback.  This is helpful for debugging implicitly raised HTTP
+        exceptions.
+
+        .. versionchanged:: 1.0
+            Bad request errors are not trapped by default in debug mode.
+
+        .. versionadded:: 0.8
+        """
+        if self.config["TRAP_HTTP_EXCEPTIONS"]:
+            return True
+
+        trap_bad_request = self.config["TRAP_BAD_REQUEST_ERRORS"]
+
+        # if unset, trap key errors in debug mode
+        if (
+            trap_bad_request is None
+            and self.debug
+            and isinstance(e, BadRequestKeyError)
+        ):
+            return True
+
+        if trap_bad_request:
+            return isinstance(e, BadRequest)
+
+        return False
+
+    def handle_user_exception(
+        self, e: Exception
+    ) -> t.Union[HTTPException, ResponseReturnValue]:
+        """This method is called whenever an exception occurs that
+        should be handled. A special case is :class:`~werkzeug
+        .exceptions.HTTPException` which is forwarded to the
+        :meth:`handle_http_exception` method. This function will either
+        return a response value or reraise the exception with the same
+        traceback.
+
+        .. versionchanged:: 1.0
+            Key errors raised from request data like ``form`` show the
+            bad key in debug mode rather than a generic bad request
+            message.
+
+        .. versionadded:: 0.7
+        """
+        if isinstance(e, BadRequestKeyError) and (
+            self.debug or self.config["TRAP_BAD_REQUEST_ERRORS"]
+        ):
+            e.show_exception = True
+
+        if isinstance(e, HTTPException) and not self.trap_http_exception(e):
+            return self.handle_http_exception(e)
+
+        handler = self._find_error_handler(e)
+
+        if handler is None:
+            raise
+
+        return self.ensure_sync(handler)(e)
+
+    def handle_exception(self, e: Exception) -> Response:
+        """Handle an exception that did not have an error handler
+        associated with it, or that was raised from an error handler.
+        This always causes a 500 ``InternalServerError``.
+
+        Always sends the :data:`got_request_exception` signal.
+
+        If :attr:`propagate_exceptions` is ``True``, such as in debug
+        mode, the error will be re-raised so that the debugger can
+        display it. Otherwise, the original exception is logged, and
+        an :exc:`~werkzeug.exceptions.InternalServerError` is returned.
+
+        If an error handler is registered for ``InternalServerError`` or
+        ``500``, it will be used. For consistency, the handler will
+        always receive the ``InternalServerError``. The original
+        unhandled exception is available as ``e.original_exception``.
+
+        .. versionchanged:: 1.1.0
+            Always passes the ``InternalServerError`` instance to the
+            handler, setting ``original_exception`` to the unhandled
+            error.
+
+        .. versionchanged:: 1.1.0
+            ``after_request`` functions and other finalization is done
+            even for the default 500 response when there is no handler.
+
+        .. versionadded:: 0.3
+        """
+        exc_info = sys.exc_info()
+        got_request_exception.send(self, exception=e)
+
+        if self.propagate_exceptions:
+            # Re-raise if called with an active exception, otherwise
+            # raise the passed in exception.
+            if exc_info[1] is e:
+                raise
+
+            raise e
+
+        self.log_exception(exc_info)
+        server_error: t.Union[InternalServerError, ResponseReturnValue]
+        server_error = InternalServerError(original_exception=e)
+        handler = self._find_error_handler(server_error)
+
+        if handler is not None:
+            server_error = self.ensure_sync(handler)(server_error)
+
+        return self.finalize_request(server_error, from_error_handler=True)
+
+    def log_exception(
+        self,
+        exc_info: t.Union[
+            t.Tuple[type, BaseException, TracebackType], t.Tuple[None, None, None]
+        ],
+    ) -> None:
+        """Logs an exception.  This is called by :meth:`handle_exception`
+        if debugging is disabled and right before the handler is called.
+        The default implementation logs the exception as error on the
+        :attr:`logger`.
+
+        .. versionadded:: 0.8
+        """
+        self.logger.error(
+            f"Exception on {request.path} [{request.method}]", exc_info=exc_info
+        )
+
+    def raise_routing_exception(self, request: Request) -> "te.NoReturn":
+        """Exceptions that are recording during routing are reraised with
+        this method.  During debug we are not reraising redirect requests
+        for non ``GET``, ``HEAD``, or ``OPTIONS`` requests and we're raising
+        a different error instead to help debug situations.
+
+        :internal:
+        """
+        if (
+            not self.debug
+            or not isinstance(request.routing_exception, RequestRedirect)
+            or request.method in ("GET", "HEAD", "OPTIONS")
+        ):
+            raise request.routing_exception  # type: ignore
+
+        from .debughelpers import FormDataRoutingRedirect
+
+        raise FormDataRoutingRedirect(request)
+
+    def dispatch_request(self) -> ResponseReturnValue:
+        """Does the request dispatching.  Matches the URL and returns the
+        return value of the view or error handler.  This does not have to
+        be a response object.  In order to convert the return value to a
+        proper response object, call :func:`make_response`.
+
+        .. versionchanged:: 0.7
+           This no longer does the exception handling, this code was
+           moved to the new :meth:`full_dispatch_request`.
+        """
+        req = _request_ctx_stack.top.request
+        if req.routing_exception is not None:
+            self.raise_routing_exception(req)
+        rule = req.url_rule
+        # if we provide automatic options for this URL and the
+        # request came with the OPTIONS method, reply automatically
+        if (
+            getattr(rule, "provide_automatic_options", False)
+            and req.method == "OPTIONS"
+        ):
+            return self.make_default_options_response()
+        # otherwise dispatch to the handler for that endpoint
+        return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
+
+    def full_dispatch_request(self) -> Response:
+        """Dispatches the request and on top of that performs request
+        pre and postprocessing as well as HTTP exception catching and
+        error handling.
+
+        .. versionadded:: 0.7
+        """
+        self.try_trigger_before_first_request_functions()
+        try:
+            request_started.send(self)
+            rv = self.preprocess_request()
+            if rv is None:
+                rv = self.dispatch_request()
+        except Exception as e:
+            rv = self.handle_user_exception(e)
+        return self.finalize_request(rv)
+
+    def finalize_request(
+        self,
+        rv: t.Union[ResponseReturnValue, HTTPException],
+        from_error_handler: bool = False,
+    ) -> Response:
+        """Given the return value from a view function this finalizes
+        the request by converting it into a response and invoking the
+        postprocessing functions.  This is invoked for both normal
+        request dispatching as well as error handlers.
+
+        Because this means that it might be called as a result of a
+        failure a special safe mode is available which can be enabled
+        with the `from_error_handler` flag.  If enabled, failures in
+        response processing will be logged and otherwise ignored.
+
+        :internal:
+        """
+        response = self.make_response(rv)
+        try:
+            response = self.process_response(response)
+            request_finished.send(self, response=response)
+        except Exception:
+            if not from_error_handler:
+                raise
+            self.logger.exception(
+                "Request finalizing failed with an error while handling an error"
+            )
+        return response
+
+    def try_trigger_before_first_request_functions(self) -> None:
+        """Called before each request and will ensure that it triggers
+        the :attr:`before_first_request_funcs` and only exactly once per
+        application instance (which means process usually).
+
+        :internal:
+        """
+        if self._got_first_request:
+            return
+        with self._before_request_lock:
+            if self._got_first_request:
+                return
+            for func in self.before_first_request_funcs:
+                self.ensure_sync(func)()
+            self._got_first_request = True
+
+    def make_default_options_response(self) -> Response:
+        """This method is called to create the default ``OPTIONS`` response.
+        This can be changed through subclassing to change the default
+        behavior of ``OPTIONS`` responses.
+
+        .. versionadded:: 0.7
+        """
+        adapter = _request_ctx_stack.top.url_adapter
+        methods = adapter.allowed_methods()
+        rv = self.response_class()
+        rv.allow.update(methods)
+        return rv
+
+    def should_ignore_error(self, error: t.Optional[BaseException]) -> bool:
+        """This is called to figure out if an error should be ignored
+        or not as far as the teardown system is concerned.  If this
+        function returns ``True`` then the teardown handlers will not be
+        passed the error.
+
+        .. versionadded:: 0.10
+        """
+        return False
+
+    def ensure_sync(self, func: t.Callable) -> t.Callable:
+        """Ensure that the function is synchronous for WSGI workers.
+        Plain ``def`` functions are returned as-is. ``async def``
+        functions are wrapped to run and wait for the response.
+
+        Override this method to change how the app runs async views.
+
+        .. versionadded:: 2.0
+        """
+        if iscoroutinefunction(func):
+            return self.async_to_sync(func)
+
+        return func
+
+    def async_to_sync(
+        self, func: t.Callable[..., t.Coroutine]
+    ) -> t.Callable[..., t.Any]:
+        """Return a sync function that will run the coroutine function.
+
+        .. code-block:: python
+
+            result = app.async_to_sync(func)(*args, **kwargs)
+
+        Override this method to change how the app converts async code
+        to be synchronously callable.
+
+        .. versionadded:: 2.0
+        """
+        try:
+            from asgiref.sync import async_to_sync as asgiref_async_to_sync
+        except ImportError:
+            raise RuntimeError(
+                "Install Flask with the 'async' extra in order to use async views."
+            ) from None
+
+        # Check that Werkzeug isn't using its fallback ContextVar class.
+        if ContextVar.__module__ == "werkzeug.local":
+            raise RuntimeError(
+                "Async cannot be used with this combination of Python "
+                "and Greenlet versions."
+            )
+
+        return asgiref_async_to_sync(func)
+
+    def make_response(self, rv: ResponseReturnValue) -> Response:
+        """Convert the return value from a view function to an instance of
+        :attr:`response_class`.
+
+        :param rv: the return value from the view function. The view function
+            must return a response. Returning ``None``, or the view ending
+            without returning, is not allowed. The following types are allowed
+            for ``view_rv``:
+
+            ``str``
+                A response object is created with the string encoded to UTF-8
+                as the body.
+
+            ``bytes``
+                A response object is created with the bytes as the body.
+
+            ``dict``
+                A dictionary that will be jsonify'd before being returned.
+
+            ``tuple``
+                Either ``(body, status, headers)``, ``(body, status)``, or
+                ``(body, headers)``, where ``body`` is any of the other types
+                allowed here, ``status`` is a string or an integer, and
+                ``headers`` is a dictionary or a list of ``(key, value)``
+                tuples. If ``body`` is a :attr:`response_class` instance,
+                ``status`` overwrites the exiting value and ``headers`` are
+                extended.
+
+            :attr:`response_class`
+                The object is returned unchanged.
+
+            other :class:`~werkzeug.wrappers.Response` class
+                The object is coerced to :attr:`response_class`.
+
+            :func:`callable`
+                The function is called as a WSGI application. The result is
+                used to create a response object.
+
+        .. versionchanged:: 0.9
+           Previously a tuple was interpreted as the arguments for the
+           response object.
+        """
+
+        status = headers = None
+
+        # unpack tuple returns
+        if isinstance(rv, tuple):
+            len_rv = len(rv)
+
+            # a 3-tuple is unpacked directly
+            if len_rv == 3:
+                rv, status, headers = rv
+            # decide if a 2-tuple has status or headers
+            elif len_rv == 2:
+                if isinstance(rv[1], (Headers, dict, tuple, list)):
+                    rv, headers = rv
+                else:
+                    rv, status = rv
+            # other sized tuples are not allowed
+            else:
+                raise TypeError(
+                    "The view function did not return a valid response tuple."
+                    " The tuple must have the form (body, status, headers),"
+                    " (body, status), or (body, headers)."
+                )
+
+        # the body must not be None
+        if rv is None:
+            raise TypeError(
+                f"The view function for {request.endpoint!r} did not"
+                " return a valid response. The function either returned"
+                " None or ended without a return statement."
+            )
+
+        # make sure the body is an instance of the response class
+        if not isinstance(rv, self.response_class):
+            if isinstance(rv, (str, bytes, bytearray)):
+                # let the response class set the status and headers instead of
+                # waiting to do it manually, so that the class can handle any
+                # special logic
+                rv = self.response_class(rv, status=status, headers=headers)
+                status = headers = None
+            elif isinstance(rv, dict):
+                rv = jsonify(rv)
+            elif isinstance(rv, BaseResponse) or callable(rv):
+                # evaluate a WSGI callable, or coerce a different response
+                # class to the correct type
+                try:
+                    rv = self.response_class.force_type(rv, request.environ)  # type: ignore  # noqa: B950
+                except TypeError as e:
+                    raise TypeError(
+                        f"{e}\nThe view function did not return a valid"
+                        " response. The return type must be a string,"
+                        " dict, tuple, Response instance, or WSGI"
+                        f" callable, but it was a {type(rv).__name__}."
+                    ).with_traceback(sys.exc_info()[2]) from None
+            else:
+                raise TypeError(
+                    "The view function did not return a valid"
+                    " response. The return type must be a string,"
+                    " dict, tuple, Response instance, or WSGI"
+                    f" callable, but it was a {type(rv).__name__}."
+                )
+
+        rv = t.cast(Response, rv)
+        # prefer the status if it was provided
+        if status is not None:
+            if isinstance(status, (str, bytes, bytearray)):
+                rv.status = status  # type: ignore
+            else:
+                rv.status_code = status
+
+        # extend existing headers with provided headers
+        if headers:
+            rv.headers.update(headers)
+
+        return rv
+
+    def create_url_adapter(
+        self, request: t.Optional[Request]
+    ) -> t.Optional[MapAdapter]:
+        """Creates a URL adapter for the given request. The URL adapter
+        is created at a point where the request context is not yet set
+        up so the request is passed explicitly.
+
+        .. versionadded:: 0.6
+
+        .. versionchanged:: 0.9
+           This can now also be called without a request object when the
+           URL adapter is created for the application context.
+
+        .. versionchanged:: 1.0
+            :data:`SERVER_NAME` no longer implicitly enables subdomain
+            matching. Use :attr:`subdomain_matching` instead.
+        """
+        if request is not None:
+            # If subdomain matching is disabled (the default), use the
+            # default subdomain in all cases. This should be the default
+            # in Werkzeug but it currently does not have that feature.
+            if not self.subdomain_matching:
+                subdomain = self.url_map.default_subdomain or None
+            else:
+                subdomain = None
+
+            return self.url_map.bind_to_environ(
+                request.environ,
+                server_name=self.config["SERVER_NAME"],
+                subdomain=subdomain,
+            )
+        # We need at the very least the server name to be set for this
+        # to work.
+        if self.config["SERVER_NAME"] is not None:
+            return self.url_map.bind(
+                self.config["SERVER_NAME"],
+                script_name=self.config["APPLICATION_ROOT"],
+                url_scheme=self.config["PREFERRED_URL_SCHEME"],
+            )
+
+        return None
+
+    def inject_url_defaults(self, endpoint: str, values: dict) -> None:
+        """Injects the URL defaults for the given endpoint directly into
+        the values dictionary passed.  This is used internally and
+        automatically called on URL building.
+
+        .. versionadded:: 0.7
+        """
+        names: t.Iterable[t.Optional[str]] = (None,)
+
+        # url_for may be called outside a request context, parse the
+        # passed endpoint instead of using request.blueprints.
+        if "." in endpoint:
+            names = chain(
+                names, reversed(_split_blueprint_path(endpoint.rpartition(".")[0]))
+            )
+
+        for name in names:
+            if name in self.url_default_functions:
+                for func in self.url_default_functions[name]:
+                    func(endpoint, values)
+
+    def handle_url_build_error(
+        self, error: Exception, endpoint: str, values: dict
+    ) -> str:
+        """Handle :class:`~werkzeug.routing.BuildError` on
+        :meth:`url_for`.
+        """
+        for handler in self.url_build_error_handlers:
+            try:
+                rv = handler(error, endpoint, values)
+            except BuildError as e:
+                # make error available outside except block
+                error = e
+            else:
+                if rv is not None:
+                    return rv
+
+        # Re-raise if called with an active exception, otherwise raise
+        # the passed in exception.
+        if error is sys.exc_info()[1]:
+            raise
+
+        raise error
+
+    def preprocess_request(self) -> t.Optional[ResponseReturnValue]:
+        """Called before the request is dispatched. Calls
+        :attr:`url_value_preprocessors` registered with the app and the
+        current blueprint (if any). Then calls :attr:`before_request_funcs`
+        registered with the app and the blueprint.
+
+        If any :meth:`before_request` handler returns a non-None value, the
+        value is handled as if it was the return value from the view, and
+        further request handling is stopped.
+        """
+        names = (None, *reversed(request.blueprints))
+
+        for name in names:
+            if name in self.url_value_preprocessors:
+                for url_func in self.url_value_preprocessors[name]:
+                    url_func(request.endpoint, request.view_args)
+
+        for name in names:
+            if name in self.before_request_funcs:
+                for before_func in self.before_request_funcs[name]:
+                    rv = self.ensure_sync(before_func)()
+
+                    if rv is not None:
+                        return rv
+
+        return None
+
+    def process_response(self, response: Response) -> Response:
+        """Can be overridden in order to modify the response object
+        before it's sent to the WSGI server.  By default this will
+        call all the :meth:`after_request` decorated functions.
+
+        .. versionchanged:: 0.5
+           As of Flask 0.5 the functions registered for after request
+           execution are called in reverse order of registration.
+
+        :param response: a :attr:`response_class` object.
+        :return: a new response object or the same, has to be an
+                 instance of :attr:`response_class`.
+        """
+        ctx = _request_ctx_stack.top
+
+        for func in ctx._after_request_functions:
+            response = self.ensure_sync(func)(response)
+
+        for name in chain(request.blueprints, (None,)):
+            if name in self.after_request_funcs:
+                for func in reversed(self.after_request_funcs[name]):
+                    response = self.ensure_sync(func)(response)
+
+        if not self.session_interface.is_null_session(ctx.session):
+            self.session_interface.save_session(self, ctx.session, response)
+
+        return response
+
+    def do_teardown_request(
+        self, exc: t.Optional[BaseException] = _sentinel  # type: ignore
+    ) -> None:
+        """Called after the request is dispatched and the response is
+        returned, right before the request context is popped.
+
+        This calls all functions decorated with
+        :meth:`teardown_request`, and :meth:`Blueprint.teardown_request`
+        if a blueprint handled the request. Finally, the
+        :data:`request_tearing_down` signal is sent.
+
+        This is called by
+        :meth:`RequestContext.pop() <flask.ctx.RequestContext.pop>`,
+        which may be delayed during testing to maintain access to
+        resources.
+
+        :param exc: An unhandled exception raised while dispatching the
+            request. Detected from the current exception information if
+            not passed. Passed to each teardown function.
+
+        .. versionchanged:: 0.9
+            Added the ``exc`` argument.
+        """
+        if exc is _sentinel:
+            exc = sys.exc_info()[1]
+
+        for name in chain(request.blueprints, (None,)):
+            if name in self.teardown_request_funcs:
+                for func in reversed(self.teardown_request_funcs[name]):
+                    self.ensure_sync(func)(exc)
+
+        request_tearing_down.send(self, exc=exc)
+
+    def do_teardown_appcontext(
+        self, exc: t.Optional[BaseException] = _sentinel  # type: ignore
+    ) -> None:
+        """Called right before the application context is popped.
+
+        When handling a request, the application context is popped
+        after the request context. See :meth:`do_teardown_request`.
+
+        This calls all functions decorated with
+        :meth:`teardown_appcontext`. Then the
+        :data:`appcontext_tearing_down` signal is sent.
+
+        This is called by
+        :meth:`AppContext.pop() <flask.ctx.AppContext.pop>`.
+
+        .. versionadded:: 0.9
+        """
+        if exc is _sentinel:
+            exc = sys.exc_info()[1]
+
+        for func in reversed(self.teardown_appcontext_funcs):
+            self.ensure_sync(func)(exc)
+
+        appcontext_tearing_down.send(self, exc=exc)
+
+    def app_context(self) -> AppContext:
+        """Create an :class:`~flask.ctx.AppContext`. Use as a ``with``
+        block to push the context, which will make :data:`current_app`
+        point at this application.
+
+        An application context is automatically pushed by
+        :meth:`RequestContext.push() <flask.ctx.RequestContext.push>`
+        when handling a request, and when running a CLI command. Use
+        this to manually create a context outside of these situations.
+
+        ::
+
+            with app.app_context():
+                init_db()
+
+        See :doc:`/appcontext`.
+
+        .. versionadded:: 0.9
+        """
+        return AppContext(self)
+
+    def request_context(self, environ: dict) -> RequestContext:
+        """Create a :class:`~flask.ctx.RequestContext` representing a
+        WSGI environment. Use a ``with`` block to push the context,
+        which will make :data:`request` point at this request.
+
+        See :doc:`/reqcontext`.
+
+        Typically you should not call this from your own code. A request
+        context is automatically pushed by the :meth:`wsgi_app` when
+        handling a request. Use :meth:`test_request_context` to create
+        an environment and context instead of this method.
+
+        :param environ: a WSGI environment
+        """
+        return RequestContext(self, environ)
+
+    def test_request_context(self, *args: t.Any, **kwargs: t.Any) -> RequestContext:
+        """Create a :class:`~flask.ctx.RequestContext` for a WSGI
+        environment created from the given values. This is mostly useful
+        during testing, where you may want to run a function that uses
+        request data without dispatching a full request.
+
+        See :doc:`/reqcontext`.
+
+        Use a ``with`` block to push the context, which will make
+        :data:`request` point at the request for the created
+        environment. ::
+
+            with test_request_context(...):
+                generate_report()
+
+        When using the shell, it may be easier to push and pop the
+        context manually to avoid indentation. ::
+
+            ctx = app.test_request_context(...)
+            ctx.push()
+            ...
+            ctx.pop()
+
+        Takes the same arguments as Werkzeug's
+        :class:`~werkzeug.test.EnvironBuilder`, with some defaults from
+        the application. See the linked Werkzeug docs for most of the
+        available arguments. Flask-specific behavior is listed here.
+
+        :param path: URL path being requested.
+        :param base_url: Base URL where the app is being served, which
+            ``path`` is relative to. If not given, built from
+            :data:`PREFERRED_URL_SCHEME`, ``subdomain``,
+            :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`.
+        :param subdomain: Subdomain name to append to
+            :data:`SERVER_NAME`.
+        :param url_scheme: Scheme to use instead of
+            :data:`PREFERRED_URL_SCHEME`.
+        :param data: The request body, either as a string or a dict of
+            form keys and values.
+        :param json: If given, this is serialized as JSON and passed as
+            ``data``. Also defaults ``content_type`` to
+            ``application/json``.
+        :param args: other positional arguments passed to
+            :class:`~werkzeug.test.EnvironBuilder`.
+        :param kwargs: other keyword arguments passed to
+            :class:`~werkzeug.test.EnvironBuilder`.
+        """
+        from .testing import EnvironBuilder
+
+        builder = EnvironBuilder(self, *args, **kwargs)
+
+        try:
+            return self.request_context(builder.get_environ())
+        finally:
+            builder.close()
+
+    def wsgi_app(self, environ: dict, start_response: t.Callable) -> t.Any:
+        """The actual WSGI application. This is not implemented in
+        :meth:`__call__` so that middlewares can be applied without
+        losing a reference to the app object. Instead of doing this::
+
+            app = MyMiddleware(app)
+
+        It's a better idea to do this instead::
+
+            app.wsgi_app = MyMiddleware(app.wsgi_app)
+
+        Then you still have the original application object around and
+        can continue to call methods on it.
+
+        .. versionchanged:: 0.7
+            Teardown events for the request and app contexts are called
+            even if an unhandled error occurs. Other events may not be
+            called depending on when an error occurs during dispatch.
+            See :ref:`callbacks-and-errors`.
+
+        :param environ: A WSGI environment.
+        :param start_response: A callable accepting a status code,
+            a list of headers, and an optional exception context to
+            start the response.
+        """
+        ctx = self.request_context(environ)
+        error: t.Optional[BaseException] = None
+        try:
+            try:
+                ctx.push()
+                response = self.full_dispatch_request()
+            except Exception as e:
+                error = e
+                response = self.handle_exception(e)
+            except:  # noqa: B001
+                error = sys.exc_info()[1]
+                raise
+            return response(environ, start_response)
+        finally:
+            if self.should_ignore_error(error):
+                error = None
+            ctx.auto_pop(error)
+
+    def __call__(self, environ: dict, start_response: t.Callable) -> t.Any:
+        """The WSGI server calls the Flask application object as the
+        WSGI application. This calls :meth:`wsgi_app`, which can be
+        wrapped to apply middleware.
+        """
+        return self.wsgi_app(environ, start_response)