deprecate passing script_info to factory

CHANGES.rst

@@ -9,6 +9,9 @@ Unreleased
 -   JSON support no longer uses simplejson. To use another JSON module,
     override ``app.json_encoder`` and ``json_decoder``. :issue:`3555`
 -   The ``encoding`` option to JSON functions is deprecated. :pr:`3562`
+-   Passing ``script_info`` to app factory functions is deprecated. This
+    was not portable outside the ``flask`` command. Use
+    ``click.get_current_context().obj`` if it's needed. :issue:`3552`
 -   Add :meth:`sessions.SessionInterface.get_cookie_name` to allow
     setting the session cookie name dynamically. :pr:`3369`
 -   Add :meth:`Config.from_file` to load config using arbitrary file

docs/cli.rst

@@ -75,13 +75,9 @@ Within the given import, the command looks for an application instance named
 found, the command looks for a factory function named ``create_app`` or
 ``make_app`` that returns an instance.
 
-When calling an application factory, if the factory takes an argument named
-``script_info``, then the :class:`~cli.ScriptInfo` instance is passed as a
-keyword argument. If the application factory takes only one argument and no
-parentheses follow the factory name, the :class:`~cli.ScriptInfo` instance
-is passed as a positional argument. If parentheses follow the factory name,
-their contents are parsed as Python literals and passes as arguments to the
-function. This means that strings must still be in quotes.
+If parentheses follow the factory name, their contents are parsed as
+Python literals and passed as arguments to the function. This means that
+strings must still be in quotes.
 
 
 Run the Development Server

src/flask/cli.py

@@ -5,6 +5,7 @@ import platform
 import re
 import sys
 import traceback
+import warnings
 from functools import update_wrapper
 from operator import attrgetter
 from threading import Lock
@@ -91,14 +92,22 @@ def call_factory(script_info, app_factory, arguments=()):
     the app_factory depending on that and the arguments provided.
     """
     args_spec = inspect.getfullargspec(app_factory)
-    arg_names = args_spec.args
-    arg_defaults = args_spec.defaults
 
-    if "script_info" in arg_names:
+    if "script_info" in args_spec.args:
+        warnings.warn(
+            "The 'script_info' argument is deprecated and will not be"
+            " passed to the app factory function in 2.1.",
+            DeprecationWarning,
+        )
         return app_factory(*arguments, script_info=script_info)
     elif arguments:
         return app_factory(*arguments)
-    elif not arguments and len(arg_names) == 1 and arg_defaults is None:
+    elif not arguments and len(args_spec.args) == 1 and args_spec.defaults is None:
+        warnings.warn(
+            "Script info is deprecated and will not be passed as the"
+            " first argument to the app factory function in 2.1.",
+            DeprecationWarning,
+        )
         return app_factory(script_info)
 
     return app_factory()
@@ -131,10 +140,8 @@ def _called_with_wrong_args(factory):
 
 
 def find_app_by_string(script_info, module, app_name):
-    """Checks if the given string is a variable name or a function. If it is a
-    function, it checks for specified arguments and whether it takes a
-    ``script_info`` argument and calls the function with the appropriate
-    arguments.
+    """Check if the given string is a variable name or a function. Call
+    a function to get the app instance, or return the variable directly.
     """
     from . import Flask
 

tests/test_apps/cliapp/factory.py

@@ -9,9 +9,5 @@ def create_app2(foo, bar):
     return Flask("_".join(["app2", foo, bar]))
 
 
-def create_app3(foo, script_info):
-    return Flask("_".join(["app3", foo, script_info.data["test"]]))
-
-
 def no_app():
     pass

tests/test_cli.py

@@ -67,32 +67,40 @@ def test_find_best_app(test_apps):
         def create_app():
             return Flask("appname")
 
-    assert isinstance(find_best_app(script_info, Module), Flask)
-    assert find_best_app(script_info, Module).name == "appname"
+    app = find_best_app(script_info, Module)
+    assert isinstance(app, Flask)
+    assert app.name == "appname"
 
     class Module:
         @staticmethod
         def create_app(foo):
             return Flask("appname")
 
-    assert isinstance(find_best_app(script_info, Module), Flask)
-    assert find_best_app(script_info, Module).name == "appname"
+    with pytest.deprecated_call(match="Script info"):
+        app = find_best_app(script_info, Module)
+
+    assert isinstance(app, Flask)
+    assert app.name == "appname"
 
     class Module:
         @staticmethod
         def create_app(foo=None, script_info=None):
             return Flask("appname")
 
-    assert isinstance(find_best_app(script_info, Module), Flask)
-    assert find_best_app(script_info, Module).name == "appname"
+    with pytest.deprecated_call(match="script_info"):
+        app = find_best_app(script_info, Module)
+
+    assert isinstance(app, Flask)
+    assert app.name == "appname"
 
     class Module:
         @staticmethod
         def make_app():
             return Flask("appname")
 
-    assert isinstance(find_best_app(script_info, Module), Flask)
-    assert find_best_app(script_info, Module).name == "appname"
+    app = find_best_app(script_info, Module)
+    assert isinstance(app, Flask)
+    assert app.name == "appname"
 
     class Module:
         myapp = Flask("appname1")
@@ -199,15 +207,12 @@ def test_prepare_import(request, value, path, result):
         ("cliapp.factory", 'create_app2("foo", "bar")', "app2_foo_bar"),
         # trailing comma space
         ("cliapp.factory", 'create_app2("foo", "bar", )', "app2_foo_bar"),
-        # takes script_info
-        ("cliapp.factory", 'create_app3("foo")', "app3_foo_spam"),
         # strip whitespace
         ("cliapp.factory", " create_app () ", "app"),
     ),
 )
 def test_locate_app(test_apps, iname, aname, result):
     info = ScriptInfo()
-    info.data["test"] = "spam"
     assert locate_app(info, iname, aname).name == result
 
 
@@ -286,7 +291,7 @@ def test_scriptinfo(test_apps, monkeypatch):
     assert app.name == "testapp"
     assert obj.load_app() is app
 
-    def create_app(info):
+    def create_app():
         return Flask("createapp")
 
     obj = ScriptInfo(create_app=create_app)
@@ -324,7 +329,7 @@ def test_with_appcontext(runner):
     def testcmd():
         click.echo(current_app.name)
 
-    obj = ScriptInfo(create_app=lambda info: Flask("testapp"))
+    obj = ScriptInfo(create_app=lambda: Flask("testapp"))
 
     result = runner.invoke(testcmd, obj=obj)
     assert result.exit_code == 0
@@ -350,7 +355,7 @@ def test_appgroup(runner):
     def test2():
         click.echo(current_app.name)
 
-    obj = ScriptInfo(create_app=lambda info: Flask("testappgroup"))
+    obj = ScriptInfo(create_app=lambda: Flask("testappgroup"))
 
     result = runner.invoke(cli, ["test"], obj=obj)
     assert result.exit_code == 0
@@ -364,7 +369,7 @@ def test_appgroup(runner):
 def test_flaskgroup(runner):
     """Test FlaskGroup."""
 
-    def create_app(info):
+    def create_app():
         return Flask("flaskgroup")
 
     @click.group(cls=FlaskGroup, create_app=create_app)
@@ -384,7 +389,7 @@ def test_flaskgroup(runner):
 def test_flaskgroup_debug(runner, set_debug_flag):
     """Test FlaskGroup debug flag behavior."""
 
-    def create_app(info):
+    def create_app():
         app = Flask("flaskgroup")
         app.debug = True
         return app
@@ -405,7 +410,7 @@ def test_flaskgroup_debug(runner, set_debug_flag):
 def test_print_exceptions(runner):
     """Print the stacktrace if the CLI."""
 
-    def create_app(info):
+    def create_app():
         raise Exception("oh no")
         return Flask("flaskgroup")
 
@@ -422,7 +427,7 @@ def test_print_exceptions(runner):
 class TestRoutes:
     @pytest.fixture
     def invoke(self, runner):
-        def create_app(info):
+        def create_app():
             app = Flask(__name__)
             app.testing = True
 
@@ -441,7 +446,7 @@ class TestRoutes:
 
     @pytest.fixture
     def invoke_no_routes(self, runner):
-        def create_app(info):
+        def create_app():
             app = Flask(__name__, static_folder=None)
             app.testing = True