🧹 Update Flask and Jinja2 to the latest version (#5348)

The advantage of upgrading will be that we'll have a new version of Jinja2, which we will be able to better template analysis on.

Some APIs have changed, and we've moved to vendoring `flask-commonmark` in since the original authors are not maintaining it anymore.

**How to test**

Everything should work the same.

app.py

@@ -25,7 +25,7 @@
                    redirect, request, send_file, url_for, jsonify,
                    send_from_directory, session)
 from flask_babel import Babel, gettext
-from flask_commonmark import Commonmark
+from website.flask_commonmark import Commonmark
 from flask_compress import Compress
 from urllib.parse import quote_plus
 
@@ -76,7 +76,12 @@
 # Use 5 minutes as a reasonable default for all files we load elsewise.
 app.config['SEND_FILE_MAX_AGE_DEFAULT'] = datetime.timedelta(minutes=5)
 
-babel = Babel(app)
+
+def get_locale():
+    return session.get("lang", request.accept_languages.best_match(ALL_LANGUAGES.keys(), 'en'))
+
+
+babel = Babel(app, locale_selector=get_locale)
 
 jinja_partials.register_extensions(app)
 app.template_filter('tojson')(proper_tojson)
@@ -258,11 +263,6 @@ def load_customized_adventures(level, customizations, into_adventures):
             into_adventures.append(adv)
 
 
-@babel.localeselector
-def get_locale():
-    return session.get("lang", request.accept_languages.best_match(ALL_LANGUAGES.keys(), 'en'))
-
-
 cdn.Cdn(app, os.getenv('CDN_PREFIX'), os.getenv('HEROKU_SLUG_COMMIT', 'dev'))
 
 

requirements.txt

@@ -1,11 +1,10 @@
-Flask==2.3.2
+Flask==3.0.2
 Werkzeug==3.0.1
 lark==1.1.1
 gunicorn==21.2.0
 flask-compress==1.4.0
 requests==2.31.0
 attrs>=22.2.0
-Flask-Commonmark==1.0.4
 bcrypt==3.2.0
 boto3>=1.16.50
 MarkupSafe==2.1.2
@@ -20,7 +19,7 @@ regex==2021.8.28
 retrying==1.3.3
 pytest==8.0.0
 parameterized==0.8.1
-Flask-Babel==2.0.0
+Flask-Babel==4.0.0
 iso3166~=2.0.2
 turtlethread>=0.0.6
 pre-commit==2.20.0
@@ -34,3 +33,4 @@ doit==0.36.0
 doit_watch>=0.1.0
 uflash>=2.0.0
 pyinstaller==6.3.0
+commonmark==0.9.1

website/flask_commonmark.py

@@ -0,0 +1,132 @@
+# -*- coding: utf-8 -*-
+# This file was copied from here:
+#   https://gitlab.com/doug.shawhan/flask-commonmark/-/blob/dev/flask_commonmark.py
+# We vendor it in because that package hasn't changed in 4 years, while the Flask
+# API has deprecated and removed the `Markup` class in the mean time and Jinja2
+# has replaced 'evalcontextfilter' with 'pass_eval_context'.
+"""
+flask_commonmark
+----------------
+
+Commonmark filter class for Flask. One may notice a similarity to Dan Colish's
+Flask-Markdown, from which I shamelessly copied a bunch of this. Does not have
+all the nice provisions for extension baked in, but probably does what you need.
+See https://commonmark.org/ for details.
+
+Usage
+::
+    from flask_commonmark import Commonmark
+    cm = Commonmark(app)
+
+    # or, if you are using the factory pattern
+
+    cm = Commonmark()
+    cm.init_app(app)
+
+    # Create routes in the usual way
+    @app.route("/commonmark")
+    def display_commonmark():
+        mycm = u"Hello, *commonmark* block."
+        return render_template("commonmark.html", mycm=mycm)
+
+
+Templates
+::
+    # one can just place raw markdown in the template. The filter expects
+    # your markdown to be fully left-aligned! Otherwise expect plaintext.
+    {% filter commonmark %}
+    # Nagasaki
+    1. Chew Terbaccy
+    1. Wicky-waky-woo
+    {% endfilter %}
+
+    # block style
+    {% filter commonmark %}{{ mycm }}{% endfilter %}
+
+    # inline style
+    {{mycm|commonmark}}
+
+:copyright: (c) 2019 by Doug Shawhan.
+:license: BSD, MIT see LICENSE for details.
+"""
+from markupsafe import Markup, escape
+from jinja2 import pass_eval_context
+import commonmark as cm
+
+
+class Commonmark(object):
+    """
+    Commonmark
+    ----------
+
+    Wrapper class for Commonmark (aka "common markdown"), objects.
+
+    Args:
+        app (obj):  Flask app instance
+        auto_escape (bool): Use Jinja2 auto_escape, default False
+    """
+
+    def __init__(self, app=False, auto_escape=False):
+        """
+        Create parser and renderer objects and auto_escape value.
+        Set filter.
+        """
+        if not app:
+            return
+
+        self.init_app(app, auto_escape=auto_escape)
+
+        app.jinja_env.filters.setdefault(
+            "commonmark", self.__build_filter(self.auto_escape)
+        )
+
+    def __call__(self, stream):
+        """
+        Render markdown stream.
+
+        Args:
+            stream (str):   template stream containing markdown tags
+
+        Returns:
+            html (str):  markdown rendered as html
+        """
+        return self.cm_render.render(self.cm_parse.parse(stream))
+
+    def __build_filter(self, app_auto_escape):
+        """
+        Jinja2 __build_filter
+
+        Args:
+            app_auto_escape (bool): auto_escape value (default False)
+        Returns:
+            commonmark_filter (obj):  context filter
+        """
+
+        @pass_eval_context
+        def commonmark_filter(eval_ctx, stream):
+            """
+            Called by Jinja2 when evaluating the Commonmark filter.
+
+            Args:
+                eval_ctx (obj): Jinja2 evaluation context
+                stream (str):   string to filter
+            """
+            __filter = self
+            if app_auto_escape and eval_ctx.autoescape:
+                return Markup(__filter(escape(stream)))
+            return Markup(__filter(stream))
+
+        return commonmark_filter
+
+    def init_app(self, app, auto_escape=False):
+        """
+        Create parser and renderer objects and auto_escape value.
+        Set filter.
+        """
+        self.auto_escape = auto_escape
+        self.cm_parse = cm.Parser()
+        self.cm_render = cm.HtmlRenderer()
+
+        app.jinja_env.filters.setdefault(
+            "commonmark", self.__build_filter(self.auto_escape)
+        )