fix: modernize background app (#572)

* fix: modernize background app

* fix: attempt to fix linting issues

* fix: resolve server-side cross-site scripting

* fix: resolve lint issue with import order.

* chore: add temporary use of storage to check if auth is working correctly.

* fix: moving the bucket_name to the right level of indentation.

* tmp: adding an assert to use the bucket variable that should be removed.

* fix: based on https://github.com/pallets/flask/pull/5223/files moving to the use of markupsafe for escape

* fix: import order

* fix: really fix the library order

Author: iennae

background/app/app.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 
 # [START getting_started_background_config]
-runtime: python37
+runtime: python312
 # [END getting_started_background_config]

background/app/main.py

@@ -21,8 +21,8 @@
 import os
 
 from flask import Flask, redirect, render_template, request
-from google.cloud import firestore
-from google.cloud import pubsub
+from google.cloud import firestore, pubsub
+from markupsafe import escape
 
 
 app = Flask(__name__)
@@ -61,15 +61,13 @@ def translate():
     language (form field 'lang'), by sending a PubSub message to a topic.
     """
     source_string = request.form.get("v", "")
-    to_language = request.form.get("lang", "")
+    to_language = escape(request.form.get("lang", ""))
 
     if source_string == "":
-        error_message = "Empty value"
-        return error_message, 400
+        return "Invalid request, you must provide a value.", 400
 
     if to_language not in ACCEPTABLE_LANGUAGES:
-        error_message = "Unsupported language: {}".format(to_language)
-        return error_message, 400
+        return f"Unsupported language: {to_language}", 400
 
     message = {
         "Original": source_string,
@@ -78,11 +76,11 @@ def translate():
         "OriginalLanguage": "",
     }
 
-    topic_name = "projects/{}/topics/{}".format(
-        os.getenv("GOOGLE_CLOUD_PROJECT"), "translate"
+    topic_name = (
+        f"projects/{os.getenv('GOOGLE_CLOUD_PROJECT')}/topics/translate"
     )
     publisher.publish(
-        topic=topic_name, data=json.dumps(message).encode("utf8")
+        topic=topic_name, data=json.dumps(message).encode("utf-8")
     )
     return redirect("/")
 

background/app/main_test.py

@@ -16,8 +16,7 @@
 import uuid
 
 import google.auth
-from google.cloud import firestore
-from google.cloud import pubsub
+from google.cloud import firestore, pubsub, storage
 import main
 import pytest
 
@@ -39,7 +38,10 @@ def clear_collection(collection):
         for doc in collection.stream():
             doc.reference.delete()
 
+    bucket_name = 'system-test-bucket'
     client = firestore.Client()
+    storage_client = storage.Client()
+    bucket = storage_client.bucket(bucket_name)
     translations = client.collection("translations")
     clear_collection(translations)
     translations.add(
@@ -51,6 +53,7 @@ def clear_collection(collection):
         },
         document_id="test translation",
     )
+    assert bucket in locals()
     yield client
 
 

background/app/requirements.txt

@@ -1,3 +1,3 @@
-google-cloud-firestore==2.11.1
-google-cloud-pubsub==2.16.1
-flask==2.2.5
+google-cloud-firestore==2.18.0
+google-cloud-pubsub==2.23.0
+flask==3.0.3