From 59b40f0eeff3b87b207a8598dbb9a79023afd01b Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 13 Feb 2026 15:51:21 -0500
Subject: [PATCH 01/13] REFACTOR Pull apart get_closest_embeddings to make
 testing easier

---
 server/api/services/embedding_services.py | 161 +++++++++++++++-------
 1 file changed, 112 insertions(+), 49 deletions(-)

diff --git a/server/api/services/embedding_services.py b/server/api/services/embedding_services.py
index e35f7965..0720a9c8 100644
--- a/server/api/services/embedding_services.py
+++ b/server/api/services/embedding_services.py
@@ -11,18 +11,17 @@
 
 logger = logging.getLogger(__name__)
 
-def get_closest_embeddings(
-    user, message_data, document_name=None, guid=None, num_results=10
-):
+
+def build_query(user, embedding_vector, document_name=None, guid=None, num_results=10):
     """
-    Find the closest embeddings to a given message for a specific user.
+    Build an unevaluated QuerySet for the closest embeddings.
 
     Parameters
     ----------
     user : User
         The user whose uploaded documents will be searched
-    message_data : str
-        The input message to find similar embeddings for
+    embedding_vector : array-like
+        Pre-computed embedding vector to compare against
     document_name : str, optional
         Filter results to a specific document name
     guid : str, optional
@@ -32,59 +31,52 @@ def get_closest_embeddings(
 
     Returns
     -------
-    list[dict]
-        List of dictionaries containing embedding results with keys:
-        - name: document name
-        - text: embedded text content
-        - page_number: page number in source document
-        - chunk_number: chunk number within the document
-        - distance: L2 distance from query embedding
-        - file_id: GUID of the source file
+    QuerySet
+        Unevaluated Django QuerySet ordered by L2 distance, sliced to num_results
     """
-
-    encoding_start = time.time()
-    transformerModel = TransformerModel.get_instance().model
-    embedding_message = transformerModel.encode(message_data)
-    encoding_time = time.time() - encoding_start
-
-    db_query_start = time.time()
-
     # Django QuerySets are lazily evaluated
     if user.is_authenticated:
         # User sees their own files + files uploaded by superusers
-        closest_embeddings_query = (
-            Embeddings.objects.filter(
-                Q(upload_file__uploaded_by=user) | Q(upload_file__uploaded_by__is_superuser=True)
-            )
-            .annotate(
-                distance=L2Distance("embedding_sentence_transformers", embedding_message)
-            )
-            .order_by("distance")
+        queryset = Embeddings.objects.filter(
+            Q(upload_file__uploaded_by=user) | Q(upload_file__uploaded_by__is_superuser=True)
         )
     else:
         # Unauthenticated users only see superuser-uploaded files
-        closest_embeddings_query = (
-            Embeddings.objects.filter(upload_file__uploaded_by__is_superuser=True)
-            .annotate(
-                distance=L2Distance("embedding_sentence_transformers", embedding_message)
-            )
-            .order_by("distance")
-        )
+        queryset = Embeddings.objects.filter(upload_file__uploaded_by__is_superuser=True)
+
+    queryset = (
+        queryset
+        .annotate(distance=L2Distance("embedding_sentence_transformers", embedding_vector))
+        .order_by("distance")
+    )
 
     # Filtering to a document GUID takes precedence over a document name
     if guid:
-        closest_embeddings_query = closest_embeddings_query.filter(
-            upload_file__guid=guid
-        )
+        queryset = queryset.filter(upload_file__guid=guid)
     elif document_name:
-        closest_embeddings_query = closest_embeddings_query.filter(name=document_name)
+        queryset = queryset.filter(name=document_name)
 
     # Slicing is equivalent to SQL's LIMIT clause
-    closest_embeddings_query = closest_embeddings_query[:num_results]
+    return queryset[:num_results]
+
+
+def format_results(queryset):
+    """
+    Evaluate a QuerySet and return a list of result dicts.
+
+    Parameters
+    ----------
+    queryset : iterable
+        Iterable of Embeddings objects (or any objects with the expected attributes)
 
+    Returns
+    -------
+    list[dict]
+        List of dicts with keys: name, text, page_number, chunk_number, distance, file_id
+    """
     # Iterating evaluates the QuerySet and hits the database
     # TODO: Research improving the query evaluation performance
-    results = [
+    return [
         {
             "name": obj.name,
             "text": obj.text,
@@ -93,13 +85,36 @@ def get_closest_embeddings(
             "distance": obj.distance,
             "file_id": obj.upload_file.guid if obj.upload_file else None,
         }
-        for obj in closest_embeddings_query
+        for obj in queryset
     ]
 
-    db_query_time = time.time() - db_query_start
 
+def log_search_usage(
+    results, message_data, user, guid, document_name, num_results, encoding_time, db_query_time
+):
+    """
+    Create a SemanticSearchUsage record. Swallows exceptions so search isn't interrupted.
+
+    Parameters
+    ----------
+    results : list[dict]
+        The search results, each containing a "distance" key
+    message_data : str
+        The original search query text
+    user : User
+        The user who performed the search
+    guid : str or None
+        Document GUID filter used in the search
+    document_name : str or None
+        Document name filter used in the search
+    num_results : int
+        Number of results requested
+    encoding_time : float
+        Time in seconds to encode the query
+    db_query_time : float
+        Time in seconds for the database query
+    """
     try:
-        # Handle user having no uploaded docs or doc filtering returning no matches
         if results:
             distances = [r["distance"] for r in results]
             SemanticSearchUsage.objects.create(
@@ -113,11 +128,10 @@ def get_closest_embeddings(
                 num_results_returned=len(results),
                 max_distance=max(distances),
                 median_distance=median(distances),
-                min_distance=min(distances)
+                min_distance=min(distances),
             )
         else:
             logger.warning("Semantic search returned no results")
-
             SemanticSearchUsage.objects.create(
                 query_text=message_data,
                 user=user if (user and user.is_authenticated) else None,
@@ -129,9 +143,58 @@ def get_closest_embeddings(
                 num_results_returned=0,
                 max_distance=None,
                 median_distance=None,
-                min_distance=None
+                min_distance=None,
             )
     except Exception as e:
         logger.error(f"Failed to create semantic search usage database record: {e}")
 
+
+def get_closest_embeddings(
+    user, message_data, document_name=None, guid=None, num_results=10
+):
+    """
+    Find the closest embeddings to a given message for a specific user.
+
+    Parameters
+    ----------
+    user : User
+        The user whose uploaded documents will be searched
+    message_data : str
+        The input message to find similar embeddings for
+    document_name : str, optional
+        Filter results to a specific document name
+    guid : str, optional
+        Filter results to a specific document GUID (takes precedence over document_name)
+    num_results : int, default 10
+        Maximum number of results to return
+
+    Returns
+    -------
+    list[dict]
+        List of dictionaries containing embedding results with keys:
+        - name: document name
+        - text: embedded text content
+        - page_number: page number in source document
+        - chunk_number: chunk number within the document
+        - distance: L2 distance from query embedding
+        - file_id: GUID of the source file
+
+    Notes
+    -----
+    Creates a SemanticSearchUsage record. Swallows exceptions so search isn't interrupted.
+    """
+    encoding_start = time.time()
+    model = TransformerModel.get_instance().model
+    embedding_vector = model.encode(message_data)
+    encoding_time = time.time() - encoding_start
+
+    db_query_start = time.time()
+    queryset = build_query(user, embedding_vector, document_name, guid, num_results)
+    results = format_results(queryset)
+    db_query_time = time.time() - db_query_start
+
+    log_search_usage(
+        results, message_data, user, guid, document_name, num_results, encoding_time, db_query_time
+    )
+
     return results

From 3ffb74af318cc927d9c11ba37e63a3093d5ecfc6 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 13 Feb 2026 16:12:49 -0500
Subject: [PATCH 02/13] ADD Add infra required to run pytest

---
 .github/workflows/python-app.yml | 5 +++++
 server/pytest.ini                | 3 +++
 server/requirements.txt          | 4 +++-
 3 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 server/pytest.ini

diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index dcb7a4bb..41bc74d9 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -27,3 +27,8 @@ jobs:
       run: pipx install ruff
     - name: Lint code with Ruff
       run: ruff check --output-format=github --target-version=py39
+    - name: Install test dependencies
+      run: pip install -r server/requirements.txt
+      # Discover and run all files matching test_*.py or *_test.py under server/
+    - name: Run tests
+      run: pytest server/ -v
diff --git a/server/pytest.ini b/server/pytest.ini
new file mode 100644
index 00000000..235b9752
--- /dev/null
+++ b/server/pytest.ini
@@ -0,0 +1,3 @@
+[pytest]
+DJANGO_SETTINGS_MODULE = balancer_backend.settings
+pythonpath = .
diff --git a/server/requirements.txt b/server/requirements.txt
index bbaf7bc9..001708e9 100644
--- a/server/requirements.txt
+++ b/server/requirements.txt
@@ -18,4 +18,6 @@ sentence_transformers
 PyMuPDF==1.24.0
 Pillow
 pytesseract
-anthropic
\ No newline at end of file
+anthropic
+pytest
+pytest-django
\ No newline at end of file

From 12b09a733a1dc79b8fbec63d358d4354764a5116 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 13 Feb 2026 16:33:41 -0500
Subject: [PATCH 03/13] ADD Start adding tests for embedding_services"

---
 server/api/services/embedding_services.py     |  8 +-
 .../api/services/test_embedding_services.py   | 85 +++++++++++++++++++
 2 files changed, 89 insertions(+), 4 deletions(-)
 create mode 100644 server/api/services/test_embedding_services.py

diff --git a/server/api/services/embedding_services.py b/server/api/services/embedding_services.py
index 0720a9c8..3fa9bb68 100644
--- a/server/api/services/embedding_services.py
+++ b/server/api/services/embedding_services.py
@@ -60,7 +60,7 @@ def build_query(user, embedding_vector, document_name=None, guid=None, num_resul
     return queryset[:num_results]
 
 
-def format_results(queryset):
+def evaluate_query(queryset):
     """
     Evaluate a QuerySet and return a list of result dicts.
 
@@ -89,7 +89,7 @@ def format_results(queryset):
     ]
 
 
-def log_search_usage(
+def log_usage(
     results, message_data, user, guid, document_name, num_results, encoding_time, db_query_time
 ):
     """
@@ -190,10 +190,10 @@ def get_closest_embeddings(
 
     db_query_start = time.time()
     queryset = build_query(user, embedding_vector, document_name, guid, num_results)
-    results = format_results(queryset)
+    results = evaluate_query(queryset)
     db_query_time = time.time() - db_query_start
 
-    log_search_usage(
+    log_usage(
         results, message_data, user, guid, document_name, num_results, encoding_time, db_query_time
     )
 
diff --git a/server/api/services/test_embedding_services.py b/server/api/services/test_embedding_services.py
new file mode 100644
index 00000000..677c1e7b
--- /dev/null
+++ b/server/api/services/test_embedding_services.py
@@ -0,0 +1,85 @@
+from unittest.mock import MagicMock, patch
+
+from api.services.embedding_services import evaluate_query, log_usage
+
+
+def test_evaluate_query_maps_fields():
+    obj = MagicMock()
+    obj.name = "doc.pdf"
+    obj.text = "some text"
+    obj.page_num = 3
+    obj.chunk_number = 1
+    obj.distance = 0.42
+    obj.upload_file.guid = "abc-123"
+
+    results = evaluate_query([obj])
+
+    assert results == [
+        {
+            "name": "doc.pdf",
+            "text": "some text",
+            "page_number": 3,
+            "chunk_number": 1,
+            "distance": 0.42,
+            "file_id": "abc-123",
+        }
+    ]
+
+
+def test_evaluate_query_none_upload_file():
+    obj = MagicMock()
+    obj.name = "doc.pdf"
+    obj.text = "some text"
+    obj.page_num = 1
+    obj.chunk_number = 0
+    obj.distance = 1.0
+    obj.upload_file = None
+
+    results = evaluate_query([obj])
+
+    assert results[0]["file_id"] is None
+
+
+@patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
+def test_log_usage_computes_distance_stats(mock_create):
+    results = [{"distance": 1.0}, {"distance": 3.0}, {"distance": 2.0}]
+    user = MagicMock(is_authenticated=True)
+
+    log_usage(
+        results,
+        message_data="test query",
+        user=user,
+        guid=None,
+        document_name=None,
+        num_results=10,
+        encoding_time=0.1,
+        db_query_time=0.2,
+    )
+
+    mock_create.assert_called_once()
+    kwargs = mock_create.call_args.kwargs
+    assert kwargs["min_distance"] == 1.0
+    assert kwargs["max_distance"] == 3.0
+    assert kwargs["median_distance"] == 2.0
+    assert kwargs["num_results_returned"] == 3
+
+
+@patch(
+    "api.services.embedding_services.SemanticSearchUsage.objects.create",
+    side_effect=Exception("DB error"),
+)
+def test_log_usage_swallows_exceptions(mock_create):
+    results = [{"distance": 1.0}]
+    user = MagicMock(is_authenticated=True)
+
+    # pytest fails the test if it catches unhandled Exception
+    log_usage(
+        results,
+        message_data="test query",
+        user=user,
+        guid=None,
+        document_name=None,
+        num_results=10,
+        encoding_time=0.1,
+        db_query_time=0.2,
+    )

From da9afaa905a43218e1f947360aa141662359e1aa Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Tue, 17 Feb 2026 14:40:13 -0500
Subject: [PATCH 04/13] DOC Add a note about running pytest in the README

---
 README.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/README.md b/README.md
index f1cea06b..15018d37 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,11 @@ df = pd.read_sql(query, engine)
 
 #### Django REST
 - The email and password are set in `server/api/management/commands/createsu.py`
+- Backend tests can be run using `pytest` by running the below command inside the running backend container:
+
+```
+docker compose exec backend pytest api/ -v
+```
 
 ## Local Kubernetes Deployment
 

From 5ce77823c25f0a45fbcdc828e13214b515496bc2 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 27 Feb 2026 16:09:05 -0500
Subject: [PATCH 05/13] Preload SentenceTransformer model at Django startup
 before traffic is routed to the application instance

---
 server/api/apps.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/server/api/apps.py b/server/api/apps.py
index 66656fd2..4d502cba 100644
--- a/server/api/apps.py
+++ b/server/api/apps.py
@@ -4,3 +4,7 @@
 class ApiConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'api'
+
+    def ready(self):
+        from .services.sentencetTransformer_model import TransformerModel
+        TransformerModel.get_instance()

From 795f21885e766de9f6379319c5555ef7db48d989 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Wed, 11 Mar 2026 13:09:14 -0400
Subject: [PATCH 06/13] Run python-app workflow on pushes and PRs to develop
 branch

---
 .github/workflows/python-app.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index 41bc74d9..a6c07075 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -5,9 +5,9 @@ name: Python application
 
 on:
   push:
-    branches: [ "listOfMed" ]
+    branches: [ "develop" ]
   pull_request:
-    branches: [ "listOfMed" ]
+    branches: [ "develop" ]
 
 permissions:
   contents: read

From d498a0057008b1b2c80bdb176e5940940899639b Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Thu, 19 Mar 2026 13:15:47 -0400
Subject: [PATCH 07/13] =?UTF-8?q?Pytest=20won=E2=80=99t=20automatically=20?=
 =?UTF-8?q?discover=20config=20files=20in=20subdirectories?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .github/workflows/python-app.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index a6c07075..2afa2828 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -29,6 +29,6 @@ jobs:
       run: ruff check --output-format=github --target-version=py39
     - name: Install test dependencies
       run: pip install -r server/requirements.txt
-      # Discover and run all files matching test_*.py or *_test.py under server/
+      # Pytest won’t automatically discover config files in subdirectories
     - name: Run tests
-      run: pytest server/ -v
+      run: pytest -c server/pytest.ini server/ -v

From 3824d81ae0fb722383f7e80df07ca7ba28d0c4e6 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Thu, 19 Mar 2026 13:47:52 -0400
Subject: [PATCH 08/13] Suppress E402 import violations

---
 evaluation/evals.py             | 16 ++++++++--------
 server/balancer_backend/urls.py |  6 +++---
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/evaluation/evals.py b/evaluation/evals.py
index 8eb7e9e6..5110076f 100755
--- a/evaluation/evals.py
+++ b/evaluation/evals.py
@@ -21,18 +21,18 @@
 # Ensure the parent directory is in the path to import ModelFactory
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
-import argparse
-import logging
-import asyncio
-import time
+import argparse  # noqa: E402
+import logging  # noqa: E402
+import asyncio  # noqa: E402
+import time  # noqa: E402
 
-import pandas as pd
+import pandas as pd  # noqa: E402
 
 # lighteval depends on `sentencepiece` and it only has prebuilt wheels for Python 3.11 or below
-from lighteval.tasks.requests import Doc
-from lighteval.metrics.metrics_sample import Extractiveness
+from lighteval.tasks.requests import Doc  # noqa: E402
+from lighteval.metrics.metrics_sample import Extractiveness  # noqa: E402
 
-from server.api.services.llm_services import ModelFactory
+from server.api.services.llm_services import ModelFactory  # noqa: E402
 
 logging.basicConfig(
     level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s"
diff --git a/server/balancer_backend/urls.py b/server/balancer_backend/urls.py
index 55bd2032..cdb92dbb 100644
--- a/server/balancer_backend/urls.py
+++ b/server/balancer_backend/urls.py
@@ -58,9 +58,9 @@
     path("api/redoc/", SpectacularRedocView.as_view(url_name="schema"), name="redoc"),
 ]
 
-import os
-from django.conf import settings
-from django.http import HttpResponseNotFound
+import os # noqa: E402
+from django.conf import settings # noqa: E402
+from django.http import HttpResponseNotFound # noqa: E402
 
 
 def spa_fallback(request):

From 46e9969dade55777098286cd6316bc18444e5b1f Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 20 Mar 2026 12:00:44 -0400
Subject: [PATCH 09/13] Add build_query tests and document coverage gaps in
 embedding_services

---
 server/api/services/embedding_services.py     |   1 +
 .../api/services/test_embedding_services.py   | 202 +++++++++++++++++-
 2 files changed, 201 insertions(+), 2 deletions(-)

diff --git a/server/api/services/embedding_services.py b/server/api/services/embedding_services.py
index 3fa9bb68..aca99133 100644
--- a/server/api/services/embedding_services.py
+++ b/server/api/services/embedding_services.py
@@ -2,6 +2,7 @@
 import logging
 from statistics import median
 
+# filter() only does ADD logic
 from django.db.models import Q
 from pgvector.django import L2Distance
 
diff --git a/server/api/services/test_embedding_services.py b/server/api/services/test_embedding_services.py
index 677c1e7b..ea322645 100644
--- a/server/api/services/test_embedding_services.py
+++ b/server/api/services/test_embedding_services.py
@@ -1,9 +1,175 @@
 from unittest.mock import MagicMock, patch
 
-from api.services.embedding_services import evaluate_query, log_usage
+from django.db.models import Q
 
+from api.services.embedding_services import build_query, evaluate_query, log_usage
+
+# ---------------------------------------------------------------------------
+# build_query tests
+#
+# build_query only constructs a lazy Django QuerySet — it never evaluates it
+# (no iteration, .get(), .exists(), etc.), so no database is needed.
+#
+# We patch Embeddings.objects so every chained ORM call (.filter, .annotate,
+# .order_by, __getitem__) returns a MagicMock instead of hitting the DB.
+# All assertions inspect which methods were called with which arguments.
+# ---------------------------------------------------------------------------
+
+# Only forwarded to L2Distance
+EMBEDDING_VECTOR = [0.1, 0.2, 0.3]  
+
+# Test authenticated/unauthenticated user access control
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_authenticated_uses_or_filter(mock_objects):
+    # An authenticated user should see their own files OR files uploaded by a
+    # superuser. The initial filter must use an OR-connected Q expression.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR)
+
+    # Q objects support equality comparison in pure Python — no DB needed.
+    expected_q = Q(upload_file__uploaded_by=user) | Q(upload_file__uploaded_by__is_superuser=True)
+    actual_q = mock_objects.filter.call_args.args[0]
+    assert actual_q == expected_q
+
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_unauthenticated_uses_superuser_only_filter(mock_objects):
+    # An unauthenticated user may only see files uploaded by superusers.
+    # The OR branch for the user's own files must NOT be present.
+    user = MagicMock(is_authenticated=False)
+
+    build_query(user, EMBEDDING_VECTOR)
+
+    expected_q = Q(upload_file__uploaded_by__is_superuser=True)
+    actual_q = mock_objects.filter.call_args.args[0]
+    assert actual_q == expected_q
+    
+# Test application of annotate and order_by
+
+# TODO: Strengthen test_build_query_annotates_and_orders_by_distance to also
+#       assert the *arguments* to annotate — specifically that it receives
+#       distance=L2Distance("embedding_sentence_transformers", EMBEDDING_VECTOR).
+#       Currently only the call count is checked, so a wrong field name or a
+#       dropped vector would go undetected.
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_annotates_and_orders_by_distance(mock_objects):
+    # Regardless of other arguments, annotate(distance=L2Distance(...)) and
+    # order_by("distance") must always be applied to the queryset.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR)
+
+    # Retrieve the mock chain that .filter() returned, then check its methods.
+    filtered_qs = mock_objects.filter.return_value
+    filtered_qs.annotate.assert_called_once()
+    filtered_qs.annotate.return_value.order_by.assert_called_once_with("distance")
+
+# Test guid-over-document precedence logic
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_no_document_filter_when_both_none(mock_objects):
+    # When neither guid nor document_name is provided, only the access-control
+    # filter should fire — no secondary filter call for a document.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, document_name=None, guid=None)
+
+    # Exactly one filter call: the auth/access-control filter.
+    assert mock_objects.filter.call_count == 1
+
+
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_guid_takes_precedence_over_document_name(mock_objects):
+    # When both guid and document_name are provided, the guid branch runs and
+    # the document_name branch is skipped entirely (only two filter calls total).
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, guid="abc-123", document_name="study.pdf")
+
+    # Two calls: auth filter + guid filter. No third call for document_name.
+    assert mock_objects.filter.call_count == 2
+
+    # The second filter must use upload_file__guid, not name.
+    # We follow the mock chain to the queryset that .annotate().order_by() returned.
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    ordered_qs.filter.assert_called_once_with(upload_file__guid="abc-123")
+
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_guid_filter_applied(mock_objects):
+    # When only guid is given, a second filter on upload_file__guid is applied.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, guid="doc-guid-456")
+
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    ordered_qs.filter.assert_called_once_with(upload_file__guid="doc-guid-456")
+
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_document_name_filter_applied(mock_objects):
+    # When only document_name is given (guid is None), a second filter on
+    # name is applied instead of upload_file__guid.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, document_name="study.pdf", guid=None)
+
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    ordered_qs.filter.assert_called_once_with(name="study.pdf")
+    
+    
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_empty_string_guid_falls_back_to_document_name(mock_objects):
+    # An empty-string guid is falsy in Python, so it should not trigger the
+    # guid branch. The document_name filter should fire instead. This guards
+    # against callers passing guid="" from an unset form field.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, guid="", document_name="fallback.pdf")
+
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    ordered_qs.filter.assert_called_once_with(name="fallback.pdf")
+
+# Cover LIMIT slicing
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_respects_num_results(mock_objects):
+    # num_results controls the SQL LIMIT via queryset slicing. Verify that a
+    # non-default value propagates correctly to the __getitem__ call.
+    user = MagicMock(is_authenticated=True)
+
+    build_query(user, EMBEDDING_VECTOR, num_results=5)
+
+    # Django translates qs[:5] into qs.__getitem__(slice(None, 5, None)).
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    ordered_qs.__getitem__.assert_called_once_with(slice(None, 5, None))
+
+@patch("api.services.embedding_services.Embeddings.objects")
+def test_build_query_returns_unevaluated_queryset(mock_objects):
+    # build_query must NOT evaluate the queryset (no list(), no iteration).
+    # The return value should be the mock produced by the final __getitem__ call.
+    user = MagicMock(is_authenticated=True)
+
+    result = build_query(user, EMBEDDING_VECTOR)
+
+    ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
+    assert result is ordered_qs.__getitem__.return_value
+    assert not isinstance(result, list)
+
+
+# ---------------------------------------------------------------------------
+# evaluate_query tests
+# ---------------------------------------------------------------------------
+
+# TODO: Add test for empty queryset — evaluate_query([]) should return [].
 
 def test_evaluate_query_maps_fields():
+    # Verify that each Embeddings model attribute is mapped to the correct
+    # output dict key. Note the rename: obj.page_num -> result["page_number"].
     obj = MagicMock()
     obj.name = "doc.pdf"
     obj.text = "some text"
@@ -27,6 +193,8 @@ def test_evaluate_query_maps_fields():
 
 
 def test_evaluate_query_none_upload_file():
+    # When upload_file is None (e.g. the FK was deleted), file_id must be None
+    # rather than raising an AttributeError on None.guid.
     obj = MagicMock()
     obj.name = "doc.pdf"
     obj.text = "some text"
@@ -39,9 +207,26 @@ def test_evaluate_query_none_upload_file():
 
     assert results[0]["file_id"] is None
 
+# ---------------------------------------------------------------------------
+# log_usage tests
+# ---------------------------------------------------------------------------
+
+# TODO: Add test for empty results list — log_usage([]) hits the else branch and
+#       should call SemanticSearchUsage.objects.create with num_results_returned=0
+#       and max_distance=None, median_distance=None, min_distance=None.
+
+# TODO: Add test for unauthenticated user — user.is_authenticated=False should
+#       result in user=None being stored in the SemanticSearchUsage record.
+
+# TODO: Add test for user=None — passing None directly as the user argument
+#       should also store user=None (the expression `user if (user and
+#       user.is_authenticated) else None` handles both cases, but only the
+#       authenticated path is currently exercised).
 
 @patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
 def test_log_usage_computes_distance_stats(mock_create):
+    # Verify min, max, and median are computed correctly from the distance
+    # values in the results list and forwarded to the DB record.
     results = [{"distance": 1.0}, {"distance": 3.0}, {"distance": 2.0}]
     user = MagicMock(is_authenticated=True)
 
@@ -69,10 +254,12 @@ def test_log_usage_computes_distance_stats(mock_create):
     side_effect=Exception("DB error"),
 )
 def test_log_usage_swallows_exceptions(mock_create):
+    # log_usage must not propagate exceptions — a logging failure should never
+    # interrupt the caller's search flow.
+    # pytest fails the test if it catches unhandled Exception
     results = [{"distance": 1.0}]
     user = MagicMock(is_authenticated=True)
 
-    # pytest fails the test if it catches unhandled Exception
     log_usage(
         results,
         message_data="test query",
@@ -83,3 +270,14 @@ def test_log_usage_swallows_exceptions(mock_create):
         encoding_time=0.1,
         db_query_time=0.2,
     )
+
+
+# ---------------------------------------------------------------------------
+# get_closest_embeddings tests
+# ---------------------------------------------------------------------------
+
+# TODO: Add smoke test for get_closest_embeddings verifying the wiring between
+#       its three steps: encode → build_query → evaluate_query → log_usage.
+#       Patch TransformerModel.get_instance, build_query, evaluate_query, and
+#       log_usage. Assert that evaluate_query receives the queryset returned by
+#       build_query, and that the function returns evaluate_query's result.

From 64a19ef56dad988d1a2ea61a0b409c7878d0370c Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 20 Mar 2026 12:39:51 -0400
Subject: [PATCH 10/13] Fill test gaps in test_embedding_services

---
 server/api/services/embedding_services.py     |   2 +-
 .../api/services/test_embedding_services.py   | 149 ++++++++++++++----
 2 files changed, 119 insertions(+), 32 deletions(-)

diff --git a/server/api/services/embedding_services.py b/server/api/services/embedding_services.py
index aca99133..dada28a2 100644
--- a/server/api/services/embedding_services.py
+++ b/server/api/services/embedding_services.py
@@ -2,7 +2,7 @@
 import logging
 from statistics import median
 
-# filter() only does ADD logic
+# Django filter() only does ADD logic
 from django.db.models import Q
 from pgvector.django import L2Distance
 
diff --git a/server/api/services/test_embedding_services.py b/server/api/services/test_embedding_services.py
index ea322645..8cbc1be9 100644
--- a/server/api/services/test_embedding_services.py
+++ b/server/api/services/test_embedding_services.py
@@ -1,20 +1,21 @@
 from unittest.mock import MagicMock, patch
 
 from django.db.models import Q
+from pgvector.django import L2Distance
 
-from api.services.embedding_services import build_query, evaluate_query, log_usage
+from api.services.embedding_services import (
+    build_query,
+    evaluate_query,
+    get_closest_embeddings,
+    log_usage,
+)
 
 # ---------------------------------------------------------------------------
 # build_query tests
-#
-# build_query only constructs a lazy Django QuerySet — it never evaluates it
-# (no iteration, .get(), .exists(), etc.), so no database is needed.
-#
-# We patch Embeddings.objects so every chained ORM call (.filter, .annotate,
-# .order_by, __getitem__) returns a MagicMock instead of hitting the DB.
-# All assertions inspect which methods were called with which arguments.
 # ---------------------------------------------------------------------------
 
+# All assertions inspect which methods and arguments were called on Embeddings.objects
+
 # Only forwarded to L2Distance
 EMBEDDING_VECTOR = [0.1, 0.2, 0.3]  
 
@@ -48,12 +49,6 @@ def test_build_query_unauthenticated_uses_superuser_only_filter(mock_objects):
     
 # Test application of annotate and order_by
 
-# TODO: Strengthen test_build_query_annotates_and_orders_by_distance to also
-#       assert the *arguments* to annotate — specifically that it receives
-#       distance=L2Distance("embedding_sentence_transformers", EMBEDDING_VECTOR).
-#       Currently only the call count is checked, so a wrong field name or a
-#       dropped vector would go undetected.
-
 @patch("api.services.embedding_services.Embeddings.objects")
 def test_build_query_annotates_and_orders_by_distance(mock_objects):
     # Regardless of other arguments, annotate(distance=L2Distance(...)) and
@@ -67,6 +62,12 @@ def test_build_query_annotates_and_orders_by_distance(mock_objects):
     filtered_qs.annotate.assert_called_once()
     filtered_qs.annotate.return_value.order_by.assert_called_once_with("distance")
 
+    # L2Distance is a Django Func subclass, which implements __eq__ by comparing
+    # class and source expressions — so we can assert the exact field name and
+    # vector without patching L2Distance itself.
+    actual_distance_expr = filtered_qs.annotate.call_args.kwargs["distance"]
+    assert actual_distance_expr == L2Distance("embedding_sentence_transformers", EMBEDDING_VECTOR)
+
 # Test guid-over-document precedence logic
 
 @patch("api.services.embedding_services.Embeddings.objects")
@@ -165,7 +166,10 @@ def test_build_query_returns_unevaluated_queryset(mock_objects):
 # evaluate_query tests
 # ---------------------------------------------------------------------------
 
-# TODO: Add test for empty queryset — evaluate_query([]) should return [].
+def test_evaluate_query_empty_queryset():
+    # An empty iterable should return an empty list, not raise an exception.
+    assert evaluate_query([]) == []
+
 
 def test_evaluate_query_maps_fields():
     # Verify that each Embeddings model attribute is mapped to the correct
@@ -193,8 +197,8 @@ def test_evaluate_query_maps_fields():
 
 
 def test_evaluate_query_none_upload_file():
-    # When upload_file is None (e.g. the FK was deleted), file_id must be None
-    # rather than raising an AttributeError on None.guid.
+    # When upload_file is None, file_id must be None rather than raising
+    # an AttributeError on None.guid.
     obj = MagicMock()
     obj.name = "doc.pdf"
     obj.text = "some text"
@@ -211,17 +215,71 @@ def test_evaluate_query_none_upload_file():
 # log_usage tests
 # ---------------------------------------------------------------------------
 
-# TODO: Add test for empty results list — log_usage([]) hits the else branch and
-#       should call SemanticSearchUsage.objects.create with num_results_returned=0
-#       and max_distance=None, median_distance=None, min_distance=None.
+@patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
+def test_log_usage_empty_results(mock_create):
+    # Empty results hits the else branch. The record should still be created
+    # with num_results_returned=0 and all distance fields set to None.
+    user = MagicMock(is_authenticated=True)
+
+    log_usage(
+        [],
+        message_data="test query",
+        user=user,
+        guid=None,
+        document_name=None,
+        num_results=10,
+        encoding_time=0.1,
+        db_query_time=0.2,
+    )
+
+    mock_create.assert_called_once()
+    kwargs = mock_create.call_args.kwargs
+    assert kwargs["num_results_returned"] == 0
+    assert kwargs["max_distance"] is None
+    assert kwargs["median_distance"] is None
+    assert kwargs["min_distance"] is None
+
+
+@patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
+def test_log_usage_unauthenticated_user_stored_as_none(mock_create):
+    # An unauthenticated user should be stored as None in the DB record, not as
+    # the user object itself, so the FK constraint is not violated.
+    user = MagicMock(is_authenticated=False)
+
+    log_usage(
+        [{"distance": 1.0}],
+        message_data="test query",
+        user=user,
+        guid=None,
+        document_name=None,
+        num_results=10,
+        encoding_time=0.1,
+        db_query_time=0.2,
+    )
+
+    kwargs = mock_create.call_args.kwargs
+    assert kwargs["user"] is None
+
+
+@patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
+def test_log_usage_none_user_stored_as_none(mock_create):
+    # Passing user=None directly (e.g. from an anonymous request) should also
+    # store None — the expression `user if (user and user.is_authenticated)`
+    # short-circuits on the falsy None before accessing .is_authenticated.
+    log_usage(
+        [{"distance": 1.0}],
+        message_data="test query",
+        user=None,
+        guid=None,
+        document_name=None,
+        num_results=10,
+        encoding_time=0.1,
+        db_query_time=0.2,
+    )
 
-# TODO: Add test for unauthenticated user — user.is_authenticated=False should
-#       result in user=None being stored in the SemanticSearchUsage record.
+    kwargs = mock_create.call_args.kwargs
+    assert kwargs["user"] is None
 
-# TODO: Add test for user=None — passing None directly as the user argument
-#       should also store user=None (the expression `user if (user and
-#       user.is_authenticated) else None` handles both cases, but only the
-#       authenticated path is currently exercised).
 
 @patch("api.services.embedding_services.SemanticSearchUsage.objects.create")
 def test_log_usage_computes_distance_stats(mock_create):
@@ -276,8 +334,37 @@ def test_log_usage_swallows_exceptions(mock_create):
 # get_closest_embeddings tests
 # ---------------------------------------------------------------------------
 
-# TODO: Add smoke test for get_closest_embeddings verifying the wiring between
-#       its three steps: encode → build_query → evaluate_query → log_usage.
-#       Patch TransformerModel.get_instance, build_query, evaluate_query, and
-#       log_usage. Assert that evaluate_query receives the queryset returned by
-#       build_query, and that the function returns evaluate_query's result.
+@patch("api.services.embedding_services.log_usage")
+@patch("api.services.embedding_services.evaluate_query")
+@patch("api.services.embedding_services.build_query")
+@patch("api.services.embedding_services.TransformerModel")
+def test_get_closest_embeddings_wiring(mock_transformer, mock_build, mock_evaluate, mock_log):
+    # Smoke test verifying that get_closest_embeddings correctly wires together
+    # encode → build_query → evaluate_query → log_usage and returns the results.
+    user = MagicMock(is_authenticated=True)
+
+    # Simulate the model encoding the message to a vector.
+    fake_vector = [0.1, 0.2, 0.3]
+    mock_transformer.get_instance.return_value.model.encode.return_value = fake_vector
+
+    # build_query returns a queryset; evaluate_query turns it into a results list.
+    fake_queryset = MagicMock()
+    mock_build.return_value = fake_queryset
+    fake_results = [{"name": "doc.pdf", "distance": 0.5}]
+    mock_evaluate.return_value = fake_results
+
+    result = get_closest_embeddings(user, "some query", document_name="doc.pdf", guid=None, num_results=5)
+
+    # The encoded vector must be forwarded to build_query.
+    mock_build.assert_called_once_with(user, fake_vector, "doc.pdf", None, 5)
+
+    # evaluate_query must receive the queryset that build_query returned.
+    mock_evaluate.assert_called_once_with(fake_queryset)
+
+    # log_usage must be called with the results and original parameters.
+    mock_log.assert_called_once()
+    log_kwargs = mock_log.call_args.args
+    assert log_kwargs[0] is fake_results
+
+    # The function must return evaluate_query's result unchanged.
+    assert result is fake_results

From dec3c12a71c1fefc81f30768fe2aec8e48df2fb8 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Fri, 20 Mar 2026 14:05:17 -0400
Subject: [PATCH 11/13] Fix incorrect build_query test assertions

---
 .../api/services/test_embedding_services.py   | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/server/api/services/test_embedding_services.py b/server/api/services/test_embedding_services.py
index 8cbc1be9..dcbb2fc7 100644
--- a/server/api/services/test_embedding_services.py
+++ b/server/api/services/test_embedding_services.py
@@ -38,14 +38,13 @@ def test_build_query_authenticated_uses_or_filter(mock_objects):
 @patch("api.services.embedding_services.Embeddings.objects")
 def test_build_query_unauthenticated_uses_superuser_only_filter(mock_objects):
     # An unauthenticated user may only see files uploaded by superusers.
-    # The OR branch for the user's own files must NOT be present.
+    # The source uses a plain kwarg here (not a positional Q object), so the
+    # value lives in call_args.kwargs, not call_args.args.
     user = MagicMock(is_authenticated=False)
 
     build_query(user, EMBEDDING_VECTOR)
 
-    expected_q = Q(upload_file__uploaded_by__is_superuser=True)
-    actual_q = mock_objects.filter.call_args.args[0]
-    assert actual_q == expected_q
+    assert mock_objects.filter.call_args.kwargs == {"upload_file__uploaded_by__is_superuser": True}
     
 # Test application of annotate and order_by
 
@@ -86,16 +85,18 @@ def test_build_query_no_document_filter_when_both_none(mock_objects):
 @patch("api.services.embedding_services.Embeddings.objects")
 def test_build_query_guid_takes_precedence_over_document_name(mock_objects):
     # When both guid and document_name are provided, the guid branch runs and
-    # the document_name branch is skipped entirely (only two filter calls total).
+    # the document_name branch is skipped entirely.
     user = MagicMock(is_authenticated=True)
 
     build_query(user, EMBEDDING_VECTOR, guid="abc-123", document_name="study.pdf")
 
-    # Two calls: auth filter + guid filter. No third call for document_name.
-    assert mock_objects.filter.call_count == 2
+    # The auth filter fires on mock_objects.filter (call_count == 1).
+    # The document filter fires on the chained ordered_qs.filter — a different
+    # mock object — so mock_objects.filter.call_count stays at 1.
+    assert mock_objects.filter.call_count == 1
 
-    # The second filter must use upload_file__guid, not name.
-    # We follow the mock chain to the queryset that .annotate().order_by() returned.
+    # The document filter must use upload_file__guid, not name, and must be
+    # called exactly once (confirming document_name branch was skipped).
     ordered_qs = mock_objects.filter.return_value.annotate.return_value.order_by.return_value
     ordered_qs.filter.assert_called_once_with(upload_file__guid="abc-123")
 

From f9e890a21a3c716fe2bcfb17b8dfef92fcebb905 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Mon, 23 Mar 2026 14:43:39 -0400
Subject: [PATCH 12/13] Guard TransformerModel preload to runserver processes
 only

---
 server/api/apps.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/server/api/apps.py b/server/api/apps.py
index 4d502cba..d8b9eaa7 100644
--- a/server/api/apps.py
+++ b/server/api/apps.py
@@ -6,5 +6,28 @@ class ApiConfig(AppConfig):
     name = 'api'
 
     def ready(self):
+        import os
+        import sys
+
+        # ready() runs in every Django process: migrate, test, shell, runserver, etc.
+        # Only preload the model when we're actually going to serve requests.
+        # Dev (docker-compose.yml) runs `manage.py runserver 0.0.0.0:8000`.
+        # Prod (Dockerfile.prod CMD) runs `manage.py runserver 0.0.0.0:8000 --noreload`.
+        # entrypoint.prod.sh also runs migrate, createsu, and populatedb before exec'ing
+        # runserver — the guard below correctly skips model loading for those commands too.
+        if sys.argv[1:2] != ['runserver']:
+            return
+
+        # Dev's autoreloader spawns two processes: a parent file-watcher and a child
+        # server. ready() runs in both, but only the child (RUN_MAIN=true) serves
+        # requests. Skip the parent to avoid loading the model twice on each file change.
+        # Prod uses --noreload so RUN_MAIN is never set; 'noreload' in sys.argv handles that case.
+        if os.environ.get('RUN_MAIN') != 'true' and '--noreload' not in sys.argv:
+            return
+
+        # Note: paraphrase-MiniLM-L6-v2 (~80MB) is downloaded from HuggingFace on first
+        # use and cached to ~/.cache/torch/sentence_transformers/ inside the container.
+        # That cache is ephemeral — every container rebuild re-downloads the model unless
+        # a volume is mounted at that path.
         from .services.sentencetTransformer_model import TransformerModel
         TransformerModel.get_instance()

From 67176a8541be4d2862d213783873e1651f6fe761 Mon Sep 17 00:00:00 2001
From: Sahil D Shah <sahildshah1@gmail.com>
Date: Wed, 25 Mar 2026 16:42:20 -0400
Subject: [PATCH 13/13] Revert GitHub Workflow changes

---
 .github/workflows/python-app.yml |  9 ++-------
 evaluation/evals.py              | 16 ++++++++--------
 server/balancer_backend/urls.py  |  6 +++---
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index 2afa2828..dcb7a4bb 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -5,9 +5,9 @@ name: Python application
 
 on:
   push:
-    branches: [ "develop" ]
+    branches: [ "listOfMed" ]
   pull_request:
-    branches: [ "develop" ]
+    branches: [ "listOfMed" ]
 
 permissions:
   contents: read
@@ -27,8 +27,3 @@ jobs:
       run: pipx install ruff
     - name: Lint code with Ruff
       run: ruff check --output-format=github --target-version=py39
-    - name: Install test dependencies
-      run: pip install -r server/requirements.txt
-      # Pytest won’t automatically discover config files in subdirectories
-    - name: Run tests
-      run: pytest -c server/pytest.ini server/ -v
diff --git a/evaluation/evals.py b/evaluation/evals.py
index 5110076f..8eb7e9e6 100755
--- a/evaluation/evals.py
+++ b/evaluation/evals.py
@@ -21,18 +21,18 @@
 # Ensure the parent directory is in the path to import ModelFactory
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
-import argparse  # noqa: E402
-import logging  # noqa: E402
-import asyncio  # noqa: E402
-import time  # noqa: E402
+import argparse
+import logging
+import asyncio
+import time
 
-import pandas as pd  # noqa: E402
+import pandas as pd
 
 # lighteval depends on `sentencepiece` and it only has prebuilt wheels for Python 3.11 or below
-from lighteval.tasks.requests import Doc  # noqa: E402
-from lighteval.metrics.metrics_sample import Extractiveness  # noqa: E402
+from lighteval.tasks.requests import Doc
+from lighteval.metrics.metrics_sample import Extractiveness
 
-from server.api.services.llm_services import ModelFactory  # noqa: E402
+from server.api.services.llm_services import ModelFactory
 
 logging.basicConfig(
     level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s"
diff --git a/server/balancer_backend/urls.py b/server/balancer_backend/urls.py
index cdb92dbb..55bd2032 100644
--- a/server/balancer_backend/urls.py
+++ b/server/balancer_backend/urls.py
@@ -58,9 +58,9 @@
     path("api/redoc/", SpectacularRedocView.as_view(url_name="schema"), name="redoc"),
 ]
 
-import os # noqa: E402
-from django.conf import settings # noqa: E402
-from django.http import HttpResponseNotFound # noqa: E402
+import os
+from django.conf import settings
+from django.http import HttpResponseNotFound
 
 
 def spa_fallback(request):