Fix flake8 F824 CI blocker and upgrade CI pipeline

.github/workflows/ci.yml

@@ -6,45 +6,66 @@ on:
   pull_request:
     branches: ["main", "master"]
 
-# Restrict default GITHUB_TOKEN permissions to read-only
 permissions:
   contents: read
 
 jobs:
-  lint-and-test:
+  lint:
     runs-on: ubuntu-latest
-    permissions:
-      contents: read
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Python
+      - name: Set up Python 3.12
         uses: actions/setup-python@v5
         with:
           python-version: "3.12"
+          cache: "pip"
+
+      - name: Install flake8
+        run: pip install flake8
+
+      - name: Lint — blocking (syntax errors / undefined names)
+        run: flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+
+      - name: Lint — style warnings (non-blocking)
+        run: flake8 . --count --exit-zero --max-line-length=100 --statistics
+
+  test:
+    needs: lint
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: "pip"
 
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements.txt
 
-      - name: Lint with flake8
-        run: |
-          pip install flake8
-          # Stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-          # Treat all other issues as warnings (non-blocking)
-          flake8 . --count --exit-zero --max-line-length=100 --statistics
+      - name: Run tests with coverage
+        env:
+          OPENAI_API_KEY: "offline-mode-no-key-required"
+        run: pytest test_chatbot.py -v --tb=short --cov=. --cov-report=xml
 
-      - name: Run tests
-        run: pytest test_chatbot.py -v
+      - name: Upload coverage report
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-${{ matrix.python-version }}
+          path: coverage.xml
 
   docker-build:
+    needs: test
     runs-on: ubuntu-latest
-    needs: lint-and-test
-    permissions:
-      contents: read
 
     steps:
       - uses: actions/checkout@v4

api.py

@@ -54,8 +54,6 @@ def clear_all_sessions() -> None:
 
 def _get_or_create_session(session_id: Optional[str]) -> tuple[str, ChatBot]:
     """Return (session_id, ChatBot) for the given session; create if missing."""
-    global _default_bot
-
     if session_id is None:
         # Create a new session
         session_id = str(uuid.uuid4())

requirements.txt

@@ -14,4 +14,5 @@ uvicorn[standard]>=0.23.0
 
 # Testing
 pytest>=7.4.0
+pytest-cov>=4.0.0
 httpx>=0.25.0