Added full suite of tests & added testing to CI/CD

.github/workflows/deploy.yml

@@ -19,8 +19,66 @@ on:
     - cron: '0 3 * * 0'
 
 jobs:
-  build-and-deploy:
+  # ========================================================================
+  # Job to run unit tests.
+  # ========================================================================
+  test:
+    name: Run Linters and Tests
     runs-on: ubuntu-latest
+    steps:
+      # Checks out the repo under $GITHUB_WORKSPACE
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      # Sets up Python 3.12 environment
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.12'
+          
+      # Cache pip dependencies for faster reruns
+      - name: Cache pip dependencies
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements*.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
+      - name: Install dependencies
+        working-directory: ./backend
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install -r requirements-dev.txt
+
+      - name: Lint with Ruff
+        working-directory: ./backend
+        run: |
+          ruff check .
+
+      - name: Check formatting with Black
+        working-directory: ./backend
+        run: |
+          black --check .
+
+      - name: Run Pytest
+        working-directory: ./backend
+        run: |
+          pytest
+
+  # ========================================================================
+  # Job to build and deploy the Docker image to mara.
+  # ========================================================================
+  build-and-deploy:
+    name: Build and Deploy
+    runs-on: ubuntu-latest
+    needs: test # Ensure tests pass before deploying
+
+    # Only run this job if triggered by a push to main or manual dispatch/schedule
+    # This prevents it running for PRs (eventually)
+    if: github.event_name == 'push' || github.event_name == 'workflow_dispatch' || github.event_name == 'schedule'
+
     steps:
       # Checks out the repo under $GITHUB_WORKSPACE
       - name: Checkout code