🚧 add PioGrowth UI tests

.github/workflows/test_piogrowth_app.yml

@@ -0,0 +1,35 @@
+name: Test PioGrowth App
+
+on:
+  push:
+    branches: ["main", "dev"]
+    tags: ["v*.*.*"]
+  pull_request:
+    branches: ["main", "dev"]
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Test PioGrowth App (UI Tests)
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.14"]
+    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" # caching pip dependencies
+          cache-dependency-path: "**/pyproject.toml"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install pytest
+          pip install -e .
+      - name: Run tests
+        run: |
+          python PioGrowth/ui_tests/test_0_upload_data.py

PioGrowth/ui_tests/test_0_upload_data.py

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+"""Tests for the main app.
+
+As of now fileuploading cannot be tested.
+
+As long as local module (w.r.t to the app are used, the test script has to be in the
+same folder as the app).
+
+https://docs.streamlit.io/develop/concepts/app-testing/cheat-sheet
+"""
+
+from streamlit.testing.v1 import AppTest
+
+import piogrowth
+
+fname_data = "data/batch_example/example_batch_data_od_readings.csv"
+
+df_raw_od_data = piogrowth.load.read_csv(fname_data)
+msg = (
+    f"- Loaded {df_raw_od_data.shape[0]:,d} rows "
+    f"and {df_raw_od_data.shape[1]:,d} columns.\n"
+)
+# round timestamp data
+df_raw_od_data.insert(
+    0,
+    "timestamp_rounded",
+    df_raw_od_data["timestamp_localtime"].dt.round(
+        f"{5}s",
+    ),
+)
+
+
+def test_upload_page():
+    fname_app = "app/0_upload_data.py"
+    at = AppTest.from_file(fname_app).run()
+    assert not at.exception
+
+    assert at.markdown[-1].value == "### Store in QurvE format"
+    # cannot test file upload as of now
+    at.session_state["df_raw_od_data"] = df_raw_od_data
+    at.run()
+    assert not at.exception
+
+    # images and download buttons cannot be tested as of now
+    # ? Check for subheaders?