feat: add write_styled_excel utility for styled Excel exports #83

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_excel.py

@@ -0,0 +1,54 @@
+import io
+
+import openpyxl
+import polars as pl
+
+from src.utils.table import write_styled_excel
+
+
+def test_write_styled_excel_header_bold_and_color():
+    df = pl.DataFrame({"objet": ["marché A"], "montant": [1000.0]})
+    buf = io.BytesIO()
+    write_styled_excel(df, buf)
+    buf.seek(0)
+    wb = openpyxl.load_workbook(buf)
+    ws = wb.active
+    cell = ws.cell(row=1, column=1)
+    assert cell.font.bold is True
+    assert cell.fill.fgColor.rgb == "FFB33821"
+    assert cell.font.color.rgb == "FFFFFFFF"
+
+
+def test_write_styled_excel_data_cell_text_wrap():
+    df = pl.DataFrame({"objet": ["marché A"]})
+    buf = io.BytesIO()
+    write_styled_excel(df, buf)
+    buf.seek(0)
+    wb = openpyxl.load_workbook(buf)
+    ws = wb.active
+    cell = ws.cell(row=2, column=1)
+    assert cell.alignment.wrap_text is True
+
+
+def test_write_styled_excel_known_column_wider_than_minimum():
+    # "objet" a une largeur explicite (350px) > minimum (132px)
+    # "autre" n'a pas de largeur explicite → reçoit le minimum
+    df = pl.DataFrame({"autre": ["x"], "objet": ["y"]})
+    buf = io.BytesIO()
+    write_styled_excel(df, buf)
+    buf.seek(0)
+    wb = openpyxl.load_workbook(buf)
+    ws = wb.active
+    width_autre = ws.column_dimensions["A"].width  # colonne 1 = "autre"
+    width_objet = ws.column_dimensions["B"].width  # colonne 2 = "objet"
+    assert width_autre > 0
+    assert width_objet > width_autre
+
+
+def test_write_styled_excel_custom_worksheet_name():
+    df = pl.DataFrame({"col": ["val"]})
+    buf = io.BytesIO()
+    write_styled_excel(df, buf, worksheet="2025")
+    buf.seek(0)
+    wb = openpyxl.load_workbook(buf)
+    assert "2025" in wb.sheetnames