fix(analytics): enforce trustworthy chart rendering

tests/test_chart_fallback_contract.py

@@ -46,6 +46,11 @@ def test_chart_theme_has_cdn_timeout_and_fallback_sources():
     assert "cdn.jsdelivr.net/npm/chart.js@4.4.6" in script
     assert "unpkg.com/chart.js@4.4.6" in script
     assert "cdnjs.cloudflare.com/ajax/libs/Chart.js/4.4.6" in script
+    assert "!Array.isArray(ds.backgroundColor)" in script
+    assert "!Array.isArray(ds.borderColor)" in script
+    assert script.index("...originalScale") < script.index("border: { color: theme.faint")
+    assert "callback: v => formatNumber(v)" not in script
+    assert "autoSkip: true" in script
 
 
 def test_sales_chart_runtime_guard_rejects_axis_only_canvases():
@@ -55,3 +60,68 @@ def test_sales_chart_runtime_guard_rejects_axis_only_canvases():
     assert "colorPixels" in script
     assert "has no colored chart marks" in script
     assert "has no non-zero dataset values" in script
+
+
+def test_all_analysis_pages_have_runtime_chart_integrity_contracts():
+    script = (ROOT / "scripts" / "check_analysis_chart_integrity.js").read_text(encoding="utf-8")
+
+    for route in (
+        "/daily_sales?month=2026-04",
+        "/growth_analysis?start_month=2026-04&end_month=2026-04",
+        "/sales_analysis?start_date=2026-04-01&end_date=2026-04-30",
+        "/monthly_summary_analysis?start_month=2026-04&end_month=2026-04",
+    ):
+        assert route in script
+    for viewport in ("1440, height: 1000", "1024, height: 900", "390, height: 844"):
+        assert viewport in script
+    assert "loading overlay remains visible" in script
+    assert "has no colored chart marks" in script
+    assert "extreme percent values are not bounded with traceable markers" in script
+    assert "single point is not visibly emphasized" in script
+    assert "hides drawable payload behind an empty state" in script
+    assert "analysis tab lost the active period" in script
+    assert "rendered numeric indexes instead of product labels" in script
+    assert "contains labels outside the selected April period" in script
+    assert "explicitEmpty" in script
+
+
+def test_analysis_chart_failure_states_are_explicit_and_bounded():
+    sales = (ROOT / "web/static/js/page-sales-analysis.js").read_text(encoding="utf-8")
+    daily = (ROOT / "web/static/js/page-daily-sales.js").read_text(encoding="utf-8")
+    growth = (ROOT / "web/static/js/page-growth.js").read_text(encoding="utf-8")
+    monthly = (ROOT / "web/static/js/page-monthly-summary.js").read_text(encoding="utf-8")
+
+    assert "document.documentElement.dataset.salesCharts = 'ready'" in sales
+    assert "series.chart_values" in sales
+    assert "renderChartEmpty(bcgEl" in sales
+    assert "renderChartEmpty(hmEl" in sales
+    assert "originalValue" in daily
+    assert "clippedCount" in daily
+    assert "function dateAxis(element)" in daily
+    assert "overlapping date ticks" in (ROOT / "scripts/check_analysis_chart_integrity.js").read_text(encoding="utf-8")
+    assert "beginAtZero: true" in growth
+    assert "pointRadiusFor" in growth
+    assert "REQUEST_TIMEOUT_MS" in monthly
+    assert "activeFetchController.abort()" in monthly
+    assert "const refreshForViewport = () => {" in monthly
+    assert "const refreshForViewport = () => fetchData()" not in monthly
+    assert "dataset.monthlyCharts = 'ready'" in monthly
+    assert "safeHtmlText(p.value[3])" in monthly
+    assert "safeHtmlText(ps[0].name)" in monthly
+
+
+def test_analysis_tables_use_local_traditional_chinese_language_contract():
+    helper = (ROOT / "web/static/js/datatables-zh-hant.js").read_text(encoding="utf-8")
+    assert "window.EwoooCDataTableLanguage" in helper
+    assert "沒有符合條件的資料" in helper
+
+    assets = [
+        ROOT / "web/static/js/page-daily-sales.js",
+        ROOT / "web/static/js/page-sales-analysis.js",
+        ROOT / "web/static/js/page-monthly-summary.js",
+        ROOT / "templates/abc_analysis_detail.html",
+    ]
+    for asset in assets:
+        source = asset.read_text(encoding="utf-8")
+        assert "cdn.datatables.net/plug-ins" not in source
+        assert "EwoooCDataTableLanguage()" in source

tests/test_sales_chart_data_contract.py

@@ -0,0 +1,37 @@
+import pandas as pd
+
+from routes.sales_routes import _build_top_product_chart_data
+
+
+def test_top_product_chart_aggregates_sku_rows_before_ranking():
+    rows = pd.DataFrame(
+        [
+            {'pid': 'P1', 'name': '同名商品', 'amount': 100},
+            {'pid': 'P1', 'name': '同名商品', 'amount': 50},
+            {'pid': 'P2', 'name': '同名商品', 'amount': 90},
+            {'pid': 'P3', 'name': '獨立商品', 'amount': 200},
+            {'pid': 'P4', 'name': '零業績商品', 'amount': 0},
+        ]
+    )
+
+    result = _build_top_product_chart_data(rows, 'pid', 'name', 'amount', 'amount')
+
+    assert result['chart_values'] == [200.0, 150.0, 90.0]
+    assert result['labels'] == ['獨立商品', '同名商品 [P1]', '同名商品 [P2]']
+    assert result['metric_label'] == '銷售金額 ($)'
+
+
+def test_top_product_chart_returns_explicit_empty_contract():
+    result = _build_top_product_chart_data(
+        pd.DataFrame(columns=['name', 'amount']),
+        None,
+        'name',
+        'amount',
+        'qty',
+    )
+
+    assert result == {
+        'labels': [],
+        'chart_values': [],
+        'metric_label': '銷售數量',
+    }