fix: the weekly data anomaly detection was broken for the Svelte anomalies (#1983)

Co-authored-by: Alex Savelyev <91429106+alexdln@users.noreply.github.com>

Author: samal-rasmussen

app/utils/download-anomalies.ts

@@ -26,7 +26,9 @@ function getDateString(point: Record<string, any>, granularity: ChartTimeGranula
 }
 
 /**
- * For daily/weekly the point date falls strictly between the anomaly bounds.
+ * For daily the point date falls strictly between the anomaly bounds.
+ * For weekly the point date is the week start, and the full 7-day range is
+ * checked so any overlapping week is affected.
  * For monthly/yearly the anomaly bounds are truncated to the same resolution
  * so that any period overlapping the anomaly is caught (inclusive).
  */
@@ -37,8 +39,15 @@ function isDateAffected(
 ): boolean {
   switch (granularity) {
     case 'daily':
-    case 'weekly':
       return date > anomaly.start.date && date < anomaly.end.date
+    case 'weekly': {
+      const startWeek = date
+      const weekStartDate = new Date(`${date}T00:00:00Z`)
+      const weekEndDate = new Date(weekStartDate)
+      weekEndDate.setUTCDate(weekEndDate.getUTCDate() + 6)
+      const endWeek = weekEndDate.toISOString().slice(0, 10)
+      return startWeek <= anomaly.end.date && endWeek >= anomaly.start.date
+    }
     case 'monthly': {
       const startMonth = anomaly.start.date.slice(0, 7) + '-01'
       const endMonth = anomaly.end.date.slice(0, 7) + '-01'

test/unit/app/utils/download-anomalies.spec.ts

@@ -0,0 +1,64 @@
+import { describe, expect, it } from 'vitest'
+import { applyBlocklistCorrection } from '../../../../app/utils/download-anomalies'
+import type { WeeklyDataPoint } from '../../../../app/types/chart'
+
+describe('applyBlocklistCorrection', () => {
+  it('treats overlapping weekly buckets as affected anomalies', () => {
+    const data: WeeklyDataPoint[] = [
+      {
+        value: 100,
+        weekKey: '2022-11-07_2022-11-13',
+        weekStart: '2022-11-07',
+        weekEnd: '2022-11-13',
+        timestampStart: 0,
+        timestampEnd: 0,
+      },
+      {
+        value: 999,
+        weekKey: '2022-11-14_2022-11-20',
+        weekStart: '2022-11-14',
+        weekEnd: '2022-11-20',
+        timestampStart: 0,
+        timestampEnd: 0,
+      },
+      {
+        value: 999,
+        weekKey: '2022-11-21_2022-11-27',
+        weekStart: '2022-11-21',
+        weekEnd: '2022-11-27',
+        timestampStart: 0,
+        timestampEnd: 0,
+      },
+      {
+        value: 999,
+        weekKey: '2022-11-28_2022-12-04',
+        weekStart: '2022-11-28',
+        weekEnd: '2022-12-04',
+        timestampStart: 0,
+        timestampEnd: 0,
+      },
+      {
+        value: 200,
+        weekKey: '2022-12-05_2022-12-11',
+        weekStart: '2022-12-05',
+        weekEnd: '2022-12-11',
+        timestampStart: 0,
+        timestampEnd: 0,
+      },
+    ]
+
+    expect(
+      applyBlocklistCorrection({
+        data,
+        packageName: 'svelte',
+        granularity: 'weekly',
+      }),
+    ).toEqual([
+      data[0],
+      { ...data[1], value: 125, hasAnomaly: true },
+      { ...data[2], value: 150, hasAnomaly: true },
+      { ...data[3], value: 175, hasAnomaly: true },
+      data[4],
+    ])
+  })
+})