From b18b128e52fbb45d5322f2ca99075f2ec2c95043 Mon Sep 17 00:00:00 2001
From: Thomas Heartman <thomas@getunleash.io>
Date: Mon, 20 Oct 2025 12:17:18 +0200
Subject: [PATCH] feat: add median per week calculation for the new flags in
 production widget (#10829)

---
 .../calculateMedian.test.ts                   | 162 ++++++++++++++++++
 .../calculateMedian.ts                        |  27 +++
 2 files changed, 189 insertions(+)
 create mode 100644 frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.test.ts
 create mode 100644 frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.ts

diff --git a/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.test.ts b/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.test.ts
new file mode 100644
index 0000000000..635d9343f8
--- /dev/null
+++ b/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.test.ts
@@ -0,0 +1,162 @@
+import { calculateMedian } from './calculateMedian.ts';
+
+test('works with empty data', () => {
+    const result = calculateMedian([]);
+    expect(result).toBe('N/A');
+});
+
+test('correctly identifies the median in odd-length arrays', () => {
+    const data = [
+        {
+            data: [
+                {
+                    week: '2024-01',
+                    date: '2024-01-07 01:00:00',
+                    newProductionFlags: 99,
+                },
+                {
+                    week: '2024-02',
+                    date: '2024-01-14 01:00:00',
+                    newProductionFlags: 0,
+                },
+                {
+                    week: '2024-03',
+                    date: '2024-01-21 01:00:00',
+                    newProductionFlags: 3,
+                },
+            ],
+        },
+    ];
+    const result = calculateMedian(data);
+    expect(result).toBe(3);
+});
+
+test('correctly identifies the median in even-length arrays', () => {
+    const data = [
+        {
+            data: [
+                {
+                    week: '2024-01',
+                    date: '2024-01-07 01:00:00',
+                    newProductionFlags: 0,
+                },
+                {
+                    week: '2024-02',
+                    date: '2024-01-14 01:00:00',
+                    newProductionFlags: 10,
+                },
+                {
+                    week: '2024-03',
+                    date: '2024-01-21 01:00:00',
+                    newProductionFlags: 12,
+                },
+                {
+                    week: '2024-04',
+                    date: '2024-01-28 01:00:00',
+                    newProductionFlags: 50,
+                },
+            ],
+        },
+    ];
+    const result = calculateMedian(data);
+    expect(result).toBe(11);
+});
+
+test('handles single week data', () => {
+    const data = [
+        {
+            data: [
+                {
+                    week: '2024-01',
+                    date: '2024-01-07 01:00:00',
+                    newProductionFlags: 7,
+                },
+            ],
+        },
+    ];
+    const result = calculateMedian(data);
+    expect(result).toBe(7);
+});
+
+test('handles multiple projects with overlapping weeks', () => {
+    const data = [
+        {
+            data: [
+                {
+                    week: '2024-01',
+                    date: '2024-01-07 01:00:00',
+                    newProductionFlags: 11,
+                },
+                {
+                    week: '2024-02',
+                    date: '2024-01-14 01:00:00',
+                    newProductionFlags: 3,
+                },
+            ],
+        },
+        {
+            data: [
+                {
+                    week: '2024-02',
+                    date: '2024-01-14 01:00:00',
+                    newProductionFlags: 7,
+                },
+                {
+                    week: '2024-03',
+                    date: '2024-01-21 01:00:00',
+                    newProductionFlags: 100,
+                },
+            ],
+        },
+        {
+            data: [
+                {
+                    week: '2024-01',
+                    date: '2024-01-07 01:00:00',
+                    newProductionFlags: 1,
+                },
+                {
+                    week: '2024-04',
+                    date: '2024-01-21 01:00:00',
+                    newProductionFlags: 20,
+                },
+            ],
+        },
+    ];
+    const result = calculateMedian(data);
+    expect(result).toBe(16);
+});
+describe('handling weeks with no production flags data', () => {
+    test('it disregards solo entries without production flags data', () => {
+        const data = [
+            { data: [{ week: '2024-02', date: '2024-01-14 01:00:00' }] },
+        ];
+        const result = calculateMedian(data);
+        expect(result).toBe('N/A');
+    });
+    test('weeks without production flags data is disregarded in larger sets', () => {
+        const data = [
+            {
+                data: [
+                    { week: '2024-01', date: '2024-01-14 01:00:00' },
+                    {
+                        week: '2024-02',
+                        date: '2024-01-14 01:00:00',
+                        newProductionFlags: 7,
+                    },
+                    {
+                        week: '2024-03',
+                        date: '2024-01-21 01:00:00',
+                        newProductionFlags: 3,
+                    },
+                ],
+            },
+            {
+                data: [{ week: '2024-03', date: '2024-01-21 01:00:00' }],
+            },
+        ];
+
+        const result = calculateMedian(data);
+        expect(result).toBe(5);
+    });
+});
diff --git a/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.ts b/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.ts
new file mode 100644
index 0000000000..60efbc55af
--- /dev/null
+++ b/frontend/src/component/insights/componentsStat/NewProductionFlagsStats/calculateMedian.ts
@@ -0,0 +1,27 @@
+import type { WeekData } from 'component/insights/componentsChart/NewProductionFlagsChart/types.ts';
+
+export const calculateMedian = (
+    datasets: { data: WeekData[] }[],
+): string | number => {
+    const weekData: Record<string, number> = {};
+    for (const set of datasets) {
+        for (const { week, newProductionFlags } of set.data) {
+            if (newProductionFlags === undefined) {
+                continue;
+            }
+            weekData[week] = (weekData[week] ?? 0) + newProductionFlags;
+        }
+    }
+
+    const values: number[] = Object.values(weekData).toSorted((a, b) => a - b);
+    if (values.length === 0) {
+        return 'N/A';
+    }
+    const middle = Math.floor(values.length / 2);
+
+    if (values.length % 2 === 0) {
+        return (values[middle - 1] + values[middle]) / 2;
+    } else {
+        return values[middle];
+    }
+};